Mr Poo. A joke name my mate banded about when I said I was looking for a little roadster. His prophecy seems to have come true...
After a fairly brief but intense search, I stumbled upon this little, er, gem!
A very good petrolhead mate of mine lives just a couple of miles from where it was being sold, so he offered to go and have a nosey and check out the usual areas of the car for me. It all checked out OK and I agreed a price with the seller on the phone.
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Upon collection yesterday I found the roof pretty knackered but without leaks, all the mechanicals in good nick, new brakes all round, new tyres. That'll do me I thought. I'm not precious about cars, so as long as they are reliable and drive well I don't mind a bit of rough around the edges. With 128k on the clock, what do you expect.
I popped the frunk to show my partner the comedy storage amount, you know, ensure she knows immediately that she can't pack loads of stuff for weekends away, and it wouldn't click down again. Then I spotted the slam panel was bent. And the underside of the lid was silver. And what was left of the latch (broken spring) was welded to the slam panel :))
A bit of gaffer tape later and it was ready for the hour journey back up the M6.
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Weirdly it has a 6 speed box (02 plate) and the rear subframe is mint, so I have a feeling there have been some various swapsies back there at some point...
That plus the nearly new radiator, and the fact it drives extremely well, dead straight steering wheel, accelerates and brakes in a perfectly straight line and doesn't wander around when cruising, means perhaps the alignment has been done recently too, maybe as a result of said bump.
Stuff ordered so far:
- Can of tyre weld so I can bin off the spare.
- A bunch of frunk interior panel clips as virtually all of them are missing.
- A tub of HH-66 glue to repair the roof (the seller kindly gave me some spare vinyl he had from a previous repair). As you can probably guess I'm no stranger to the game of repairing vinyl soft tops!
- Two new tyres to get all 4 to match brand and model. The current fronts are new and 185/55s. I'm going to slap them on the rear and have purchased some 175/55s to go on the front. I know this is 'wrong', but at the risk of sounding a bit big headed, you can insert a famous Kimi Raikkonen quote here ;D
- A set of 4 dome headed push button bonnet pins / clips, so I can bin off the OE frunk lid mechanism. The two spares I may stick in the back lid if I can be bothered.
It could probably do with an oil and filter change so I know where I'm starting from, and I'll check the alignment too, then see where we're at.
So far I'm really, really impressed. This is my 4th mid engined roofless car (previously S2 Elise, Ferrari F430 and McLaren 650S), in addition to half a dozen MX4+1s and another front engined roofless car with the same 42:58% weight distribution, and have gelled with it pretty quickly! Toyota build quality shines through, everything works, driving position is great, all the controls have good ergonomics. Just need to check all the tyre pressures and send it down my local favourite roads to confirm the dynamics now ;)
Thanks to all who have helped so far, including those who have provided the extremely helpful guides and info on the forum. It really is appreciated.
def do the oil change.
Set of sparkies and air filter. Job done.
And a maf clean for good measure.
Well played not mentioning the storage bins behind the seats.
:)) Thanks.
Yeah, plan to get it up on the lift and serviced ASAP.
Just been out for a blast and it drives well. Pleasantly surprised by how much grip there is on China's finest rubber, and how communicative the car is. The whole 'snappy rear end' thing with road tyres and standard suspension doesn't really seem to be a thing, it gives loads of time and warning. Can definitely see how a stiff track setup with an inexperienced driver could lead to tears though!
I did however have an odd moment where the power steering couldn't keep up when applying a fast steering correction, and stiffened up the steering - tempted to remove the lot if I can find a way which will still pass the MOT next year.
The gears are terribly long! Couldn't believe what the speedo read at the top of 3rd. Wish I'd bought smaller tyres now ;D
As with every car that has ABS, its too intrusive for 'performance' driving, nibbling away when you want more rotational slip from the tyre than it will allow, so I need to find a way to switch that off when necessary. Perhaps splice into a sensor and run a switch to the dash - can anyone confirm that will work?
The roof wouldn't go down as the vinyl has gone so hard and stiff! So looks like I need to find time to pop to Swansea and something to do down there for 3 or 4 hours...
The todo list grows:
- Extra return spring on the throttle body as it lags a little when rolling off the throttle / changing gear.
- Set the pedals up properly. The throttle has a dead spot at the start (loose cable), and its resting position is nowhere near acceptable for heel and toe.
- Lube where the clutch slave pushes the release arm, if I can get to it. Pretty sure that's where the squeak is coming from, anyway...
- Turn up and fit some bushes for the end of the shift cable, too much fore and aft slop at the moment. Action is nice and smooth though and the gearbox feels good.
Quote from: AdamR28 on August 23, 2020, 21:26:)) Thanks.
Yeah, plan to get it up on the lift and serviced ASAP.
Just been out for a blast and it drives well. Pleasantly surprised by how much grip there is on China's finest rubber, and how communicative the car is. The whole 'snappy rear end' thing with road tyres and standard suspension doesn't really seem to be a thing, it gives loads of time and warning. Can definitely see how a stiff track setup with an inexperienced driver could lead to tears though!
I did however have an odd moment where the power steering couldn't keep up when applying a fast steering correction, and stiffened up the steering - tempted to remove the lot if I can find a way which will still pass the MOT next year.
The gears are terribly long! Couldn't believe what the speedo read at the top of 3rd. Wish I'd bought smaller tyres now ;D
The roof wouldn't go down as the vinyl has gone so hard and stiff! So looks like I need to find time to pop to Swansea and something to do down there for 3 or 4 hours...
The todo list grows:
- Extra return spring on the throttle body as it lags a little when rolling off the throttle / changing gear.
- Set the pedals up properly. The throttle has a dead spot at the start (loose cable), and its resting position is nowhere near acceptable for heel and toe.
- Lube where the clutch slave pusheds the release arm, if I can get to it. Pretty sure that's where the squeak is coming from, anyway...
- Turn up and fit some bushes for the end of the shift cable, too much fore and aft slop at the moment. Action is nice and smooth though and the gearbox feels good.
I struggle with heel and toe in mine. You finding the accelerator pedal to high?
- Lube where the clutch slave pusheds the release arm, if I can get to it. Pretty sure that's where the squeak is coming from, anyway...
It is and you can.
Quote from: JB21 on August 23, 2020, 21:36I struggle with heel and toe in mine. You finding the accelerator pedal to high?
Exactly that yeah. Possible with the side of the foot, but not exactly natural and I can probably only reach because my ankle ligaments are completely wrecked ;D
Likely solution will be to lift the brake pedal a bit using the clevis, bend the throttle pedal downwards and to the left, and maybe even put a small extension on the back of the throttle pedal, like this:
Needs a little nosey in the footwell sometime, but its always sortable somehow!
Sounds like a nice project :D
I really struggle with heal and toe in this car as well, the pedals are just to far apart for my little feet! at some point im going make accel pedal a bit wider as i think that would help for me.
I think even Bigfoot would struggle tbh!
Don't rule out making the brake pedal wider instead of the throttle, as an extra plate on top of it will also raise the height. IMO it's the most important pedal as it is safety related and you steer the car with it, so it needs to be the most obvious one down there.
Quote from: AdamR28 on August 23, 2020, 21:51Quote from: JB21 on August 23, 2020, 21:36I struggle with heel and toe in mine. You finding the accelerator pedal to high?
Exactly that yeah. Possible with the side of the foot, but not exactly natural and I can probably only reach because my ankle ligaments are completely wrecked ;D
Likely solution will be to lift the brake pedal a bit using the clevis, bend the throttle pedal downwards and to the left, and maybe even put a small extension on the back of the throttle pedal, like this:
Needs a little nosey in the footwell sometime, but its always sortable somehow!
Nice! Let me know once you have a fix :-)
Here's my pedal attachment. Had it on for years. Works a treat. Sorry for the fuzzy pics
Carolyn, I think I have seen that 2nd one hovering over area 51.....
Bought all the service bits at lunchtime today and made a quick start.
MAF looked like it had been the subject of a Kevin McCallister attack from a Home Alone film, and the air filter perhaps used to dig spuds out of the ground.
Spotted a reasonable leak from the engine / gearbox somewhere around the CV joint on the drivers side, another leak up front which can only be power steering fluid, a few more dents in the bodywork, and that the rear end is pointing a few degrees (yes, degrees, not minutes!) to the left. I have no idea how it drives in a straight line :))
It's a good job I enjoy messing with this stuff!
New 6PK1395 aux belt fitted as well, nice easy job and well worth doing as the old one looks like it might be the original! The tensioner pulley bearing is pretty shagged - need to investigate fitting new bearings to it, or try to get hold of a new pulley.
Is certainly going to keep you busy by the sounds of it! good work, keep it up :D
Quote from: AdamR28 on August 24, 2020, 15:26Bought all the service bits at lunchtime today and made a quick start.
MAF looked like it had been the subject of a Kevin McCallister attack from a Home Alone film, and the air filter perhaps used to dig spuds out of the ground.
Spotted a reasonable leak from the engine / gearbox somewhere around the CV joint on the drivers side, another leak up front which can only be power steering fluid, a few more dents in the bodywork, and that the rear end is pointing a few degrees (yes, degrees, not minutes!) to the left. I have no idea how it drives in a straight line :))
It's a good job I enjoy messing with this stuff!
Hi Adam the chain tensioner (lozenge with two nuts) sits above the drivers CV joint and are well known for leaking. Could be a good starting point. There is plenty of info on here about them. If I remember you need a slightly chunkier O-Ring than stock. The very knowledgable
@Carolyn has a post about it.
Quote from: Jamtastic on August 24, 2020, 17:29Quote from: AdamR28 on August 24, 2020, 15:26Bought all the service bits at lunchtime today and made a quick start.
MAF looked like it had been the subject of a Kevin McCallister attack from a Home Alone film, and the air filter perhaps used to dig spuds out of the ground.
Spotted a reasonable leak from the engine / gearbox somewhere around the CV joint on the drivers side, another leak up front which can only be power steering fluid, a few more dents in the bodywork, and that the rear end is pointing a few degrees (yes, degrees, not minutes!) to the left. I have no idea how it drives in a straight line :))
It's a good job I enjoy messing with this stuff!
Hi Adam the chain tensioner (lozenge with two nuts) sits above the drivers CV joint and are well known for leaking. Could be a good starting point. There is plenty of info on here about them. If I remember you need a slightly chunkier O-Ring than stock. The very knowledgable @Carolyn has a post about it.
Adam: PM me your address and I'll send an O ring. (FOC)
Great info
@Jamtastic , thank you. I'll have a look tomorrow!
Decided to to the plugs after work, good job as they look like they went down with the Titanic.
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Spark plug leads and coil loom plugs fitted with a generous smear / dollop of dielectric silicone paste. This stuff is great at keeping moisture out, so ideal given the MR2s engine bay open-ness, and also fills in the air gap around the electrical connection to give a more accurate spark.
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Loving the tool tray handily placed above the back box, and the screwdriver holders drilled in various areas of the chassis ;D
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Had a quick nosey at the alignment. Found a receipt in the paperwork that came with the car for a full alignment fairly recently. I didn't clock the name in the receipt, but might have been Stevie Wonder? 8)
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Readying myself for a bunch of other gremlins...
Edit: Posted at the same time as Carolyn... that is extremely kind, thank you! PM incoming...
@AdamR28 I know you are already on the case, but have to a say, a properly sorted geo on these cars makes a world of difference.
Absolutely, you preaching to the converted (I have a small / second hobby business which specialises in lightweight RWD sports car alignment) - can't wait to get it set up properly!
Have been researching a few bits this morning:
1. Front upper strut brace (there's a fair bit of scuttle shake going on)
2. Power steering removal (need to check with my local MOT garage if / how that can be made 'legal'...)
3. The chain tensioner O ring leak
4. Exhausts.
1. I'll DIY. The whole front of the car is out of line from that bump, so the frunk plastics don't fit properly any more. Plus, I'll be binning off the spare wheel in favour of an 'emergency' can, so I will have reasonable freedom to do what I want in this area. I figure 'something' will be a lot better than 'nothing' so I'm not going to go to town with a lavish solution, just a bit of tube (probably with pressed ends to match the OE rear brace) to support the strut tops a bit.
2. This looks straightforward having done the same job before on MX5s. I will test it out first with the 'roll along, clutch in, key out, start car again, look for PAS warning light' method, but I haven't found a sporty car I don't prefer with the PAS removed so I am hopeful.
3. Appears dead easy so will sort that when doing the oil change. Again big thanks to Carolyn for the O ring! What a great club - only hope I can help to repay these sorts of favours in future.
4. The car doesn't do anything at all for my aurally, so this needs addressing. I'm going to bang a budget de-cat manifold on there (fully expecting it to be total crap, so I will give it a good look over before fitment and Mr Welder and Mr Die Grinder will attack it if necessary), leave the mid section and standard cat in place, then build a simple cat back system with three 90 degree bends, a bit of straight pipe and an oval box, exiting under the bumper on the right, a bit like the Rogue Motorsport one: https://www.facebook.com/roguemotorsport/posts/new-product-mr2-roadster-performance-exhaust-silencer-440vatmr2-roadster-perform/1337347316326628/. I figure the weight saving can't be ignored too, the standard box looks massive!
I had the roof down yesterday and it has ripped considerably more while doing so, need to find an excuse to get down to Jack Smiths before the worst of the weather closes in! Pembrokeshire coast is lovely, so perhaps a weekend away is on the cards. The drive down all the way through Wales should be great too. Wonder if Ican sneak in a cheeky Pembrey or Llandow track day too...
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More parts on the way: Lambda sensor socket (previously just used a 22mm spanner but I might as well have the proper tool), new manifold, new aux belt tensioner pulley.
I usually don't do this as the result is often a bit scary, but here goes... Spends to date:
- Service parts (air filter, set of NGK plugs, 5L full syn 5w40 oil, filter, 2L full syn GL4 75w90 gearbox oil, spray can of electrical contact cleaner for the MAF): £83 (lucky enough to have a trade account with the local car spares place)
- Aux belt (6PK1395): £22
- 2x WhoFlungDung Ditchfinder Pros in the 'wrong' size: £64
- A tensioner pulley and a manifold that's probably total crap: £147
Total so far: £316
I'm loving this thread.
I mean this in a positive way; that car is a clip and it's great to see it be restored. I did the same with my old pre-fl which was in a similar state and it was rather nice when I was done
Re the swansea roof.
He has a waiting list which can be months long so best to ring him and have a chat to see how he is fixed and get on the list if needed.
That reminds of past threads
How much spent on vs actually bought for.
Moving on.
Haha, yes, it's even worse than I expected. A little disappointed in both myself and the seller - I bought the car unseen and the chap seemed genuine. Sadly there are a number of issues and 'clues' the car hasn't really been cared for, and I think the MOT is dodgy. But, it was my choice to buy it and I like a project, so lets crack on!
I have a bunch of photos and a larger write-up to do sometime soon, but for now...
- Idler pulley for aux belt: £31
- Stainless backbox (6x16", weld on): £45
Total so far: £392
I saw on Mr Smith's Facebook page (or somewhere like that) that his next availability is mid November at the moment. Crackers. May have to look at a more local but more expensive option...
Also, I am faced with the following with regards to trying to remove the OE heatshield in order to swap the manifold:
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My thoughts are to grind (flap wheel) the 'bolt heads' (very much a loose term now) off, then chop the heatshield into a few pieces and rip it away, hopefully enough so I can get to the head / manifold bolts. Any other ideas appreciated though!
Yep you gone have to cut that one off!
It may also succumb to drilling out which may be a less hazardous procedure than dissecting the heat shield. Advantage would be that you would retain the heat shield for your garage shelf. As you said you will be replacing the manifold so the threaded section does not have to be removed at this time.
I am aware that Mr Smith is popular but maybe still worth a telephone call.
Thanks guys. Grinder it is. Can't be arsed with drilling when there is a more destructive method which will do the same job :))
Anyway, after a couple of hours on Tuesday afternoon, Mr Poo now looks like this:
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Quite a sorry state all round, sadly, with some pretty big fluid leaks that have clearly been there a while. Perhaps not as much rust as some of the MX5s I have played with in the past, but being nearly 15 years younger I hoped it wouldn't be quite so crusty.
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Power steering lines are rotted through and weeping fluid.
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Clear evidence of the front end prang.
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Tensioner O-ring definitely needs doing (arrived today, thank you
@Carolyn !)
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Engine oil was absolutely grim, thick, gloopy and stinky. Seller told me he had it serviced in October. Methinks not...
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Aux belt tensioner pulley was knackered, and had a really weird bolt holding it on which I didn't have anything that would grip the head properly - apart from Mr Lathe!
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Luckily my hoarding instincts came in handy and I found a normal bolt.
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Shifter bushes were sloppy, so changed for 608 sealed cartridge bearings. These are a direct fit, 22mm OD, 8mm bore, just squeeze in with a set of mole grips. If anyone wants a pair of these at no cost let me know, have tons kicking about.
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In positive news, the gearbox oil is pretty fresh from when the replacement gearbox was fitted a few years back. Bizarrely though, there was a hiss when I undid the fill plug, yet the breather appears to be working just fine. Any ideas there?
Also fairly sure the car has a shirt shift kit fitted, the gear lever itself appears to be bent / curved, and it if's not a short shift then it is the shortest OE shift I've ever come across!
I have a relatively free weekend coming up, so plan to get stuck in and perhaps have it back on the road again for Sunday.
The to-do list stands at:
- Swap tyres over (the two current fronts will go on the rear, then two new tyres to go up front)
- Fit bonnet pins (if I can find anywhere to locate them in that awful mess of a front end)
- Remove PAS ('properly' - will pull the rack apart and remove the internal piston)
- Refill engine oil (have left the bottle on the drivers seat so I don't forget!)
- Swap manifold (the 'Three Amigos' came out really easily somehow - perhaps my special brew of 50:50 mix of acetone and ATF in a spray bottle, which always works brilliantly, was the key)
- Alignment (at this point we will see just how much of a dog the car is!)
- If the silencer I bought today arrives in time, cobble together a less muted cat back exhaust. Figured out I can just chop up the standard one, there's three 90 degree bends in there I can re-use, rather than shelling out 50 notes for new stainless elbows.
- Bleed / flush the clutch. My word that fluid is grim. Pretty sure its never been changed.
- Quick bleed of the brakes because they feel pretty naff.
- Cross my fingers that the other aux belt pulley I ordered arrives, fit that if it does.
- Sort the pedal setup, moving throttle pedal closer to the brake and closer to the bulkhead.
I think that's all for now... but as they say, jobs make jobs!
Wow even more to do that I thought!
I noticed a hiss when I undid filler plug on my gearbox as well, which I thought odd but couldn't see a reason for it.
Looks a lot of work involved there but hopefully worth it.
Plus, nothing can be as crusty as your average MX5 these days.
Good work! You'll have plenty satisfaction with the end result.
RE: the shifter - the standard shift lever/shaft is curved/bent, where the short shift kits have a straight lever/shaft.
Will be interested to hear how you find the bearings in the linkage. I'm going to do a back-to-back with bearings and poly bushes to see if there's any difference. Decent SKF or FAG sealed bearings only cost a few quid compared to £30+ for PU bushes, so it'll be interesting to see how they both feel.
On the clutch fluid - I haven't done it myself on one of these yet, but it seems to be imperative to have the car level if you're not using a vacuum pump, and don't let the reservoir run dry (which seems obvious but loads have fallen foul of it!).
Thanks for the info! Looks like it's a standard shifter then. Can't imagine why you'd want shorter than this, there is almost a borderline lack of feel as it is.
The bearings have made a huge difference over standard, enough that I won't play with it any more. There is now much less slop at this point of the linkage than elsewhere, so that'll do me.
Removed the PAS and sorted the bonnet pins this morning, then have been on a roadtrip with a mate for him to pick this up...
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Seems to have been an absolute bargain, very much the opposite of my recent purchasing experience!
Maurici also has my old tyre machine, so that helped get the Ditchfinder Pros find their new home.
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Quote from: Roj on August 28, 2020, 16:24Good work! You'll have plenty satisfaction with the end result.
RE: the shifter - the standard shift lever/shaft is curved/bent, where the short shift kits have a straight lever/shaft.
Will be interested to hear how you find the bearings in the linkage. I'm going to do a back-to-back with bearings and poly bushes to see if there's any difference. Decent SKF or FAG sealed bearings only cost a few quid compared to £30+ for PU bushes, so it'll be interesting to see how they both feel.
On the clutch fluid - I haven't done it myself on one of these yet, but it seems to be imperative to have the car level if you're not using a vacuum pump, and don't let the reservoir run dry (which seems obvious but loads have fallen foul of it!).
The genuine TRD short shifter has bends in it. I know'cos I've got one.
If you're lacking a bit of feel, may I suggest spray-lubing the external mechanisms on the gearbox?
Ah-ha, well maybe I'll whip the knob off to check it out sometime. Thanks!
Perhaps feel was the wrong word to use... its a nice action, smooth, tight; just right on the edge of too short to feel what the gearbox is doing, if that makes sense.
The standard shift lever is 19cm from the top of the side pivot to the top of the shaft.
People have also moved the pivot point by about 15mm using brute force to create their own quick shift kit.
Thanks! Had mine apart but forgot to measure, d'oh. Looks like it might be standard though.
Have ordered an extension to lift the knob up, for £7 it wasn't worth the lathe time!
Total spend now: £399
Ticked a load of jobs off this morning, now time for alignment (well, front and rear tracking, as nothing else is adjustable) and pedal setup, before a drive later. I may well get some camber bolts or tweak the camber in some other way if it needs adjustment and / or more camber.
Clutch fluid. Mmmmmm. Did the brakes too, one caliper had loads of air.
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Mr Angry Grinder sprinkled some of his magic dust in the engine bay, then the manifold was free (and bloody heavy)!
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Bleeding brakes and clutch with the aid of my leg extension. I always put the car on the lift the 'wrong' way!
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Shifter setup. Looks standard? Greased all the joints and took out those stupid rubber bobbins.
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Handbrake was having a hard time returning and couldn't be bothered to change the cable right now, so an MX5 handbrake return spring sprung into action to assist.
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Brilliant little set of tools from Teng, recommend everyone has one for fiddly jobs. Made removal of the centre console a breeze (without removing seats).
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Wheels balanced. The bubble balancer looks pikey, but I have seen them in the pits at an F3 race, and I've never had a wobbly wheel even well into 3 figure speeds (another car, on track).
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Pikey front strut brace knocked up, interior crap removed.
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Car back together now and back on wheels ready for alignment.
Lunch time!
Shifter looks standard to me. Making good progress!
Good to know - thanks!
Car is ready for a spin this evening...
Chucked her on the platforms, and checked the weight:
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Quite surprised at how light it is - this is with about 2/3rds of a tank (25kg) fuel on board:
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Then plonked my weight in the drivers seat (imperative for doing a proper alignment) - 3 bags of sand from B&Q is bang on my weight of 73kg.
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Which gave this... corner weights really quite close for a completely standard suspension setup. The cross within 0.5% is said to be a good target for setting up race cars (I would normally go to within 0.2%), so definitely happy with that!
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Toe done with a TrackAce laser tool - great bit of kit, especially for the cash. A little bit iterative and slower than a Hunter system, but gives perfect results with good care.
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Cambers and rear thrust measured & set up with my home made tool. Before above, after below. Had a faff around a lot to get any negative camber at the rear left. Perhaps some funny business going on there, I dunno. Looks like I will have to knock up some new longer / adjustable bottom arms if I'm going to get anywhere near enough camber to stop the car munching tyres on track.
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Now have two 205/50R15 tyres going spare if anyone needs them. A matching pair, about 5mm tread, date stamped 2018 from memory. Free to a good home!
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New back box arrived just as I was finishing up, so that's a job for another day...
Time for a drive 8)
Well. Mr Poo is getting less poo. The tweaks have all been in the right direction.
The exhaust was bugging me though. Such a flat and uninspiring sound. DPD man accidentally delivered the back box today, so with little else to do tonight I though I might as well get stuck in...
Old back box off. Crikey its a big un! Mr Grinder sprinkled his magic dust again, so the bends fell off.
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No wonder it sounded crap, there's a baffle directly at the inlet. I'm sure this improves low end grunt but... nah. Not for me.
Note light grey dusty powder. I'm assuming this is bits of broken down cat...
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A couple of hours later... voila. Not pretty by any means, but definitely lighter!
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Had to chop the bumper a bit. I'll tidy this up when it's not an unholy hour!
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Sounds tons better - pretty much as quiet as normal at low throttle / cruising, yet quite raspy when the engine is working hard - and I'm sure it flows more freely up the rev range...
Cheeky little 2nd gear pull. Much better!
Who makes the back box?
Every Exhaust Part: https://www.ebay.co.uk/itm/6-x-16-Weld-On-Stainless-Steel-Silencer-Exhaust-Box-Body-2-50mm-Bore/351568796766?pageci=174af29a-aa7c-438e-a053-e729d03e9837
Just totted up some weights from here: https://www.mr2roc.org/forum/index.php?topic=12479.0
Seems I've taken about 30kg out, plus whatever the difference in tyre weight is, so the standard car was about 970kg without fuel. Impressive.
Got a good few miles in today. Further impressions...
- The exhaust has got louder. Borderline chavvy, which isn't good. Have to see how that goes, might need to pop a small extra silencer in, think there's room between the current back box and the tailpipe.
- The dynamics of the car are excellent, but I can see how 'my first RWD' drivers run into issues. The weight at the back is noticeable and you have to know how to control its transfer to work for you, rather than against you.
- I really like the standard suspension setup, its firm enough to give good feedback but not awful and crashy like a lot of 'sports' cars. Blasting B roads is a dream thanks to a sensible ride height. Overall I think the best way to describe it is like a cross between my Elise and F430; which I guess it is in a lot of respects... apart from the obvious reduced worry of a hedge / pothole / stray sheep ruining the experience!
- There's grip for days even on the undersized (and Chinese crap) tyres, especially following confident prod of the throttle on corner exits. Kept getting ready to catch a slide, but nope... it does rotate nicely on the brakes however. Can't wait to get it on track.
- Staggered by the fuel economy, a hair under 30mpg over a full tank of mixed driving, obviously a fair bit of that 'exploring the performance' as always happens when you get a new car. Previous MX5s haven't got close to that.
- Still a bit unsure about the PAS delete, steering feels a tiny bit heavy on tight, slow corners. Will try a little more front camber before deciding for certain what to do.
- Scuttle shake & shimmy is still present. Needs under body bracing? Or will I not get rid of this without a hardtop?
- The front generates quite a lot of lift at higher speeds; maybe needs an undertray, splitter, or both.
- Ordered a sticker. Now spent £401.
I did wonder how you would find silencer, I had their extra quiet version and while it was okay at higher revs it was too loud for me at lower revs pottering about etc.
2 silencers I think are needed unless you turbo it which also quiets things :)
Light front end can be sorted by lowering, I found same before I fitted tein springs, better still when I added koni dampers.
Keep up the good work :)
Cheers Ian! I won't be lowering the car so I'll have to find another way...
Woke up early and thought I might as well make use of the quiet roads, so did a ~100 mile loop taking in some top local B roads before getting back to the workshop for 8.
Edit: not sure what's happened to this photo...!?
20200831_070151.jpg
The exhaust is absolutely fine with the roof on, and I've got used to it with the roof down now too. Over about 10% throttle it starts to make significant noises, but pottering it is quiet enough.
Fitted a switch to the dash to turn the ABS off on the fly (trackday use) - just breaks one of the wires to the front right sensor - and now have a bent paperclip jumper in the ashtray to turn the light off afterwards with (jump two pins in the OBD plug, ignition on, pump brake pedal to activate brake lights 8 times within 5 seconds, ignition off, jumper out, good to go).
Also (nearly) sorted the pedal setup.
@JB21 here's some pics / info for you.
I've bent the throttle pedal about half an inch to the left already, but the brake pedal was too low relatively. I looked at adjusting it by the clevis but resetting the brake light switch appears to be a pain, so went this route instead...
Ripped the crappy OE rubber thingy off. Those 4 holes came in handy after being drilled out to 5mm.
20200831_093031.jpg
90 degree drill attachment is a worthwhile tool to have!
20200831_095327.jpg
Transferred the hole pattern to a piece of paper using a centre punch...
20200831_095504.jpg
New brake pedal with holes countersunk, ready to accept bolts and spacers (these need to be about 10mm longer having just driven the car again).
20200831_102115.jpg
Fitted.
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And skateboard griptape added.
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Brake pedal sits about 40mm higher than the throttle at the moment. The brakes feel a bit mushy though, but not sure if that's due to an over-eager servo and they are all like that, or something is up with the brake system (car stops well!) - you can obviously play with the pedal height by changing spacers though.
Nice work on the brake pedal think i will do the same wider middle pedal and start without spacers first, my pedal is pretty solid and feels about right height wise when braking but need to look at that more, its just too far away from throttle for me to get my foot across to blip it on downshifts comfortably, i can do it but have to really work at it and with such aggressive pads in i need it to be easy and smooth.
Cheers - it's a bit of a 'formulaic' mod for me now, do the same thing on all cars as it just feels so much better, especially for left foot braking.
Sounds like you would benefit too, though try just bending the throttle pedal across a bit first (just give it a yank, by hand), that might do it!
Quote from: AdamR28 on August 30, 2020, 21:59Got a good few miles in today. Further impressions...
- The exhaust has got louder. Borderline chavvy, which isn't good. Have to see how that goes, might need to pop a small extra silencer in, think there's room between the current back box and the tailpipe.
- The dynamics of the car are excellent, but I can see how 'my first RWD' drivers run into issues. The weight at the back is noticeable and you have to know how to control its transfer to work for you, rather than against you.
- I really like the standard suspension setup, its firm enough to give good feedback but not awful and crashy like a lot of 'sports' cars. Blasting B roads is a dream thanks to a sensible ride height. Overall I think the best way to describe it is like a cross between my Elise and F430; which I guess it is in a lot of respects... apart from the obvious reduced worry of a hedge / pothole / stray sheep ruining the experience!
- There's grip for days even on the undersized (and Chinese crap) tyres, especially following confident prod of the throttle on corner exits. Kept getting ready to catch a slide, but nope... it does rotate nicely on the brakes however. Can't wait to get it on track.
- Staggered by the fuel economy, a hair under 30mpg over a full tank of mixed driving, obviously a fair bit of that 'exploring the performance' as always happens when you get a new car. Previous MX5s haven't got close to that.
- Still a bit unsure about the PAS delete, steering feels a tiny bit heavy on tight, slow corners. Will try a little more front camber before deciding for certain what to do.
- Scuttle shake & shimmy is still present. Needs under body bracing? Or will I not get rid of this without a hardtop?
- The front generates quite a lot of lift at higher speeds; maybe needs an undertray, splitter, or both.
- Ordered a sticker. Now spent £401.
Hi Adam
Glad to see it wasn't a total bag of nails in the end and your getting some enjoyment back.
I agree with what you say, it's such a communicative car. Amazing steering response and grip but still enough room to wag its finger at you if push it slightly too much.
Best compliment was when I drove a 430 on a track day experience, the instructor asked what car I drove, looked slightly surprised and said I'll be used to the handling then!
I run a hardtop at times, no difference unless it was permanently bolted on(Rogue Motorsport brackets?). As well testified on here underbody bracing definitely the way forward.
Thanks Jam - and for the bracing info. I've been having a nosey at various offerings today and I'm sure I'll get something knocked up in the coming weeks. May not end up pretty but it will be functional!
Have booked onto Oulton Park for 14th November, likely will give Mr Poo a run out as Xmas is a very busy time at work so a low-stress day (no trailer and associated hassle) will be just the job.
Quote from: AdamR28 on September 1, 2020, 19:56Thanks Jam - and for the bracing info. I've been having a nosey at various offerings today and I'm sure I'll get something knocked up in the coming weeks. May not end up pretty but it will be functional!
Have booked onto Oulton Park for 14th November, likely will give Mr Poo a run out as Xmas is a very busy time at work so a low-stress day (no trailer and associated hassle) will be just the job.
No worries pal.
I can talk a lot about not pretty but functional...
Hope it's a dry day at Oulton and you get to give it full sticks.
How are you getting on with the front end? Seen a lot of bodge tape in the pictures.
Cheers - to be honest I love it in the wet, though trying to escape black flags is usually the main concern!
Forgot to ipdate on the front end... I stuck some bonnet pins in. They were a bit short so I had to muller the bonnet a bit. The whole front end is out of line so I wasn't too precious about it. The pins / clips are really nice though, brilliant for the money. I'll grab a photo sometime.
Here's the front end now. Need to get rid of the gaffer residue! Also moved the plate up, why on earth it was blocking about a third of the grille I have no idea.
20200902_082839.jpg
Had an hour to play at lunch, so swapped the aux belt pulley and did some pondering about scuttle shake.
Concluded that 1) the reasons we experience difficulties are that there is no stiffness up high in the car, its basically a flat sheet with two sticky uppy bits at either end rather than a box - explains why a hardtop and the door bushings both help a lot and 2) the whole front end at suspension and steering rack level was little more than a trapezium, which may go some way towards explaining why the top (scuttle) does a little dance relative to the bottom (wishbone area).
So Mr Chop Saw, Mr Drill and Mr Welder were put to work, picking up the steering rack and lower front wishbone mounting points to tie everything into an X. Would have liked to go wider at the top, but the brake reservoir / lines and fuse box are very much in the way (have about 1/4" clearance).
20200902_150037.jpg
May do nothing, may do something, we shall see!
Still going to make some sort of mid brace as again I think that's an area of 'weakness'. With it being right in the middle of the car between the two main chassis loading points (suspension pickups), and being the weakest point thanks to the doors, it is under the highest torsional loading. Again explains why that particular brace seems to be well regarded as the 'go to'. Need to find some way of giving it a bit of depth if possible, to resist twisting. Don't mind losing a bit of ground clearance as I'll not be lowering the car, so even if that gives me an extra inch to play with (ooh matron), it'll help.
Edit: after a little spin tonight, I can't be sure if the X brace helps or not. Car feels noticeably less wibbly wobbly but not sure if that was because the roof was up! It's been down for the last 3 days, so I need to wait for another dry day and try again... the roof is also getting really quite bad now so I need to sort my life out and get booked in for a new one! Using quite a lot of gaffer tape 'repairing' it every time the roof goes back up!
20200902_204249.jpg
Managed to commute with the roof down on know roads this morning, fairly sure the brace makes a significant difference. There appears to be less 'noise' through the steering wheel and less shimmy. The true test will be when I take it off again for full closure!
Started investigating door bushes, as some support higher up from the floor pan seems like a quick and easy way to add some torsional stiffness.
Measured top and bottom door gaps while flat on the floor... drew a line so could repeat measurements at the same point.
20200903_084559.jpg
Then jacked the front right up 3"
20200903_084446.jpg
Before and after door gaps below.
20200903_090531.jpg
For anyone who can't read my scrawl (everyone?), the drivers door gap closed by 0.2mm at the top and opened up by 0.2mm at the bottom. Passenger side opened at the top and closed at the bottom, both by 0.1mm. All as you would expect having twisted the chassis in this plane.
Not a huge change but over the length of the car and with more of a 'whack' or some hard cornering loads, I can see why firming up the doors makes a difference. Perhaps a lump of blutak / plasticine stuck to the door jamb will reveal the true extent of flex following a spirited drive.
I'm liking your ways sir
Thanks!
No further progress on the door bushings, as I decided smacking my elbow on the centre console every time I shifted into 4th was more important.
Fitted the gear shift extender but it felt awful. Sloppy and way too much throw. So I ripped it all apart and sent everything for an appointment with Mr Grinder and Mr Welder.
20200908_111615.jpg
Then had a massive brain fart... :))
20200908_113504.jpg
Then sorted that out, chopped bits out of the plastic turret to make it all fit, raised it up a touch, and fitted the extender.
20200908_140631.jpg
Much better height now. Also cocked it over closer to the wheel.
20200908_135638.jpg
Shift throw length is pretty much the same as OE now, just obviously a lot higher up and smoother thanks to lashings if fresh grease on all the moving parts.
Also picked up a wind deflector (for some reason the car came without one!) locally for £12. So total spend now £413.
Booked in at Jack Smith's for a roof at the end of November, but did a shady repair for now using some cheapo vinyl the seller gave me with the car. That HH-66 glue is fantastic stuff, stuck absolutely solid!
20200908_145610.jpg
The random upside down extra strip was in case the glue didn't like the fuzzy texture underneath. Turns out I needn't have worried, but at least it should last a few months.
Looking, errmm, good?
Quote from: AdamR28 on September 2, 2020, 15:0720200902_204249.jpg
Haha. It's like the guy who did the previous alignment did my roof too!
As I said a pretty poor job, but better than this was the only aim, just need it watertight until November!
QuoteBrilliant little set of tools from Teng, recommend everyone has one for fiddly jobs. Made removal of the centre console a breeze (without removing seats).
@AdamR28 Can you give a bit more info on the Teng set?
Erm, not much more than it's very useful and worth having in your tool set!
https://www.ebay.co.uk/p/1346345019?iid=133325699166
Thanks, I forgot the pics would zoom out :doh
Quote from: AdamR28 on September 9, 2020, 09:08Erm, not much more than it's very useful and worth having in your tool set!
https://www.ebay.co.uk/p/1346345019?iid=133325699166
They're nice, a lot better than trying to use a bit in a ratcheting spanner.
Great work on the car so far btw. Wish I had welding skills!
All the best
Thanks
@iffyT , I count myself very fortunate to have the kit to allow me to play around with this stuff!
In related news... decided the front needed some bracing.
When fabbing stuff like this I always try to think in triangles, and about load paths, ensuring there is at least one member in tension and another in compression from all directions. This is obviously a quick and dirty version, especially as it was nice weather so i decided to weld outside and it was a but breezy, and its just blasted with a bit of ZG90 to 'finish', but it seems to make a difference; so I'm happy for the cost (nowt) and that it allowed me to spend a few hours tinkering with my dad.
20200910_143500.jpg
We also bled the brakes through with the car running, got quite a lot of air out of the NSR line but they still feel pretty mushy. Anyone got any tips?
Also heres my version of door bushings. Some simple lathe-turned lumps of nylon, one 15.0mm and the other 15.7mm, screwed into a rivnut. They are situated around twice as far up from the sill than the 'normal' ones, I figure this gives the best chance of stiffening the shell up.
20200910_152326.jpg
The doors are much tighter now, but still close with a solid thump under their own weight.
The main things I noticed so far are that the suspension now seems to be doing more work, and the dash rattles / squeaks more than before. Not sure if thats because everything else is now quieter or I've made something worse! ;D Front end and steering wheel shimmy appears to be reduced. Again, I'll run them for a bit and then take them off again for a proper comparison.
Have booked onto a track evening at Three Sisters, Wigan for 30th September.
@JB21 is booked on too, so it'll be good to have a nosey at a much better / nicer example of a '2 than mine!
Spend now £454 - bought some Apec brake pads all round, as the ones on the car are mismatched and unknown brand.
I know many will turn their noses up at the Apec 'budget' brand, but they are surprisingly good. I raced MX5s on them for years, both sprint and endurance, they hold up surprisingly well on track and have decent feel. For comparison, I found them to both last better and work better than EBC Yellows, especially from cold.
Quote from: AdamR28 on September 11, 2020, 11:02Spend now £454 - bought some Apec brake pads all round, as the ones on the car are mismatched and unknown brand.
I know many will turn their noses up at the Apec 'budget' brand, but they are surprisingly good. I raced MX5s on them for years, both sprint and endurance, they hold up surprisingly well on track and have decent feel. For comparison, I found them to both last better and work better than EBC Yellows, especially from cold.
Interestingly this. I've got yellows and find them pretty poor. Blues aren't bad at £70 for the front.
I think it's a case of all pads having a temperature level where they aren't comfortable any more, and from this point they increase in wear massively. This is often the leading edge of the pad too, so you end up with taper wear, sticky pistons, sticky sliders, and horrible brakes.
With the extra power in your car and stickier tyres, I wouldn't expect something like EBC Yellows to last very well, good to know the Blues are decent though if I need something more, thanks!
Do you find that fronts or rears wear out fastest?
Quote from: AdamR28 on September 11, 2020, 11:27I think it's a case of all pads having a temperature level where they aren't comfortable any more, and from this point they increase in wear massively. This is often the leading edge of the pad too, so you end up with taper wear, sticky pistons, sticky sliders, and horrible brakes.
With the extra power in your car and stickier tyres, I wouldn't expect something like EBC Yellows to last very well, good to know the Blues are decent though if I need something more, thanks!
Do you find that fronts or rears wear out fastest?
They wear fairly even front to back TBF. Blues front/Yellows rear lasted 8 track days and still had meat on them.
Awesome, thanks for the info, that is good news!
Quite different to a standard MX5 then where you'll get 2 or 3 days from a set of front pads (unless you spend well North of £100) and do 3 fronts to 1 rear...
I love seeing these home-brew 'built not bought' projectd and the ingenuity in some of the mods, great stuff. Can't wait until I get the space and kit to join the fun.
Quote from: Roj on September 11, 2020, 18:27I love seeing these home-brew 'built not bought' projectd and the ingenuity in some of the mods, great stuff. Can't wait until I get the space and kit to join the fun.
Agreed, the ability to DIY improve the MR2 is what is drawing me to one. That's what I loved about my two MX5, but that was ten years ago before everyone decided to skid them and drop them on eBay coilovers.
Thanks guys, glad to know my posts aren't going to waste :) I completely agree that older cars like this lend themselves perfectly to home tinkering.
In related news - oil consumption. I've been keeping an eye on it ever since I bought the car. It's been driven very hard at points and seems to have used the equivalent of approx 1l per 1000 miles, which is what Toyota claim is 'ok'. Not really sure I'm happy with that, given that every engine I've ever built (including race engines) uses absolutely zero oil. Mind you they get looked after properly and haven't done 130k!
Anyway, a quick peek inside the cylinders revealed it was pretty likely the oil control rings were in bad shape...
20200911_141215.jpg
So I bought a couple of bottles of Redex (spend now £459), pulled the plugs out, poured 30ml in each cylinder, turned the engine over a few times using the crank bolt to give the valves a bath too, wiggled the engine back and forth a bit to try and free up the oil control rings a little, then sucked a sample of the Redex back out to see what was happening.
20200911_150006.jpg
Something, definitely!
After the first 30ml shots had drained down into the sump, the process was repeated. Then, following a good check that all of the Redex had gone, the plugs etc. were put back in and the car fired up. A bit of stinky white smoke poured from the exhaust for a minute, but settled down just fine after that. Let it idle for 20 mins then dumped the oil in preparation for fresh fully synthetic 5w-40 and a new filter.
Its since been filled up with fuel, I dumped another half bottle of Redex in the tank, and thrashed the pants off it this morning.
Let's see how the oil consumption gets on now!
Ooo those pistons look nasty, the redex will clean crap off the top and might help a little with oil rings but will need to keep at it i think to have any real impact, having cleaned 2 sets of these now (out the engine) it gets pretty nasty and hard to remove even with scraper so too just to disolve it will take some time!, also coming at it from the top its got to get past compression rings which if in good shape wont let a huge amount past into oil rings below, good effort though and hopefully it makes a noticeable difference :)
Whether Redex works or not has been the subject of some discussion, I have been aware of it since the mid 50's when I remember my Father asking for a 1d shot to each gallon of petrol when filling up. I used it in my early cars, a Redex tune up by trickling Redex into the carburettor/ s while running the engine at a fast idle was certainly quite spectacular. Bore soaking as
@AdamR28 mentions above was also advocated although I have never tried it, but did consider it when SORN ing my 2, but never got around to it.
I stopped using it when I started driving company cars and have not returned to it since I retired, but for a product to have been around for so long, the company since 1920, there is likely something in the claims.
Quote from: thetyrant on September 13, 2020, 15:29hopefully it makes a noticeable difference :)
Cheers Ian, I hope it helps too! It took around an hour for 60ml (per cylinder) to drain through the combustion chambers, so I figure that's an hour the oil control rings were soaking in Redex - plus a bit of mechanical agitation. Given that the comparison photo above was taken around 10 mins into the first soaking, and that was just the Redex sitting on top of the piston, it must have done 'something'. We'll see soon enough I guess!
May also try some 50:50 Acetone:ATF mix in there at some point too, but I'll give this at least 500 miles first.
Over the years, I've tried all sorts to un-stick these rings. The only method that has ever worked is to take the pistons out.
Quote from: Carolyn on September 13, 2020, 17:21Over the years, I've tried all sorts to un-stick these rings. The only method that has ever worked is to take the pistons out.
And soak them in Redex 😉
Quote from: Joesson on September 13, 2020, 18:02Quote from: Carolyn on September 13, 2020, 17:21Over the years, I've tried all sorts to un-stick these rings. The only method that has ever worked is to take the pistons out.
And soak them in Redex 😉
JP1 jet fuel is my tool of choice.
I've never cleaned pistons, other than scrape the tops, only got as far as cylinder heads, but wondered whether a proprietary oven cleaner would clean pistons and be as efficient, but perhaps less aggressive, than mechanical means.
But I suppose once the components are on the bench a world of opportunities awaits.
Quote from: Carolyn on September 13, 2020, 18:06Quote from: Joesson on September 13, 2020, 18:02Quote from: Carolyn on September 13, 2020, 17:21Over the years, I've tried all sorts to un-stick these rings. The only method that has ever worked is to take the pistons out.
And soak them in Redex 😉
JP1 jet fuel is my tool of choice.
Is this available at a Halfords near me 😉
Quote from: Joesson on September 13, 2020, 18:10Quote from: Carolyn on September 13, 2020, 18:06Quote from: Joesson on September 13, 2020, 18:02Quote from: Carolyn on September 13, 2020, 17:21Over the years, I've tried all sorts to un-stick these rings. The only method that has ever worked is to take the pistons out.
And soak them in Redex 😉
JP1 jet fuel is my tool of choice.
Is this available at a Halfords near me 😉
Not quite, but your local Shell will have something similar(ish) coming out the black pump ;)
Paraffin is also very good at breaking down baked-on old engine oil. Top tip from my local oldskool machine shop.
I guess diesel, kerosene and that are all cousins, at the very least!
Spend now £432. I'm not a fan of all the crap that floats around in the crank case being sucked back into the intake tract (on any car), so bought a cheapo catch tank from eBay (still to be delivered).
My friend with the Smurfette MX5 also very kindly 3D printed me a new gear knob, which is super cool 8)
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I love this thread!! Despite everytime i see something new its gone wrong with the MR2 i feel kinda guilty.
Nice gear knob BTW! ::)
Oh. Smurfette has the engine in the right place... shame on you Adam!
Has a few blasts out in the car (about 150 miles total) since the oil treatment and I haven't seen the level drop on the dipstick yet, so we'll see.
Noticed the rear tyres were feathering a little on the outside edges already, so I decided it was time for more camber. Also tweaked the rear toe to zero to compensate.
DIY camber bolts made by machining the shank of the standard bolts (no loss in strength as I haven't gone down past the minor diameter of the thread) and then welding a lump on, and machining this back again to fit.
20200917_131035.jpg
Only needed an extra degree so that did the job nicely.
Also made a last minute decision made to do the Javelin sprint at Croft this weekend with
@Maurici The regs state adequate roll-over protection or a hard top needed for convertibles... so I have some hardtop mounts to pick up from Dick Sloane on the way (ish) and Ian (thetyrant) has been very kind in offering that we can swap his hardtop to my car and back again between runs - legend! 8)
I haven't been there for about 7 years it seems, from looking at my YouTube, so it'll be interesting to see if I can remember the track at all ???
Love having a 'proper' road car for stuff like this, the plan is to take in some of the finest Yorkshire moors roads on the way up, have a night away (pretty sure I booked a twin room for Saturday night mate...), do the sprint, then a cruise back. Packing was dead easy :))
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And finally... to help me get where I need to be this weekend, because I'm directionally challenged, a 3D printed phone holder (thanks again Maurici):
20200917_155145.jpg
Good skills on the bolts.
Hope you go well at Croft. I meant to book onto a track day there next weekend, but by the time I got round to it it was sold out. Will try and make it down there next year at some point as I think the rest of this year is a write off for travelling across the country.
Thanks! Yeah I guess Croft is your 2nd nearest track? Well worth a visit in that case.
Spend now £467 - bought a Land Cruiser towing eye on eBay for £8 delivered, appears to be the same one as the MR2 (I know an Aygo one fits, it's just a bit shorter), we'll see!
Fulled up with fuel again, over a total of 460 miles it's managed just shy of 32mpg. Again pretty impressed with that, given how hard some of that driving has been, and a good chunk of it short 15 minute commutes.
Fitted the Apec pads yesterday and the brakes feel much better already. Still weird and a bit spongy though, even having bled all 4 calipers twice (once with engine on, once with it off) so going to try 'bench bleeding' the master by connecting the front right caliper bleed nipple up to the reservoir using a long bit of hose, see if that's where the issue lies...
Famous last words - the brakes are now really quite bad! The car yaws to the right on application, which was pretty 'interesting' coming back via the moors on the trip back from Croft - and indeed at Croft too. I have a new rear caliper to go on (the driver's side seems pretty sticky) so fingers crossed that sorts it... Sort of feels like a loose suspension component though, so we'll see.
Backtracking a bit - Croft this weekend for the Javelin sprint. I'd arranged to go and see Dick Sloane on the way up to grab some hardtop mounts as Ian / thetyrant had been very kind in offering to let me borrow his, swapping it between our cars between runs. Thank you once again mate!
There were 12 cars in our class (J12), mostly Celicas with the 2ZZ engine, plus a few MR2s - one with 2ZZ (which should have been in the class above), Ian in his pretty standard car, myself - and Maurici in his 1.8 mx-engineinwrongplace . So that at least gave 3 cars of similar spec (driven there under their own steam, 140bhp, pretty close to standard) to play with.
20200920_091946.jpg
We had a lot of fun trading times all day and it was seriously close between Ian and myself in the end - just 0.07s separating us!
AdamR28 - 1:46.99 1:46.84 1:46.08 1:46.24
1:45.50TheTyrant - 1:47.30 1:46.88 1:45.65
1:45.57 1:45.61
Shame I didn't have time to find a way of bolting the GoPro in, as things were pretty 'interesting' trying to hustle the car on standard suspension and crappy Chinese undersized tyres!
Aside from the track action, it was brilliant to blast over the moors from Carlisle to Croft, and then back again through Catterick and Ingleton to Lancaster. It's been a while since I did this - more recently trailering everywhere - and I think there is huge merit in having less 'stuff' in tow and just enjoying the car.
I can't 'enjoy' it too much on track in it's current guise though - those DitchFinder Pros I fitted really do not like being driven hard! After just 6 laps of Croft the left hand ones are pretty mullered, so I'm on the lookout for a second set of PFL wheels (any condition) if anyone has a set going spare.
To try and protect them a bit (or at least the outside edges) I plan to beef up the ARBs a bit before 3 Sisters next Wednesday. I still don't want to lower the car as the current ride height is so good for B road blasting, it just needs a bit more 'response' and to corner a touch flatter.
Oil - I don't think I had it on a flat surface when I checked at Croft, but it does appear to still be burning a bit. By that I mean maybe 4-500ml in 300 miles. Ha. Again we'll see when I check it on the level later. I'm still going to try and free up the rings a couple more times, but after that it will just be left to get through my special 1ZZ oil burner juice until I decide what to do with the car long term.
Under £80 delivered for this lot!
IMG-20200917-WA0015.jpeg
I do have a 'spare' CBR1000RR engine knocking about, that could be interesting... 'Only' 78lb/ft at the crank compared with ~120 for the current engine, but with the 1.604 main reduction ratio that actually gives a smidge more than the 1ZZ at the hubs, and of course more power once wound up to 13000rpm.
I fitted one of these to a Westfield last year, and it goes pretty well...
Think the guy in the 2zz MR2 was in J11 for the previous round at 3S and came 3rd out of 3 car inc another 2zz mr2, so why they stuck him in J12 for Croft is a bit strange. Presume he won the J12 class?
Hmm bike engine was something i considered for mine last year and while it would be hard work on road it would be fun on track im sure, also loose some weight out as well :D
Good effort at Croft though look forward to more battles...maybe you should go for 145's all round next time though :D
Have used a few BECs on the road and they are fine actually - earplugs can be helpful though for long motorway drives! I just don't think you can beat the combination of ~170bhp and a 6 speed sequential all for 70kg and less than a couple of grand, it's nuts.
Haha. I have some 155s on a set of steelies on my Micra and the wheels will swap straight over. Perhaps I should do that :))
@AdamR28 Do give the rear suspension a good check over with the torque wrench.
A few have reported similar feelings. Then found things not ad tight as they thought.
Thanks - would certainly explain the hideously lairy oversteer on every left hand corner at Croft!
Well. I think I've hit a turning point with the car. And I now know why it was such a handful on Sunday!
I've had this before - where one bushing indicates the condition of the rest of them... unless the lower front bush on the upright is 'known' for going? 7U in this diagram.
(https://mr2-ben.co.uk/uploads/image/file/590/polybush_mr2_roadster_2000_Toyota3.jpg)
Given the obviously chequered past and current foibles of Mr Poo, I am now considering buying a whole new car and combining the best bits into one, leaving me with some spares and a few bits to sell.
The alternative is to keep ploughing time and money into him; either sorting issues as they crop up, or rebuilding the whole thing to avoid being stranded miles from home, at a circuit, or worse having something completely fail while 'pressing on'.
Everything is already stripped down ready to accept a new bush if I go that route, but it needs some thought. The wheel bearing is on it's way out as well - I think the car is just generally a bit knackered.
In tyre wear news. From new to that in a little over 500 road miles and 10 minutes on track. And the front is even worse! Mental.
20200922_133155.jpg
@AdamR28 Pleased that your not giving up but just regrouping.
@The Arch Bishop has two 2's and has fallen out of love with one because of the rear hand brake and is thinking of putting it up for sale.
Just saying!
Well if you're interested, I'm fairly sure we can come to a very agreeable arrangement...
Quote from: AdamR28 on September 22, 2020, 14:54Well. I think I've hit a turning point with the car. And I now know why it was such a handful on Sunday!
I've had this before - where one bushing indicates the condition of the rest of them... unless the lower front bush on the upright is 'known' for going? 7U in this diagram.
(https://mr2-ben.co.uk/uploads/image/file/590/polybush_mr2_roadster_2000_Toyota3.jpg)
Given the obviously chequered past and current foibles of Mr Poo, I am now considering buying a whole new car and combining the best bits into one, leaving me with some spares and a few bits to sell.
The alternative is to keep ploughing time and money into him; either sorting issues as they crop up, or rebuilding the whole thing to avoid being stranded miles from home, at a circuit, or worse having something completely fail while 'pressing on'.
Everything is already stripped down ready to accept a new bush if I go that route, but it needs some thought. The wheel bearing is on it's way out as well - I think the car is just generally a bit knackered.
In tyre wear news. From new to that in a little over 500 road miles and 10 minutes on track. And the front is even worse! Mental.
20200922_133155.jpg
Wow that tyre has more or less melted! That's nuts
A parts donor or better condition chassis (The bucket) sounds like a good plan. Poor Mr Poo has lived a tough life it seems, and now you've pretty much driven the wheels off it. As you said a stranding or catastrophic failure on track would not be good.
I guess it would become the Poo Bucket? fetching name.
It will be worth it I would say, you certainly seem to be enjoying your MR2.
I would also like to be able to continue living vicariously through your real-life Forza motorsport exploits!
Quote from: iffyT on September 23, 2020, 09:34I guess it would become the Poo Bucket? fetching name.
I would also like to be able to continue living vicariously through your real-life Forza motorsport exploits!
:)) Excellent. Two perfect reasons...
Quote from: Joesson on September 22, 2020, 16:25@AdamR28
Pleased that your not giving up but just regrouping.
@The Arch Bishop has two 2's and has fallen out of love with one because of the rear hand brake and is thinking of putting it up for sale.
Just saying!
Thank you for the heads up on this!
Quote from: AdamR28 on September 23, 2020, 16:27Quote from: Joesson on September 22, 2020, 16:25@AdamR28
Pleased that your not giving up but just regrouping.
@The Arch Bishop has two 2's and has fallen out of love with one because of the rear hand brake and is thinking of putting it up for sale.
Just saying!
Thank you for the heads up on this!
I do hope it proves beneficial for you and The Arch Bishop and that the logistics are manageable.
Thank you - looks like logistics can be solved via a few trains this coming Tuesday, followed by a pretty long drive home! My dad lives around an hour from Lee, so I may try to combine collection with a visit to him as well.
Total spend now £797. Quite a big jump, yes... Some of that is the new rear bushes I've just fitted, and some front ARB drop link polybushes to firm things up a bit, but...
I'd been having a nosey at some photos from Croft, and while I do like a bit of body roll - it lets the driver feel what's going on, making the car a lot of fun - having the door handles nearly scraping on the floor isn't great for tyre wear, especially with the mac strut suspension system having less camber correction than a 'proper' dual wishbone setup like on, say, an mx-engineinwrongplace .
All aboard the HMS Poo - hideous amounts of body roll even pre-apex :))
50370906783_b1c457a6f0_c.jpg
50370906703_165d68f91e_c.jpg
Then, today an email came through from PayPal with a voucher for an account I hadn't used for a while. And an email from Part-Box, a company I have an account with but rarely use, who do Whiteline. So, I have a set of ARBs and proper camber bolts on the way.
The MR2 is a properly, properly good car. I am now convinced better than an mx-engineinwrongplace ! So I'm all in - and in building the Poo Bucket (thanks
@iffyT :)) ) I am sure I'll end up with a fairly sorted example (or at least one that keeps oil in it, rain water out of it, and has wheels that don't waggle about too much) - it would be a tragedy not to get the handling properly dialled in.
I don't want to go coilovers or drop the car on springs as it is so good for B road blasting, so I'm hoping the ARBs will add the taughtness I fancy (and the tyres are literally crying out for) without making things all crashy and bashy when the pavement isn't smooth. We'll see.
In oil news - it's still above the 'blob' on the end of the dipstick - a few hundred mil over max - not as bad as I expected. And that's with the oil cold - I'd last checked it warm. Perhaps all the spanking is loosening up those 18 years of crud a bit...
@AdamR28 Hope all goes well for you. You may or may not be aware that some rail tickets are available on line at lesser cost than at the station. Otherwise get to the station a little in front of time as when I went to collect my 2 the ticket office was closing, early, and the "gentleman" had cashed up and really didn't want me to buy a ticket. I had to convince him that plastic payment would not affect his cash balance too badly. That was the only problem in my collection trip and I drove the 100 miles home, top down, my first experience of such, uneventfully.
Thanks for the heads up once again! Decided to play it safe and get tickets in advance, wasn't too expensive in the end.
Mr Poo has been thoroughly spanked again tonight, this time a track evening at Three Sisters. Great to meet you
@JB21 and share some track time too!
20200930_204007.jpg
Doesn't look to bad in the dark, does he?
Mr Poo is now on SORN and unlikely to see the road ever again, which feels like a bit of a shame, but he will live on in a new guise...
Anyway, I have a long journey tomorrow to go and see a man about a Bucket, so best get to bed!
Good to meet you
@AdamR28. Your car didn't look out of place one bit and was flying on track. Bet it surprised a lot out there.
Thanks for the help after my crash as well.
Got home fine. Amazingly drives straight and true.
I was very lucky I think.
Just got on it to early and kept my foot in, by the time I could react it was to late. Lesson well and truly learnt.
In the dark, didn't expect that.
I could have stuffed it up much sooner.
Take it you and 2 are OK.
Quote from: Ardent on September 30, 2020, 23:34In the dark, didn't expect that.
I could have stuffed it up much sooner.
Take it you and 2 are OK.
All good mate thank you 👍
Cheers man, yeah standard suspension works well at 3 Sisters!
Very sorry to see you in the bump, and also not sure if I should have been the one to mention it first so didn't, but really glad there doesn't seem to have been any serious damage to both you and the car!
Hope you can get the bits for it easily.
As alluded to in a previous post, Mr Poo will now be resigned to track duties. The Bucket is so much nicer in pretty much every way, so my plan to have 2 Become 1 (if you sang that as if you were Mel C, kudos) is now in the bin - leaving one pretty much standard road car (El Bucketo), and another one that will need trailering around to get anywhere fun (Mr Poo).
Now, I have a history of 'improving' (wrecking?) cars, making the most of what's at my disposal without throwing all the go-faster bits China's aftermarket car parts division can muster at the project. The MunteR2 will be no exception (I hope!).
Munter? Yes, this is the affectionate name given to a previous mx-engineinwrongplace I 'munterised'. I was racing Mk1s at the time, and my self-imposed challenge was to build a track car for under £1000 that was faster round track than a 'proper' race car. Glad to say I succeeded, but the aforementioned Mr Wonder who did the geo on Mr Poo probably is the only man in existence who will approve at the cosmetics.
If you're the sort of person who gets precious about cars, you should probably now scroll up rather than down, close your browsing window immediately, and never come back here...
My own little £500 Bargain Bucket went from this:
red.jpg
To this, in 5 weeks:
munter1.jpg
And then it now looks like this, after a few years of 'special care' (huge thanks to my mate Mark who stuck it in the tyres at Cadwell - seriously, I think it looks better for a little track-based patina):
munter2.jpg
Sparse.
munterint.jpg
But surprisingly rapid, due to tiny wheels dropping the gearing down, just 802kg of weight, and the MX5s famous handling characteristics:
Which also allowed it to do this:
There's a build thread here for insomniacs: https://www.mx5nutz.com/forum/index.php?showtopic=216681
Anyway, as you can see, it's been a heck of a lot of fun - for everyone who has spent time in either seat. Going sideways a lot while barely sipping fuel, gradually whittling down brake pads, hardly shaving rubber off the tyres, and needing little else in terms of attention - but all things must come to an end at some point. With the itch for a winter project, the Munter is now being given away to a new home and Mr Poo will fill his comedy boots.
Given that she (Mr Poo has decided he / she wants to become non-binary, such is the modern age) is already sitting around 935kg, from some very quick maths I think the final weight figure MIGHT even start with a 7... That is a tough target, and I won't be disappointed if I don't quite get there, but it's worth a shot.
Here's what I have in mind to start with (silver car used for the image because it's the best one I could find in Google!).
MunteR2b.jpg
Of course
all the interior will come out (dash, carpets, plastics, radio, heater, etc), doors will be completely skinned, swap the steering wheel to a decent one, rip the ABS and handbrake systems out entirely, ditch the radiator fans, swap the battery for an ickle baby one, and build a neat roll cage to offer occupant protection as well as adding some 3rd polar stiffness to the (let's be honest, pretty floppy) chassis.
Like the Munter, I won't be lobbing any / many Max Power 'go-faster' bits at the car. I'll stick with standard dampers, ARBs, standard brakes and road pads, standard wheels and decent quality road tyres - I don't believe any of these bits make a car more fun, even if they do increase the car's performance (whether the driver can exploit this, is another discussion for another day...).
Hoping to get some time this week to begin the fun bit - the tear-down! If anyone does want any interior bits just let me know and I'll hang onto 'em, they're all free of course.
Quote from: AdamR28 on October 5, 2020, 16:12As alluded to in a previous post, Mr Poo will now be resigned to track duties. The Bucket is so much nicer in pretty much every way, so my plan to have 2 Become 1 (if you sang that as if you were Mel C, kudos) is now in the bin - leaving one pretty much standard road car (El Bucketo), and another one that will need trailering around to get anywhere fun (Mr Poo).
Now, I have a history of 'improving' (wrecking?) cars, making the most of what's at my disposal without throwing all the go-faster bits China's aftermarket car parts division can muster at the project. The MunteR2 will be no exception (I hope!).
Munter? Yes, this is the affectionate name given to a previous mx-engineinwrongplace I 'munterised'. I was racing Mk1s at the time, and my self-imposed challenge was to build a track car for under £1000 that was faster round track than a 'proper' race car. Glad to say I succeeded, but the aforementioned Mr Wonder who did the geo on Mr Poo probably is the only man in existence who will approve at the cosmetics.
If you're the sort of person who gets precious about cars, you should probably now scroll up rather than down, close your browsing window immediately, and never come back here...
My own little £500 Bargain Bucket went from this:
red.jpg
To this, in 5 weeks:
munter1.jpg
And then it now looks like this, after a few years of 'special care' (huge thanks to my mate Mark who stuck it in the tyres at Cadwell - seriously, I think it looks better for a little track-based patina):
munter2.jpg
Sparse.
munterint.jpg
But surprisingly rapid, due to tiny wheels dropping the gearing down, just 802kg of weight, and the MX5s famous handling characteristics:
Which also allowed it to do this:
There's a build thread here for insomniacs: https://www.mx5nutz.com/forum/index.php?showtopic=216681
Anyway, as you can see, it's been a heck of a lot of fun - for everyone who has spent time in either seat. Going sideways a lot while barely sipping fuel, gradually whittling down brake pads, hardly shaving rubber off the tyres, and needing little else in terms of attention - but all things must come to an end at some point. With the itch for a winter project, the Munter is now being given away to a new home and Mr Poo will fill his comedy boots.
Given that she (Mr Poo has decided he / she wants to become non-binary, such is the modern age) is already sitting around 935kg, from some very quick maths I think the final weight figure MIGHT even start with a 7... That is a tough target, and I won't be disappointed if I don't quite get there, but it's worth a shot.
Here's what I have in mind to start with (silver car used for the image because it's the best one I could find in Google!).
MunteR2b.jpg
Of course all the interior will come out (dash, carpets, plastics, radio, heater, etc), doors will be completely skinned, swap the steering wheel to a decent one, rip the ABS and handbrake systems out entirely, ditch the radiator fans, swap the battery for an ickle baby one, and build a neat roll cage to offer occupant protection as well as adding some 3rd polar stiffness to the (let's be honest, pretty floppy) chassis.
Like the Munter, I won't be lobbing any / many Max Power 'go-faster' bits at the car. I'll stick with standard dampers, ARBs, standard brakes and road pads, standard wheels and decent quality road tyres - I don't believe any of these bits make a car more fun, even if they do increase the car's performance (whether the driver can exploit this, is another discussion for another day...).
Hoping to get some time this week to begin the fun bit - the tear-down! If anyone does want any interior bits just let me know and I'll hang onto 'em, they're all free of course.
Brilliant!
Great driving - thoroughly enjoyed watching that, thanks. ;D
Superb, I love this ethos!
He actually posted a picture of a eunos roadster.
I feel physically sick.
@shnazzle permaban alstublieft liefde.
With a nod to our resident weight watcher
@Petrus I don't know what a !**!nus weighed to begin with, but after a dose of adding lightness. (802kg :o) In my small brain that is like an upgrade to the brakes. They have less to stop. Basic, but that's how my mind works.
Edit
little addition for clarity
Quote from: Ardent on October 5, 2020, 22:21With a nod to our resident weight watcher @Petrus
I don't know what a !**!nus weighed to begin with, but after a dose of adding lightness. In my small brain that is like an upgrade to the brakes. They have less to stop. Basic, but that's how my mind works.
The kinetic energy in a moving is linear with the mass. Thus the energy that needs to be dissipated by the brakes is too.
An added factor is tyre load sensitivy of rúbber which means that the friction coëfficient deminishes with oncreased load. This means that a heavier load on the tyres reduced the max. force that can be tranmsmitted by the tyres. This means that a lighter can can transfer more.
Thus the brakes of a lighter car have more braking potential on both the less energy to dissipate and the higher level that can be.
Yep, Ke=MV^2.
Doing some lightening improves everything. Whereas adding power only improves one thing, while increasing wear and tear to other bits.
@AdamR28 Do you think you can get it to 200bhp per ton?
Good to see you are committed to some proper craziness! Carry on good sir.
If you ever come down south for a track day, I want to have a ride!
Quote from: Petrus on October 5, 2020, 22:40Quote from: Ardent on October 5, 2020, 22:21With a nod to our resident weight watcher @Petrus
I don't know what a !**!nus weighed to begin with, but after a dose of adding lightness. In my small brain that is like an upgrade to the brakes. They have less to stop. Basic, but that's how my mind works.
The kinetic energy in a moving is linear with the mass. Thus the energy that needs to be dissipated by the brakes is too.
An added factor is tyre load sensitivy of rúbber which means that the friction coëfficient deminishes with oncreased load. This means that a heavier load on the tyres reduced the max. force that can be tranmsmitted by the tyres. This means that a lighter can can transfer more.
Thus the brakes of a lighter car have more braking potential on both the less energy to dissipate and the higher level that can be.
That nearly makes me feel smug with myself. I was right. Even if I couldn't explain why. :)
Quote from: Ardent on October 5, 2020, 23:00That nearly makes me feel smug with myself. I was right. Even if I couldn't explain why. :)
Even just by intuition it is obvious that:
A car weighing 15% less has
1. 15% less kinetic energy to be dissipated
2. a roughly 5% higher friction coëfficient = 5% more energy which can be transferred to the road.
= 20% shorter stopping distance from same speed with same tyres.
Even from only 60 mph that makes 100 feet 80 feet: Uffff!!!!
Now matter how small the win I'll take it.
On the basis.
There is nothing so simple it cannot be misunderstood.
A previous thought for the day.
Quote from: Petrus on October 5, 2020, 23:38Quote from: Ardent on October 5, 2020, 23:00That nearly makes me feel smug with myself. I was right. Even if I couldn't explain why. :)
Even from only 60 mph that makes 100 feet 80 feet: Uffff!!!!
A nice way to envision this is to imagine an obstacle 80ft away. The lighter one will stop just in time, the other will hit the obstacle at probably double-digit speed.
Quote from: iffyT on October 5, 2020, 22:57Yep, Ke=MV^2.
Doing some lightening improves everything. Whereas adding power only improves one thing, while increasing wear and tear to other bits.
@AdamR28 Do you think you can get it to 200bhp per ton?
Good to see you are committed to some proper craziness! Carry on good sir.
If you ever come down south for a track day, I want to have a ride!
He'd need to get the weight to 690kg and that's if the car still makes 138bhp.
Both doubtful IMHO but worth a try.
Thanks
@shnazzle and
@Chilli Girl !
Quote from: iffyT on October 5, 2020, 22:57Yep, Ke=MV^2.
Doing some lightening improves everything. Whereas adding power only improves one thing, while increasing wear and tear to other bits.
@AdamR28 Do you think you can get it to 200bhp per ton?
Good to see you are committed to some proper craziness! Carry on good sir.
If you ever come down south for a track day, I want to have a ride!
Exactly - weight reduction every single time 8)
I've tried heavier, higher powered cars on track and they just feel... dead. And I'm a tight northerner, all that wasted fuel, tyres and brakes when you could go just as fast for a lot cheaper :))
200bhp/ton... I think it's doable. I have an aftermarket manifold on there already, plus will de-cat the link pipe, maybe build a proper collector if the standard one looks crap when I inspect it, and build a much less restrictive backbox (a bit like the Malain 'Race' one, except probably exiting straight out the back). That's gotta make 145bhp, maybe 150 on a good day, looking at this post and the one below: https://www.mr2roc.org/forum/index.php?topic=27521.msg488501#msg488501
At 145bhp, that means a requirement for 725kg. Again, might fall short of the 'target' but it'll be fun trying!
You would be most welcome to a ride
@iffyT - same goes for anyone. As with the Munter, the car is designed to be shared and enjoyed by as many as possible. At last count, Munter 1 had over a dozen different drivers on track, so the plan is to beat this with MunteR2 ;D
Have a few deliveries due this week, so will keep updating as and when things happen.
Sorry mate you'll be lucky if she cranks out the factory 138.
Nobody ever does before and after dynos so we never really know.
Good luck with the weight saving hope you don't need to go on a diet like me.
Looking like a very interesting project Adam. Even if you don't make 200hp/ton it will still be a beast. I'll be defo taking some tips on weight reduction from your build.
Don't suppose you have a spare front undertray from Mr poo mk1 do you?
I don't Phil, sorry, he came without out!
Quote from: 1979scotte on October 6, 2020, 13:08Sorry mate you'll be lucky if she cranks out the factory 138.
Nobody ever does before and after dynos so we never really know.
Good luck with the weight saving hope you don't need to go on a diet like me.
Fair shout! Maybe I'll chuck her on the local 'Heartbreak Dyno' at some point just for a laugh.
Haha. Thanks. Its good point you raise, there's usually a few kilos to come off the driver too!
Quote from: AdamR28 on October 6, 2020, 14:50Quote from: 1979scotte on October 6, 2020, 13:08Sorry mate you'll be lucky if she cranks out the factory 138.
Nobody ever does before and after dynos so we never really know.
Good luck with the weight saving hope you don't need to go on a diet like me.
Fair shout! Maybe I'll chuck her on the local 'Heartbreak Dyno' at some point just for a laugh.
Haha. Thanks. Its good point you raise, there's usually a few kilos to come off the driver too!
Always make we think of bikers spending £££on carbon fibre bits for their R1s when they could easily loose 10kg off their waste line.
At 105kg I could to with loosing 20.
Quote from: AdamR28 on October 6, 2020, 14:49I don't Phil, sorry, he came without out!
No problem mate.
Managed a few hours this afternoon dissecting Mr Poo. This is a very well put together car; logical, nice quality, well thought-out.
Or was.
20201006_165828.jpg
20201006_165420.jpg
The sheer amount of stuff that comes out of a car when you strip it is mental. Looking at the pile I sort of can't believe it all came out of that small space!
Removed so far, with either accurate or estimated weights (denoted by a c.)...
Seats and runners: 34kg
Doors: 56kg (!)
Dash with airbag: 10kg
Roof and associated gubbins: 22kg
Battery: 11kg
Heater matrix, controls, etc: c.5kg
Carpets and other plastics: c.5kg
Handbrake lever, seat belts, other misc crap: c.3kg
Skin of just one knuckle, surprisingly: 1g
Still to come out / off:
Windscreen and frame
Wiper motor, washer pump, bottle
Cooling fans
ABS pump
Handbrake cables
Main cat (replaced with a straight pipe)
A good lump of rear bumper
Maybe 35kg for this lot?
To go back in:
Roll cage: c.25kg
Seats, a runner, and harnesses: c.16kg
Shifter: c.1kg
Door skins, bolted into place: c.6kg
Battery: sub 1kg
All that totted up makes 181kg coming out, and 48kg going back. With a starting weight of approx 935kg, its gonna be a close call as to whether the final number starts with a 7 or an 8...
Quote from: AdamR28 on October 6, 2020, 09:31At 145bhp, that means a requirement for 725kg. Again, might fall short of the 'target' but it'll be fun trying!
Massive brain fart right there. Just squeezing into the 700s is nothing like low 700s, ha. So I can knock 200bhp/ton on the head right away.
Perhaps 2ZZ swap category is more likely. What do they (realistically) make, 180? And perhaps a ton and a bit if its a FL car with the added bracing, bigger wheels, chunky track tyres, a roll bar, and not much stripped out?
140bhp and 800kg would be bang on 175bhp/ton... new target :)
Screen is about 9kg, surround around 8kg - less than I thought!
20201007_072513.jpg
Frame is reasonably well reinforced...
20201007_072433.jpg
I'll weld a plate over to cap this off, then affix the front facing roll cage / bar struts to said plate. That bit of tube runs down towards the wheel arch so I'm going to assume its structural.
Had a little win with the washer bottle, it was completely full, so a very easy 4kg saved there ;D
Eeek no messing about there Adam, good job so far and look forward to further progress :D
A bit too gung-ho, it seems...
Thought I could dice with death and strip the immobiliser out, turns out I was wrong. Anyone on here got experience with it? I have all the bits that came out and think I've found all the areas it's spliced into the main loom(s), but a few of the wires are the same colours / thicknesses... I'm such a div.
In other news, had a few bits arrive including an IKEA roll cage:
20201009_105850.jpg
He's also now on a set of dollies to help shunting around.
20201009_161528.jpg
Exhaust is off ready for making a new one, backbox is 13kg and downpipe with car 8kg!
Quote from: AdamR28 on October 7, 2020, 04:37Quote from: AdamR28 on October 6, 2020, 09:31At 145bhp, that means a requirement for 725kg. Again, might fall short of the 'target' but it'll be fun trying!
Massive brain fart right there. Just squeezing into the 700s is nothing like low 700s, ha. So I can knock 200bhp/ton on the head right away.
Perhaps 2ZZ swap category is more likely. What do they (realistically) make, 180? And perhaps a ton and a bit if its a FL car with the added bracing, bigger wheels, chunky track tyres, a roll bar, and not much stripped out?
140bhp and 800kg would be bang on 175bhp/ton... new target :)
I reckon my FL is around 1050kg with 6 point cage, fully braced, 2ZZ engine (heavier than 1ZZ?) etc
No idea what power mine puts out. Very similar straight line speed to my mates 220hp ep3 which weights around 1220kg part stripped so 180hp/ton
With that I'd guessing mine is pushing out the standard 190hp with the BCM CDA intake with cold air feed to the side scoop, custom header, sports cat and custom free flowing backbox.
190hp - 1050kg =180hp/ton.
Nice one Phil, good to know!
Mr Poo lives again ;D
Though maybe not what you'd expect... huge thanks to
@Maurici for his moral support and brain power today. We spent about 4 hours digging through looms, trying to scope out wiring diagrams, tried reattaching all the stuff I'd ripped out after upending the bin, still nothing. Immobiliser wouldn't turn off :-\
20201011_150732.jpg
A mate who is an auto spark had popped round earlier, he'd dug out some full wiring diagrams and sent them over, so I gave him a quick call... his recommendation was to trace / check continuity from the ECU to the black fob reader thing around the ignition barrel. Which we tried, but the wiring colours didn't match. Odd.
But, the wiring colours did match another plug in a very similar location.
20201011_150710.jpg
See those two little white 5 pin badboys there? I've never seen two plugs the same so close together on a car wiring loom before, and yep, I had put them back in the wrong places.
Fired up perfectly after that :))
So I feel like a bit of a muppet, but a huge lesson learned and relieved I can now crack on with the rest of the build - which will involve as little electrical stuff as possible!
Had a couple of hours more tinkering this morning before work...
Did some exhaust calculations. I figure the engine won't spend much of its time below 4 or 4.5k rpm now, so a 4-1 design will be better. 38mm primaries, 50mm for the rest. That's enough to efficiently flow ~150bhp with decent manufacture. I won't be going quite 'to town' like I did with the last one I made:
lobs.jpg
But will at least try to make it neat, tidy, light and functional. Something along these lines:
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Currently trying to get my hands on a cheap / free manifold so I can reuse the header flange (having given one away the other week, arse) - if anyone has anything please let me know! Could perhaps do a deal / swap with the eBay header I have on there at the moment.
Figured now as a good time to make some engine inlet side access...
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And knocked up a cover out of old exhaust heatshield. Needs tidying and some foam at the back to seal, but will do the job.
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More re-purposing - I designed, collected all the bits for, and started on a scratch-built single seater bike engine car a few years ago:
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Then my wife at the time decided she'd like to go and sleep with someone else without informing me, life got a bit hectic, and that got canned. So I've been looking for a way to re-use this for a while...
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Chop saw came out, and Mr Poo now has the beginnings of a cage. I will of course upgrade the gaffer tape to weld at some point.
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Looks high but I want to make sure the below MSA regulation is met - I can't see myself doing an MSA event (or one of the fussy scrutineers letting such a creation take part), but from a 'makes sense' point of view I'd like to have good clearance for taller drivers than myself.
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@AdamR28 No chance for grass to grow under your feet! Thank you for the pictures, I particularly like the one with the super tool box and the juxtaposition of the two Birmingham screwdrivers.
I think ive still got my stock manifold in the loft will have a look for you..
Quote from: Joesson on October 12, 2020, 11:39@AdamR28
No chance for grass to grow under your feet! Thank you for the pictures, I particularly like the one with the super tool box and the juxtaposition of the two Birmingham screwdrivers.
Ha! You've got a keen eye. I was battering the shell flat t omake way for the spreader plates, and the smaller one just wasn't man enough!
Quote from: thetyrant on October 12, 2020, 11:54I think ive still got my stock manifold in the loft will have a look for you..
Amazing, thanks man. Swapsies for a pair of wheels?
Quote from: AdamR28 on October 12, 2020, 12:03Amazing, thanks man. Swapsies for a pair of wheels?
Is it just the flange to head you need ? i was possibly going to reuse the flange to cat pipe on my turbo build for inital mock up so i can cut other one off for you, that is of course if i didnt the whole thing when i moved house end of last year, but dont think i did!
Yeah that's all I'm after, if you do have it then please let me know if you want owt for the flange! (Oooh err missus)
Similarly if I can get hold of a cheap manifold and you still need the bottom flange, you're welcome to it once I've robbed the top one.
Quote from: AdamR28 on October 12, 2020, 13:34Yeah that's all I'm after, if you do have it then please let me know if you want owt for the flange! (Oooh err missus)
Similarly if I can get hold of a cheap manifold and you still need the bottom flange, you're welcome to it once I've robbed the top one.
Had a root about in garage loft at lunchtime and all i could find was 2 old cat pipes :( looks like i might of chucked the manifold when i moved DOH! although will check my overspill storage which is at my parents when im there at the weekend.
I've sourced one Ian, will lop the header flange off and you're welcome to the rest 8)
Had a couple more hours this morning before work - insomnia does have benefits sometimes!
Employed Mr Guillotine and Mr Folder to make the spreader plates. Always feels a bit like taking a gun to a knife fight using these, but it does such a neat job so easily I really can't complain.
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Chose this location for a few reasons:
- It's a big box structure that runs the whole width of the car, much more sturdy than the floow pan
- Being enclosed, there's no fuel tank or stinky melting underseal to worry about
- The OE seatbelts mount here, this is usually a good clue as to where the manufacturer built strength into the shell
- It's double skinned, meaning you can melt some proper volumes of metal rather than having to daintily tack into some 0.8mm (minus whatever nearly 20 years of rust deducted) wafer thin stuff
I call this 'tack n smack' - a bit like 'shake n vac' but a little warmer. Basically stick a corner or a side down, then use the Birmingham Screwdriver to form the plate to whatever it's being stuck to, tacking as you go.
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It was at this point (too late) I remembered how much of a mess any paint or seam sealer makes when trying to weld to / through it. I am confident this isn't going anywhere, but it sure doesn't look pretty!
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Fixed for the other side...
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Same technique for the back stays. Again finding an area of 'enclosed box' to pick up onto. Turns out it is also pretty thick, apart from the very bottom which blew through immediately and I had to turn the welder right down!
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Bashed the main hoop together and chopped it ready to fit the spreader plates...
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Welded it in - more tack n smack!
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First backstay in
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The welder is a little flattering, but happy with the results welding on fresh, clean, 'proper' material.
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Then the welding wire ran out. I need to pop to the supplies place for a new regulator for the TIG after tha exploded the other week (!), so perhaps I can get the other backstay in later today, it's already cut and profiled ready to stick in.
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Check out that ride height! :)) I can see why you chopped your springs now
@Petrus - what weight are you down to?
Quote from: AdamR28 on October 13, 2020, 09:29Basically stick a corner or a side down, then use the Birmingham Screwdriver to form the plate to whatever it's being stuck to, tacking as you go.
Had to google "Birmingham Screwdriver" :D Impressive work!
Ha. Just trying to make things more understandable for
@Joesson ;)
Managed to get the required supplies, rear part of the cage is now done!
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Seat fitting next, so I can figure out where the harness bar can go. I would normally stick it in the main hoop, but I think the seat will be right back there, so won't clear. Plans B and C are to put it between the rear supports, or straight into the shell. So we'll see.
Once the seat is in, I can get the steering wheel in the right position (will make a new column, the OE one is unbelievably heavy!), then get the front supports and side bars in. Don't want to do it in the other order as access gets poor once the side bars are in!
Seats in - a lot easier than expected. Perhaps I got lucky, perhaps I'm just getting better at it. Used to be a job I hated but this was enjoyable for once.
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Looks like I will just get away with sticking the harness bar directly to the back of the main hoop - which will also give a bonus advantage that I can add a 5th mounting point somewhere around shoulder height on the seat. I've had GRP seats crack before, and the nuts pull out of the bases, when used on track.
The harness bar might have to be a bit cockeyed though to match up to the shoulder strap holes in the seats! The passenger is of course as low down as I could get it, but I needed to raise the driver's seat away from the floor pan a little so I can see over the front successfully.
Also had a hunch the top steering UJ could be flipped over and it'd fit the rack... that is indeed the case, so I can bin off the old rusty one that has play, and still use an OE quality UJ. Winning. I'll just run one UJ straight from rack to wheel. I appreciate the two UJ thing is partly for wheel adjustment and partly to allow it to collapse, but I think if I have a head on big enough to move the whole front end of the car back 2 feet and the steering wheel back a further two, I'll have bigger things to worry about...
@AdamR28 Good progress and with such a sparsity of tools in evidence of use. Probably best to keep any passenger down where they can't see where their going!
Thanks - it is amazing what the old knocking stick can do, isn't it!
Bit more bodging... Existing lower column chopped up, turned down, smacked into and stuck onto a bit of 11/16" CDS to make a new column. Upper UJ swapped to the bottom and flipped over.
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Old bicycle headset cup and bearing, top wedge, and turned down bit of broken steerer tube used to make a clamp / wedge / locating thingy for the column. The headset cup will be affixed in the 'right' (depending on where I want the wheel) place by welding it to some tubing off the dash brace bar. A bit OTT but ergonomics and controls are my 'thing', especially for circuit cars.
This design - combined with the 'flat' on the OE splined section, allows a bit of in and out adjustment to the wheel too, handy as I may tweak the seat a bit more vertical at some point to give a better view (the driver's seat mounts are designed so that I can space the seat up and down at the rear).
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Steering wheel boss in the makings - no that's not a drawing of a wankel rotor, but I amused myself after having drawn it so decided to grab a snap.
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"Only 3 bolts!" I hear you cry. A mate who works at BAE reliably informs me that they drag F-16s around using 4x M5 bolts in shear, so I think 3 of 'em will be enough to rotate Mr Poo's steering rack.
Stock steering setup is suprisingly heavy, so this should take a few kilos off as well as putting the wheel in a more suitable place for the new seating position.
Neat usage of the available UJ, that looks to be in good condition, unlike
the PS pipes, but I guess those are extra to requirements. Top tip, you may want to use a different screw driver when you start on them.
PS: Is your mate @BAE likely to be a passenger?
Yeah the PAS is already deleted, just looped the free lines. I may do it properly sometime if I can be bothered!
It is very likely John will be a passenger at some point yeah, so it'll be his fault if I disappear off into the nearest tyre wall ;D
In related news... Happy with how the cage has turned out, all for under £100 (plus a bit of my time!).
Got a bit of my welding mojo back a bit... it had been a while and I was clearly out of practice.
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Side impact bars have a subtle curve so they are under compression in a side impact.
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Also sorted the steering wheel mount, looks really weird but is stiff enough, and the driving position is poifik which is what matters 8)
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Happy bunny!
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Progress may slow now for a few weeks as I have a new staff member starting at work, and we're starting to get Xmas deliveries in...
that looks like it's going to be a right thing!!
Are they going to allow that on track?
You'll scare the other punters.
Fascinating to see a skeleton 2. Never seen it like that before. :o
Quote from: tets on October 16, 2020, 18:03that looks like it's going to be a right thing!!
A right mess maybe!
Quote from: 1979scotte on October 16, 2020, 18:53Are they going to allow that on track?
You'll scare the other punters.
I hope so. Plan is to build some sort of 'bumpers' around the wheels so they're not open...
Quote from: Chilli Girl on October 16, 2020, 19:23Fascinating to see a skeleton 2. Never seen it like that before. :o
They are quite interesting eh? I've seen one or two MR2 'karts' on the web, it's more common with MX5s though.
In the quest for cheap speed, I went on the hunt for smaller wheels. This will drop the centre of gravity without upsetting the suspension design, and effectively reduce the gearing which is the same as adding poowwweeerrrr. 10% in fact, if I could shoehorn some 195/45/14s on there as opposed to the stock 205/50/15s. Not insignificant...
I have a set of 13s that actually JUST fit, but they are worth as much as the car and probably too light, so not really appropriate sadly.
So, that led me to Facebook classifieds, and a set of unloved MX5s wheels a couple of miles away. All 4 tyres knackered, but the wheels actually in pretty good nick, 14" and only £50, so worth a punt. Armed with a tape measure, I had a check of the inner bore and thought they might clear - worth a punt anyway, and deal with any problems later ;D
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Picking them up revealed a funny smell. I have a suspicion the previous owner's dog had been using the stack as a pissing post! Still, a quick wash sorted that, then time for the moment of truth...
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They only bloody fit! Literally a mil to spare. I had to pull the wheel weights off to get the rears to go round, and even then the sticky residue scrubs the caliper!
Now on the lookout for tyres, not much choice in that size and all road tyres (which is what I wanted), so good value, fun in the dry, and safe in the wet.
Quote from: AdamR28 on October 19, 2020, 18:34Quote from: tets on October 16, 2020, 18:03that looks like it's going to be a right thing!!
A right mess maybe!
Quote from: 1979scotte on October 16, 2020, 18:53Are they going to allow that on track?
You'll scare the other punters.
I hope so. Plan is to build some sort of 'bumpers' around the wheels so they're not open...
Quote from: Chilli Girl on October 16, 2020, 19:23Fascinating to see a skeleton 2. Never seen it like that before. :o
They are quite interesting eh? I've seen one or two MR2 'karts' on the web, it's more common with MX5s though.
In the quest for cheap speed, I went on the hunt for smaller wheels. This will drop the centre of gravity without upsetting the suspension design, and effectively reduce the gearing which is the same as adding poowwweeerrrr. 10% in fact, if I could shoehorn some 195/45/14s on there as opposed to the stock 205/50/15s. Not insignificant...
I have a set of 13s that actually JUST fit, but they are worth as much as the car and probably too light, so not really appropriate sadly.
So, that led me to Facebook classifieds, and a set of unloved MX5s wheels a couple of miles away. All 4 tyres knackered, but the wheels actually in pretty good nick, 14" and only £50, so worth a punt. Armed with a tape measure, I had a check of the inner bore and thought they might clear - worth a punt anyway, and deal with any problems later ;D
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Picking them up revealed a funny smell. I have a suspicion the previous owner's dog had been using the stack as a pissing post! Still, a quick wash sorted that, then time for the moment of truth...
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They only bloody fit! Literally a mil to spare. I had to pull the wheel weights off to get the rears to go round, and even then the sticky residue scrubs the caliper!
Now on the lookout for tyres, not much choice in that size and all road tyres (which is what I wanted), so good value, fun in the dry, and safe in the wet.
Very interesting re the 14s fitting. What offset are the mx 'pissy' wheels?
Brimful of asha, I believe, same as the MR2 ones.
Weirdly, I can't find the ones I've bought in this list. Perhaps the UK spec wheels were different: http://www.jason-parker.net/images/wheels.htm
How would lowering the car to suit the 14" wheel affect things like driveshalt angles, control arms etc?
Going from 205/50/15ss to 195/45/14s: The car literally goes down by 1", with everything as it is (smaller tyres are half an inch reduction in radius, the wheels are another half an inch).
90mph at the limiter in 3rd gear becomes ~80mph, etc.
The point is that you don't have to lower the suspension (which upsets driveshaft angles, roll centres, etc), you simply lower the car as a whole.
On the power side of things...
Take 100Nm at the engine, going through 4th gear (1:1 ratio) and into a 4:1 diff (rounded numbers for ease), that gives 400Nm at the hubs.
A 205/50/15 tyre with radius 294mm therefore produces 1360N of forwards thrust at the tyre contact patch (torque = force x distance, rearranged).
A 195/45/14 tyre with radius 265mm provides 1509N - an increase of just over 10%.
The other way to do it would be to add ~15bhp to the engine, which is much more invasive and expensive!
Ideally I wanted 175/50/13s (ran these before on mx-engineinwrongplace - AR1s) - that would have given 1587N / 17% - but not worth the cost here.
Quote from: AdamR28 on October 20, 2020, 08:44Going from 205/50/15ss to 195/45/14s: The car literally goes down by 1", with everything as it is (smaller tyres are half an inch reduction in radius, the wheels are another half an inch).
90mph at the limiter in 3rd gear becomes ~80mph, etc.
The point is that you don't have to lower the suspension (which upsets driveshaft angles, roll centres, etc), you simply lower the car as a whole.
On the power side of things...
Take 100Nm at the engine, going through 4th gear (1:1 ratio) and into a 4:1 diff (rounded numbers for ease), that gives 400Nm at the hubs.
A 205/50/15 tyre with radius 294mm therefore produces 1360N of forwards thrust at the tyre contact patch (torque = force x distance, rearranged).
A 195/45/14 tyre with radius 265mm provides 1509N - an increase of just over 10%.
The other way to do it would be to add ~15bhp to the engine, which is much more invasive and expensive!
Ideally I wanted 175/50/13s (ran these before on mx-engineinwrongplace - AR1s) - that would have given 1587N / 17% - but not worth the cost here.
Good explanation. So i'd have to keep the ride height near stock and have the monster trucking look with big arch gaps. Suppose it would only be for track as I's use FL 15/16 for road.
Haha. Yeah good point on the arch gap thing. It's not something in my considerations at all but appreciate others don't want the 'off roader' look!
Looks like you will need a flame throwing guitar player chained onto the front!
https://www.youtube.com/watch?v=hRF-pgMWpwQ&ab_channel=AmiratheEccuyah
Got any plans to paint it?
Yeehaa, are you offering? :D
Nah, paint is too heavy. Rust is much lighter.
Quote from: AdamR28 on October 20, 2020, 15:33Yeehaa, are you offering? :D
Nah, paint is too heavy. Rust is much lighter.
That is not too bad a look to get around in London traffic. In the 80's I occasionally was asked to drive the Company's delivery flat bed transit, that was driven by all and sundry and looked decidedly the worse for wear, and it is surprising how gaps open up in traffic when you point the front end at too small a gap.
Only those that have driven in London will appreciate the validity of that.
I think a brushed on paint job using rustoleum combicolour would tie it all together.....
Quote from: Topdownman on October 20, 2020, 17:43I think a brushed on paint job using rustoleum combicolour would tie it all together.....
A small foam roller and Rustoleum made our garden railings look young again, goes on over bare metal, existing paint (and rust according to the manufacturer, but I did get most of that off) and has stayed there for for around 18 months in hot sun and freezing cold and all points in between.
I painted my old T4 van with it and put white primer on first with a roller. It left air bubbles in it though so I rubbed it down then switched to a brush for the top coat.
I always did regret leaving it in the primer as it looked like a golf ball with a slight rubbing down!
(As well as looking cool, it would have been very aerodynamic too...).
Strange, a roller typically suits a larger surface and a brush a smaller surface, but I found that the brush was going to take forever on the 12 mm bars and the roller really speeded up the process.
All this talk of paint... get out of my thread :))
Seriously though, I completely agree on the merit of a banger. I'm currently also blasting around in a knackered old K11 Micra - can literally park it anywhere without worry, doors left open, nobody will go near it!
Bit of brake progress this morning - ripped all the pointless stone guards off (they were so rusty I did literally rip them off), pulled the servo and ABS out (about 5kg's worth).
Did some brake calculations (http://www.brakepower.com):
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Just need to modify the pedal box a little to increase the leverage of the pedal itself, and I'll find a way to use the standard master cylinder. Normally the master would sit centrally between those 4 holes, and those 4 holes are used to mount the servo.
I had eyeballed the spacing of the servo last night, and it looked similar to the master...
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Bingo!
Just a bit of chopping to do, and the master can be bolted straight to the pedal assembly, with a new clevis pin hole redrilled a bit higher up, and a bit of 'relieving' of the firewall.
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Also ordered all the stuff to make a manifold, looking forward to getting cracking with that! Figured either one of these two will be the easiest way to do it, and I can probably get away with just 8x 90 degree bends, 'manipulating' the tubing a little to get it to all fit and maintain matched header lengths.
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Snooping Spyderchat it appears this design should free up a fairly significant amount of power, especially in the 6-7k rpm range:
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Not sure if that's stock vs long 4-1 headers, or some sort of aftermarket vs the new header, but either way if I can have some fun playing with the welder and improve bhp/ton in the process, happy days.
I like your thinking on the brake master cylinder and pedal connection, seem to remember that arrangement.
Not to mention the manifold. If you jig it up you could start a side line supplying them.
Impressed with the work rate!
Some doods in the states stripped a Corvette to the tub similarly to your MunteR2:
https://youtu.be/Nt-JPcFM_Qg (Warning, they are very American, a lot of burnouts, drag racin', and whoopin' and hollerin! But their engineering is solid)
They managed to get theirs down to 2550lbs (1150kg) from 3200lbs (1450kg) or a 20% drop, with roll hoop and harnesses etc. So I would say your weight target is certainly achievable considering on the 'vette, the core components would be a larger mass fraction due the fibreglass bodywork.
Also, are you going to shave those calipers?! That's some tight clearance! Especially when you add in a load of heat on track.
Shine on brother, great progress
Haha, thanks
@iffyT ;D
Leroy looks funny. Chassis must be like a wet noodle! Impressive to get so much weight out though.
On the sly, my new target has been 750kg for a while now... having removed all the panels, and checked what weights they are, I think that's another 50kg come off. A few other bits I didn't account for originally, related to the bodywork, have added up to a few kg too. We'll see soon enough!
Calipers... I'm not sure. It is awfully close. I think I'll blast around the industrial estate here and see what it's like, any rubbing will be obvious. There is plenty of meat on the calipers though, so skimming a mil or so off with the flap disc won't be an issue.
Brake pedal is also now back in, everything lines up nicely. Still have a bit of adjusting to do of the brake light switch and clevis once the brakes are bled up, but access is good.
New push rod made from an MX-5 suspension bolt, with the end rounded off into a ball by sticking it into the drill and flap disc-ing the end down.
Also found an old MTB dropper seatpost rubber boot which was the perfect size to go over the master and keep water out - normally it's hidden away inside the servo!
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Like a glove 8) Only had to enlarge the hole slightly, the shape of the master and reservoir fit around that join in the shell panels perfectly.
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Quote from: AdamR28 on October 21, 2020, 15:24Leroy looks funny. Chassis must be like a wet noodle! Impressive to get so much weight out though.
That wet noodle now has 1500bhp+ and runs 7s... It must be quite a ride!
They seem to know how to build stuff (unlike a lot of youtubers) as they've done several hundred drag runs and the engine has never needed to come out (so they say).
I'm sure they had to add a load of buttressing, backing plates etc all over that chassis which would have added weight. Although tbf the C5 Corvette lends itself well to this as it's essentially an old school body-on-frame, crossed with some build elements in common with space-frame race cars. It's fairly stiff.
Ah! I didn't know about any subsequent development, just watched a bit of the video you linked to; sounds like it's come on leaps and bounds then. One to stick on my to-watch list - thanks!
Koni inserts fitted this morning, ready to go back on with a set of almost-new 2nd hand Tein springs. I think these are going to need cutting down - the front of the car is nearly 2" higher than stock ride height due to all the weight that's been taken out!
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This is a pretty straightforward job, you just have to be brave and go for it - but obviously remember you can take off, but not put back on easily...
It's a good job I'm a man and ignored the instructions... my rears came with paperwork for the fronts! It said to cut 65mm off, which would have left me pretty snookered.
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In the end, about 30mm was cut off the rear, compared with 65mm ish at the front.
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If anyone stumbles across this and is about to partake on fitting a set of their own, feel free to give me a shout for a confidence booster / tips.
Good choice of suspension same as i have :), with your lower weight the spring rate should be ok as i find it a bit soft for me on my full weight car on track, be interesting to see ride height as again i think its a bit low on my car for bumpy back road hooning anyhows :D
Yeah man, I think the Koni Sports are an excellent damper - have had them on another car before, also with lowering springs. I rate them as kind of 'OE Plus', a quality unit with proper damping curves, rather than far eastern anodised bling which looks pretty but doesn't allow the wheels to move up and down properly!
I measured ride height on standard springs / wheels at 155mm front and rear from the ground to bottom of sill pinch weld, so obviously that will put a standard car at around 125mm on -30 lowering springs.
I figure I'm dropping 25mm from the smaller wheels / tyres, making 130mm ride height, then if the suspension is lowered a smidge on top of that to get to 115mm ish, that's a good place to be for track only use - hopefully meaning I won't be running into the bump stops all the time. That said, the NA Miata is designed to run on the bump stops in full lateral loading, so I won't be disappointed if that happens.
Shocks back on and onto the floor at lunchtime. Ride height approx 160mm as it stands but that's with stock sized wheels / tyres, so it is effectively 135mm at the moment. Higher than standard even on -30mm lowering springs - it must be light, ha!
There is plenty of travel left before the bump stops, about 35mm up front and 50mm at the rear (on the damper - therefore a touch more at the wheel), so with that in mind I'll chop a coil off the top of each spring. The top couple of turns sit coilbound so this is completely safe. After that, I'll let them settle and see where its at - likely 120mm ish, which will leave the rear lower wishbones parallel with each other and the floor, perfecto!
Nice work on the Konis! I'm in the process of doing the same, but I've hit a snag... cross-threaded one of the retaining nuts and I'm in the process of helicoil repairing it. Sadly I don't think it's worked. I might need the help of someone more experienced :(
Would love to hear how your feedback on them when you've had a chance to road test.
P.S. did you trim the front bump stops? My understanding is that's what most here do when using any lowering springs.
Oh bummer. Do you mean the lump welded into the bottom of the damper? Fairly sure that will be repairable - where are you located?
That was one of my 'tips' - those lumps aren't central on the damper (manufacturing tolerance), the clue is in the fact they get you to drill a 14mm hole in the original shock body for a 10mm bolt... If you rotate the damper, you will find a spot where it lines up better with the hole you've drilled, reducing the chance of cross-threading.
I haven't trimmed the bump stops, and don't plan to, but yes that's what most people do.
Ikea manifold is all here, about £300 and 11kg's worth. Tons lighter than the standard setup (which is approx 28kg) and should flow better too.
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In further suspension news, it hasn't sagged any more overnight, so I'll crack on with chopping a coil off each spring later.
Checked the wheel frequency, around 2.3Hz front and 2.4Hz rear. A bit higher than my preference of 2Hz, but it has a good ratio (rear higher than front by ~5%) and should work well with the road tyres.
Quote from: AdamR28 on October 23, 2020, 09:30Oh bummer. Do you mean the lump welded into the bottom of the damper? Fairly sure that will be repairable - where are you located?
That was one of my 'tips' - those lumps aren't central on the damper (manufacturing tolerance), the clue is in the fact they get you to drill a 14mm hole in the original shock body for a 10mm bolt... If you rotate the damper, you will find a spot where it lines up better with the hole you've drilled, reducing the chance of cross-threading.
I haven't trimmed the bump stops, and don't plan to, but yes that's what most people do.
Yep, it's the bolt at the bottom. It's a 25mm M12x1.5 and as you say the hole is a 14mm one. I actually widened my hole with a file as it wasn't exactly central.
I think what's caused the crossthreading is that the damper wasn't being pulled into the strut by my tightening of the bolt. I've tried a rubber mallet to help it home but it just won't go. It's in past the securing nubs but about 5mm shy of being fully in. The other 3 were fine.
I'm now searching for a new bolt because I'm worried if I try to hard with the current one, I'll strip the helicoil insert.
I suspect also, like me, you found that on the fronts, you have to cut enough off to fit the damper in, the width being tapered at the top, such that the rubber dust boot isn't quite big enough?
Everything was going well until I noticed one of the fronts was taller than the other ... super glad I noticed that before putting a spring on or fitting it to the car!
Yeah the front boots aren't long enough at all, I'll still fit them to stop water getting inside the existing damper tube though, in the hope of preventing a future seizure!
If you get stuck for a bolt let me know and I'll have a rummage, may have something. The other option is to effectively use a stud and a nut (only on the rear though, don't think there will be enough space up front due to ARB drop link proximity) - that should ease pressure on the female thread in the damper helicoil.
Quote from: AdamR28 on October 23, 2020, 09:46Yeah the front boots aren't long enough at all, I'll still fit them to stop water getting inside the existing damper tube though, in the hope of preventing a future seizure!
If you get stuck for a bolt let me know and I'll have a rummage, may have something. The other option is to effectively use a stud and a nut (only on the rear though, don't think there will be enough space up front due to ARB drop link proximity) - that should ease pressure on the female thread in the damper helicoil.
Thanks Adam, I might take you up on that if my search draws a blank! I'll look into the stud idea, could be a winner if I can get the damn damper seated properly!
My plan with the short boots was to supplement them with some good old gorilla (duct) tape. Crude, I know, but it is waterproof and should do the job.
Little bit of exhaust mocking up / calculating at lunch...
Looks like it should all fit pretty nicely.
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headers.jpg
And to put a more visual representation on that...
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Been beavering away at the manifold this afternoon.. had a slight 'issue' with the right hand driveshaft though. In that it would have been in the way! :))
That meant a redesign, and chopping half of the 90 degree bends to a 75 degree angle.
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Tough going, just 4 cuts wore out a new hacksaw blade!
Straight cuts done with a tubing cutter, makes light work and ensures they are square.
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Then tidied up on the belt sander.
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Starting to come together...
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And in situ checking the collector clears the subframe.
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And here's how it sits now, ready for tacking up!
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Number 3 a Little longer straight out of the head, as it has a shorter route to the collector...
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Close enough at the header flange. I'll chop these to fit, then weld to the flange and die grind smooth, once I've fuly welded up each primary individually. Will back purge them and use the pulse setting without filler, this gives a lovely result (again the welder flatters my skills!).
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That, sir, is a lovely manifold. DIY PPE mani
That's a tidy looking manifold! Can't wait to see it all welded up. I'd love a longer runner 421 one day... only one guy I'd use though and he is a busy boy!
Keep up the good work 👍🏻
Thanks gents!
I've been trying to find this via Google but no joy... what does PPE stand for? I've seen the term loads of times and initially assumed it was a brand, but seems not. Something Performance Exhaust, perhaps?
Made a bit more progress before work today.
Did a test weld on some offcuts, ground it back and bashed it up, etc.
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Welding at 55 amps with pulse, it hasn't fully penetrated but seems plenty strong enough and no sugaring at the back, so I may not even need to bother back-purging. I probably will though as having put this much work in it'd be a shame to cut a last-minute corner!
Fit up is really good after using the sander, literally zero gap when held up to a light.
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Hoping to have it fully manifold shaped by the end of lunch...
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Quote from: AdamR28 on October 26, 2020, 09:49Thanks gents!
I've been trying to find this via Google but no joy... what does PPE stand for? I've seen the term loads of times and initially assumed it was a brand, but seems not. Something Performance Exhaust, perhaps?
Made a bit more progress before work today.
Currently PPE is viral! : Personal Protective Equipment.
Been around in industry for many years.
What does a PPE exhaust protect you from though? Being burned off at the lights by a 1.9TDi Golf?
PPE in MR2 world is a brand from america PPE engineering who make (or used to make? not sure which) exhausts/headers etc for our cars :D
see here - https://midshipgarage.com/products/ppe-engineering-toyota-mr2-spyder-zzw30-00-05-4-1-2zz-race-header?variant=12114741395576
Thanks Ian - I thought that, but I see the term banded about so much about headers / manifolds that aren't manufactured by PPE I got confused! I guess people mean 'manifold made to look like a PPE' etc.
Quote from: AdamR28 on October 26, 2020, 10:31Thanks Ian - I thought that, but I see the term banded about so much about headers / manifolds that aren't manufactured by PPE I got confused! I guess people mean 'manifold made to look like a PPE' etc.
Yes i think it gets used as a general term for the 4-1 design manifolds :)
Quote from: AdamR28 on October 26, 2020, 10:31Thanks Ian - I thought that, but I see the term banded about so much about headers / manifolds that aren't manufactured by PPE I got confused! I guess people mean 'manifold made to look like a PPE' etc.
That's exactly the case.
Basically if it's equal length 4-1 going straight down, it's a PPE-esque manifold.
Although your runners seem to be a bit wider. So, curious how that works out.
What do you mean by 'wider' exactly?
The stock manifold uses 38mm diameter (OD) tubing, this is the same, and I'd have thought the (real!) PPE would also be the same - perhaps my eyes need calibrating!
Quote from: shnazzle on October 26, 2020, 13:57Basically if it's equal length 4-1 going straight down, it's a PPE-esque manifold.
Beejeezus... do americans réally have the collective memory span of two decades only?
Awesome work Adam.
Quote from: AdamR28 on October 26, 2020, 15:00What do you mean by 'wider' exactly?
The stock manifold uses 38mm diameter (OD) tubing, this is the same, and I'd have thought the (real!) PPE would also be the same - perhaps my eyes need calibrating!
Someone will likely correct me but I'm pretty certain the PPE has narrower runners to maintain torque lower down.
Aah, makes sense - thanks for the info!
1zz PPE header has 1.5"/38.1mm piping according to this - https://midshipgarage.com/products/ppe-engineering-toyota-mr2-spyder-mr-s-zzw30-mk3-1zz-header-manifold-high-flow-cat?_pos=5&_sid=2c91e1d08&_ss=r&variant=32412696805481
My previous link was the 2zz version now i look at it properly :)
I did think I'd seen 'proper' ones at 38mm when doing my research, and having that value coincide with my own sums led to that decision. Happy days, thanks again Ian!
A bit more metal chopping and sticking this morning.
Releasing the flange from the old manifold was easy, but getting the old bits of primary out was not! I think this took about 90 minutes in total, and a couple of grinding / flap discs, but well worth it as the OE flange is tons better than anything else - lighter, and a better shape with the pressed features helping to seal the gasket. (Number 2 done here, with the other 3 still to go).
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Number 3 is a bit 'long', so I'll chop a few mil off down at the collector to even things up if I can't shuffle it into position with the persuader.
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Test fit... like a glove.
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And the collector sits in a good place too, phew.
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Weight is a hair under 4kg for now, so perhaps a smidge over with the lambda bosses in. A very good saving over standard!
All the hard bit done now, can't wait to get the engine fired up again - perhaps a couple of days to do all the fiddly bits like springs, lambda bosses, etc.
Quote from: thetyrant on October 27, 2020, 07:251zz PPE header has 1.5"/38.1mm piping according to this - https://midshipgarage.com/products/ppe-engineering-toyota-mr2-spyder-mr-s-zzw30-mk3-1zz-header-manifold-high-flow-cat?_pos=5&_sid=2c91e1d08&_ss=r&variant=32412696805481
My previous link was the 2zz version now i look at it properly :)
I stand corrected! Thanks :)
Well, I think that's the manifold finished... ;D
I did back purge in the end.
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The welds came out a bit weird. Tried more gas, less gas, a bigger cup, absolutely scrupulous pre-cleaning, but they were just a bit 'slaggy'. Perhaps cheap material with impurities, I dunno.
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Fine with the top layer of crud removed though.
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Back purge worked nicely, no sugaring.
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Primaries all welded round. I was a bit out of practice to start with, but got better towards the end!
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Attacked with the die grinder to clean up.
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Et voila!
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It even fits, haha. Phew.
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Backbox should be fairly straightforward now, but I'll need to park this for a few days to tackle The Bucket, which has an MOT looming...
Quick lambda sensor question for those in the know:
- All 3 of them are the same, right? Just with different length leads?
- Do you need the final one?
Thanks in advance!
Good work :D yes all 3 lambdas are same just different length leads like you say, if you dont have the post cat one fitted you will get an EML for it, i think
@shnazzle found it also does play a small part in fuelling? but think bulk is the 2 in manifold and 3rd for checking cat efficiency etc...JDM cars dont have a 3rd one :)
Cheers Ian. I did a bit more reading and apparently the first two are the ones that do fuelling, the last one does bugger all in that respect - just checking for cat efficiency as you said.
During said research I also found out that if you decat then you need to run a spacer to get the 3rd sensor out of the airstream, else it'll throw a MIL.
Exhaust progress...
Mocking up
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Extender / spacer tube for the 3rd lambda sensor - 6mm hole to the exhaust tube, should be enough to let it sniff something without going haywire. Finally got my welding half decent at the very end of the project, just shows how much practice this sort of thing takes to be good at...
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Hanging around. I'll add another at the other end of the silencer, which will attach to a lighter version of the slam panel.
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Collector, slip on join, springs
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Went for the full Wacky Racers angle. Looks like it's sat really high, but I have used the OE exhaust mount which gives an idea where it sits in 'reality'
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Good ground clearance
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Already turned golden brown just from a quick run up!
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Sounds really quite good. Barely above standard at idle, and a nice smooth sound. Pretty raspy with a few more revs. I think it might be quite loud at full chat, but hopefully enough to get by at a track day. Worst case I can make an extra bolt on silencer setup pretty easily.
Engine management light isn't on despite all the fecking about I've done with the car, ECU unplugged, bits of loom removed, lambda sensors swapped around (for fitment reasons) etc, so fingers crossed it will stay that way!
Really happy with how it came out - and completely see how a proper custom exhaust can run to 4 figures. I think I've spent about 20 hours and £300 on bits, and while obviously the result isn't quite as good as the best exhaust fabricators such as CSK or Simpsons, I wouldn't be embarrassed to stick it next to a Zero, 'proper' PPE, or anything like that (from what I've seen on photos, anyway).
Next up... tidy up! What a bloody mess the workshop is now, tools and bits of grindings / filings everywhere :))
By Jove Adam.
That looks véry smooth indeed!
Cannot wait to read what you do with the suspension set up!!
Quote from: AdamR28 on October 30, 2020, 15:43Cheers Ian. I did a bit more reading and apparently the first two are the ones that do fuelling, the last one does bugger all in that respect - just checking for cat efficiency as you said.
During said research I also found out that if you decat then you need to run a spacer to get the 3rd sensor out of the airstream, else it'll throw a MIL.
Exhaust progress...
Mocking up
20201030_082600.jpg
Extender / spacer tube for the 3rd lambda sensor - 6mm hole to the exhaust tube, should be enough to let it sniff something without going haywire. Finally got my welding half decent at the very end of the project, just shows how much practice this sort of thing takes to be good at...
20201030_112547.jpg
Hanging around. I'll add another at the other end of the silencer, which will attach to a lighter version of the slam panel.
20201030_135651.jpg
Collector, slip on join, springs
20201030_135702.jpg
Went for the full Wacky Racers angle. Looks like it's sat really high, but I have used the OE exhaust mount which gives an idea where it sits in 'reality'
20201030_135718.jpg
Good ground clearance
20201030_135731.jpg
Already turned golden brown just from a quick run up!
20201030_145231.jpg
Sounds really quite good. Barely above standard at idle, and a nice smooth sound. Pretty raspy with a few more revs. I think it might be quite loud at full chat, but hopefully enough to get by at a track day. Worst case I can make an extra bolt on silencer setup pretty easily.
Engine management light isn't on despite all the fecking about I've done with the car, ECU unplugged, bits of loom removed, lambda sensors swapped around (for fitment reasons) etc, so fingers crossed it will stay that way!
Really happy with how it came out - and completely see how a proper custom exhaust can run to 4 figures. I think I've spent about 20 hours and £300 on bits, and while obviously the result isn't quite as good as the best exhaust fabricators such as CSK or Simpsons, I wouldn't be embarrassed to stick it next to a Zero, 'proper' PPE, or anything like that (from what I've seen on photos, anyway).
Next up... tidy up! What a bloody mess the workshop is now, tools and bits of grindings / filings everywhere :))
Adam, I really enjoy reading your updates and the pics, keep going!
That's a fantastic build well done. That's inspiration right there
Thanks guys! Hopefully it doesn't all fall apart on the first outing :))
In Mad Max news...
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Quite like the line made by the front bumper and the diagonals to the cage. Going to try and follow that theme on at the back...
I am no expert but I think the spare wheel location may hinder your vision.
(Still, an improvement on the 2 spare wheel set up...).
Like the way you have a mirror to check the front wheel is still there too.
Thanks for sharing. The interior rearview miror is a 8) detail...
Looks like you have the same seat I have!!
Quote from: Topdownman on November 2, 2020, 12:43I am no expert but I think the spare wheel location may hinder your vision.
(Still, an improvement on the 2 spare wheel set up...).
Like the way you have a mirror to check the front wheel is still there too.
This all made me laugh, a lot. Thanks :))
Got tyres fitted to mx-engineinwrongplace wheels today. They look black and round, happy days.
The car also ended up on its wheels momentarily as I was having a clear up.
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Then a rear caliper got pilfered to get The Bucket through an MOT, so it looks a bit sad at the moment.
However, pretty much everything that will be on the car is now on the car, so I'm tempted to chuck it on the scales...
Well. I didn't expect that. This is with about 10kg of fuel in too...
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Looks like I've got myself a budget Lotus. Just have to squint a bit :))
138bhp / 690kg = exactly 200bhp/ton 8)
Quote from: AdamR28 on November 3, 2020, 17:50Well. I didn't expect that. This is with about 10kg of fuel in too...
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Looks like I've got myself a budget Lotus. Just have to squint a bit :))
138bhp / 690kg = exactly 200bhp/ton 8)
Amazed but there isn't much left tbh.
Well done
Thanks - yeah not much left was the idea, haha.
Few more bits done this morning.
Shifter cage risers turned up, no point making them look all shiny.
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Shifter cut, bent, and rewelded to put it in a better position.
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Old vs new wheels / tyres. Ride height is still really high though! Will tackle this later.
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Quote from: AdamR28 on November 4, 2020, 09:37Thanks - yeah not much left was the idea, haha.
You are my heroe :-)
Lightness rules.
I had been calculating a bit and because of the roll cage arrives at a bit higher. The doors are probably heavier than expected.
The down side is that it does not remotely look like an MR2 anymore, but like a deadly jumping Spyder ;-)
Ha. Yes. I might make a 'Q&A' section and write it up on a panel somewhere.
First one will be 'What car is that?'...
Cant wait to see this out on track. I'm at Oulton 18th December with Circuit days, still places left too...
I've just booked the 5th... 18th will be near impossible for me with work sadly! That would have been ideal though. Next time...
Brakes sorted this morning. Bought some braided lines that appear to be the same as HEL, so they have a weird 'double flare' system which means they look wrong for the MR2!
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Basically the diameter of the highest point on the braided fitting is a little larger than a standard male flare, and smaller than a female, so it will cut its own seat into either as it goes in. Sounds like a bodge to me, but it works and means I don't have to change all the hard lines, so...
Well worth buying a decent tool for this job, makes it so easy and you get a good result every time.
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Front right hardline wouldn't free up from the flexi, so had to make a new one.
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Bled the brakes up, horribly mushy first time but it felt like air, so I let them gravity bleed a little, then bled again.
I use an old 2L drinks bottle, with a hole drilled in the lid, and a piece of clear PVC hose going into the bottle. The trick here is to block up the end of the hose (a bolt screwed in) and cut a 15mm ish long single slit lengthways in the hose, near the bolt. This opens up when pressure is applied, and closes on vacuum - et voila, just pump the pedal slowly and you have one person brake bleeding on the cheap.
Tested the brakes by jamming the pedal down with some blocks of wood, and turning the hub nut (rear) or a fully bottomed out wheel nut (front) and checking the torque at breakaway.
Rears were at 60Nm and 65Nm, fronts 70Nm and 75Nm, so that is about right - very close on balance left to right, and the fronts will definitely lock first. May revisit the brakes at some point though, as some sort of brake bias adjustment is always useful.
Pedal feel is currently... average. Feels a lot like the standard brake setup, or a kit car with a tandem master cylinder. Which figures, because all the piston sizes are virtually identical (tandem 0.7" master and just over 50mm front and just under 50mm rear piston diameters), as is the pedal leverage ratio. I may end up moving the master down and going back to the original clevis hole - but we'll see what it's like 'in the field'. Even though I am aware of it, the temptation is to prod the pedal much harder when just sat in the car stationary than when you would driving, which gives a false impression.
I think it will now drive and stop and stuff, so may wheel her outside later!
@AdamR28 re your diy one person brake bleeder-
I mentioned on here some time ago about having one of these in the 60's, I lost it over several house moves and it was unnecessary while having a company car. Since I have again started working on my own cars I found another, at £2.90. Not as low cost as diy if you already have the tube.
https://www.amazon.co.uk/Wot-Nots-Pearl-PWN189-Automatic-Brake/dp/B00ALTZEQ0/ref=sr_1_6?dchild=1&keywords=brake+bleed+tube&qid=1604583698&sr=8-6
Didn't think of using softer tube, that's a good idea for the next time I lose it / it breaks, thanks!
Squeezed the clocks in today, and the rear view 'mirror' - a cheapo reversing camera setup from ebay. Been wanting to try this for ages but previous similar projects were on strict self-set budgets. I'll take a mirror to the first track day just in case its shit!
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I figure I can see all the important stuff on the clocks, so that'll do!
So I've driven it less than a minute, and it needs:
- Brake adjustment, way too little pedal force despite the servo delete.
- Front brakes lock way before the rears, bias adjuster required.
- Front needs lowering 10mm or so.
- It understeers a lot. I do have the rear ARB disconnected but its going to need more intervention...
Positives:
- Driving position is brilliant.
- Its quick for an MR2!
- Chassis feels very taught.
- The Koni dampers are as good as I expected.
Ready for the next round of tweaks!
Also decided it is incredibly ugly :))
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@AdamR28 Good work, it starts, it steers, it stops, the rest is just adjustment.
PS. 10/10 for ugly, you've got that nailed no adjustment necessary!
Quote from: AdamR28 on November 7, 2020, 13:16- Front brakes lock way before the rears, bias adjuster required.
- It understeers a lot. I do have the rear ARB disconnected but its going to need more intervention...
Because the drive train is in the back, the bulk of the lightening has a strong froward bias. Your corner weighing is crystal clear.
The braking is indeed easily solved.
Apart from hooking up the rear ARB the understeer would need more testing at higher speed as you know way better than me.
As a matter of curiosity; I did read that you are on OEM springs but with thát much weight reduction, especially the front may be stiff? Cutting those down more will make them stiffer still.
How do you think this will fair at higher speeds given the extra drag of the open chassis?
Finally its finished. Cant believe how long it has taken you....
I cant be the only one thinking papier mache bodywork right?
Can of paint and she'll look lovely :))
It looks like a life size Lego Technic car :D
Quote from: Joesson on November 7, 2020, 13:41PS. 10/10 for ugly, you've got that nailed no adjustment necessary!
That made me laugh quite a lot. Ha. Thanks.
@Petrus , at the moment I have Tein lowering springs with 1 coil cut off the front and 3/4 of a coil cut off the rear. As standard they have the first one and a bit coils completely coilbound, so I figured this is a) safe and b) doesn't affect the spring rate much, if at all.
Ride height, to the lowest part of the pinch weld on the sill, has ended up 130 rear and just over 130 front - that's with the 25mm smaller than standard radius tyres, so working all that back it is about 5mm higher than standard despite the lowering springs!
As for handling balance, I can cope with understeer at low speeds as it allows you to trail brake more, but I really cannot deal with the front end not going where I tell it to at higher speeds or corners where you don't brake. So maybe if I can get the low speed balance close enough, I'll stick a big splitter or wing on the front for a laugh.
@JB21 I'm not expecting it to be able to get much over 100mph to be honest :)) Top of 4th gear looks to be just under 115mph so that matches 'ok'. I will add some sort of panelling to the front and sides though I think, mainly to keep driving water out and my arms in should there be any sort of bump.
Done a few more bits this morning and over the last few days, tidying up the rear end by making a new exhaust hanger / mount, enabling me to get rid of the weird 'cage' thing, and added a rear 'bumper'.
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Also chopped the ends off the standard rear ARB and added / cut and shut some (well, one side is, the other is fixed) adjustable drop links. This has in effect stiffened the rear ARB a touch which will help with the understeer, and gives me a bit of easy adjustment at the track if required.
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The ARB clamps are my own design and have an egg shaped / shallow V at the opposite end to the clamping bolt, so they clamp 1/2" through to 3/4" bars at 3 points (the sides of the V, and the bolt itself). The standard ARB is 15mm and I have some 5/8" (15.9mm) and 11/16" (17.5mm) bar knocking about, so can always increase rear ARB stiffness in future if required.
That said, I am not a fan of this on RWD cars. I spent a couple of years with a previous Westfield doing the maths, building and testing ARBs, changing spring rates, roll centres, etc - and ended up coming to the same conclusion as Caterham did when developing their R400 (I found the document after I'd finished, d'oh!): Soft springs and stiff bar up front, stiff springs and soft bar at the rear. It seems Toyota agree. And Lotus (no rear ARB on the S2 Elise, for example).
My feelings around this are:
- The ARB acts in torsion, so (depending on mountings etc) this effectively doubles roll stiffness for the same increase in single wheel bump stiffness. The front end of the car is what you feel first when turning, so it gives good driver feedback, and the softer single wheel bump is great for kerb-hopping.
- Uncoupling the rear as much as possible aids corner exit traction. If you have a really stiff rear ARB and are leaning on the outside rear tyre on corner exit, the ARB is then trying to lift the inside rear off the ground - not ideal.
- Mismatched wheel bump frequencies front to rear (front softer) means the car settles evenly after hitting a bump. The front hits it first, but oscillates slower, so by the time both ends have settled they are back in unison again.
- All in, my preference (and Caterham's) is to end up with the front ARB contributing around 40-50% to front roll stiffness, and the rear ARB 10-15%, then front wheel frequency around 10% lower than the rear.
I think Mr Poo is the same front and rear, or perhaps higher wheel frequency at the front, but I will test this at some point and lob all the numbers into my handling calculator.
Could you not bang a C60 box in this from the 2ZZ Celica? Mine tops out at 104mph in 4th. Should give you better acceleration?
Certainly interesting looking and pretty loud as well with no cat etc! :D
Aero wise i guess with speeds being achieved on a 1zz it should have not have too much impact on circuit but will be interesting to see difference with full body car running same power etc, funnily enough at weekend i was watching the wind tunnel test video Cletus did with Leroy his non-panel corvette compared to a full body car, results were staggering with something like 540hp needed to just push the air out the way at 170mph terminal speeds he does on drag strip with no panels, then only around 240hp for full body car to do the same!
Here is video link for some entertainment
Yeah, could change the gearbox but... cost and can't really be arsed. Fun to see what I can do with the standard stuff! I would definitely fit something with lower ratios if it died though.
Thanks for the link Ian, that is interesting and fun! In my head I had 0.7 for a Cd, so that's not far off then. I wrote a calculator when I built a previous car, so given that we're 'there' thought i might as well lob some numbers in it...
drag.jpg
So basically that gives a top speed of 109mph if I have 140bhp at the fly, 20% drivetrain loss, drag coefficient of 0.7 and the 'usual' coefficient for frontal area of width * height * 0.8.
Dropping Cd to 0.6 gives an additional 5mph. I don't think it will be worth the effort, haha.
Standard Cd for our cars is said to be 0.353 (roof up, windows closed), giving a CdA of 0.592 (metric units), which gives a theoretical top speed of 131mph with 138bhp, from my calculator. Published figure is 130mph so that's close!
I'll chuck Leroy's numbers through when I get chance, be interesting to see how the calcs match the wind tunnel - but my Westfield was really close. I'd estimated a top speed of 132mph and it does reach the limiter at 126mph ish fairly easily, with a bit more to go.
There's an online calculator here too, which broadly agrees with my findings: http://warped.org/vw/calc.html
20% drive train loss is pretty high don't you think?
Its effectively the same a fwd hatchback in that respect.
No prop shaft light weight gearbox only 4 cylinders.
Not that it really matters just my thoughts.
Yeah I would agree - just went for the same number throughout and what most dyno operators seem to use. Be interesting to get an 'at the hubs' figure.
Quote from: AdamR28 on November 10, 2020, 12:01Yeah I would agree - just went for the same number throughout and what most dyno operators seem to use. Be interesting to get an 'at the hubs' figure.
It would be interesting.
Most dynos quote 20 or even 25 percent for losses makes them look good cos you never get a before mods run.
I'll have a ring round some local dynos, see if any of them have had a standard MR2 on them - obviously the actual numbers may not be right, but to see a comparison would be good!
Just leaving this here as a reference for myself. Maybe I won't need that brake bias valve after all...
Screenshot_2020-11-11 Brake Bias Calculator Brake Cylinder Calculator Automotive Brake System Calculator BRAKE POWER.png
Quote from: AdamR28 on November 11, 2020, 06:12Maybe I won't need that brake bias valve after all...
The lager size at the rear might just do it.
I réally, RÉALLY enjoy this thread Adam. It is much too rare to see ome calculate to get into the ball park.
I love the formulae involved in the fysics as it adds to understanding and have my trusty ´91 TI-68 next to me on the sofa. Early seventies bought Irvings Tuning for Speed and got hooked on this from the gas/wave speed explantion/calculations in it.
As to aero, the lack of it will do away with the airfoil effect so yours will not have lift.
Adding some spoiler/wing at the rear would provide a breat/tear off ledge for the turbulent air´stream´ and reduce the drag. Because of the turbulence it will not result in much negative lift anywhichway so you can keep it flattish and it will not change your spring rate/suspension frequencey at speed.
Yes! 200bhp/ton!
I'm like, totally taking credit for that, thanks :)
So good to see proper engineering in a build thread. I'm thinking you must be in aerospace or automotive eng in some way? Leaning towards aerospace seeing the drag calcs... (Aero MSc here)
Also, I haven't checked in for a week or two, the accelerated timeline is amazing, how do you make such fast progress? I imagine it involves 100% less standing around scratching your head than my projects, and a better ratio than one hour completed work to ten hours researching online with 50 tabs open...
Love the little vid with you coming flying out the workshop at full chat haha
Quote from: iffyT on November 11, 2020, 18:07Love the little vid with you coming flying out the workshop at full chat haha
It was quite surprising yes :-)
As an aside, I certainly think the Cd is less than 0.7 if we compare to Leroy.
For one, the Munter doesn't have 2 massive turbos and a plenum chamber the size of a tool box sticking into the airflow, or a massive wing (or is this planned??). The Corvette also has a larger frontal area.
Have you thought about perhaps using some 3mm perspex like here: https://www.perspexsheet.uk/blue-750-perspex/ (I think you can find it cheaper), some rivnuts, and a heat gun and some old carpet and plywood as a former and go for a Ariel Atom type vibe?
Could help fill in some of those bits likely to cause turbulence, and maybe alleviate some of those horrified looks when you turn up at a track day (and beat their M3 by 2 seconds a lap) :)
Quote from: iffyT on November 11, 2020, 18:07Yes! 200bhp/ton!
I'm like, totally taking credit for that, thanks :)
Credit absolutely 100% yours, but sadly your dreams may have just been dashed... more on that in a bit.
I'm actually in the business of selling mountain bikes (weird looking ones with no seats for doing tricks on, specifically). ::) Though I kinda fell into that while at uni, starting up my business while 'studying' a very vague form of engineering - pretty much none of which I've used since.
However, I'm also a huge believer that if someone is interested in something then they'll put the time in to research and learn it themselves - cars and all things related holds my attention (perhaps too much of it sometimes!), hence the additional learning.
I go through phases of not sleeping very much, so getting up early and cracking on a for few hours before work is a good way to fill the time, and this time is wonderfully interjection-free. I love the solitude and peace of being up before 90% of the population (a virtual Covid-safe high 5 to all the other slightly autistic, borderline Aspergers or otherwise 'on the spectrum' sibling-free folks out there). With this project in particular, the lack of fucks given to neatness or cosmetics means I can just smash my way through stuff quickly!
Related to the above... I thought about posting this a few weeks ago, but having not been on the forum very long thought I'd leave it. But, I feel good today so why not. Cars help with my mental health. Tinkering and learning gives my mind something to do, a distraction, a focus, a challenge, a creative outlet, a release.
Mental health is something I've struggled with for more years than I haven't. Anxiety, low self-esteem, depression, an admittedly half-arsed suicide attempt in my late teens, then recently counselling, CBT, learning more about how the brain works, and support from those around me 'in the know' have started turning that around.
Now, this sounds a bit pie in the sky - and it can be difficult at times - but whatever traits you have which you may give yourself a hard time about can be positives under the right circumstances. A painstaking attention to detail, bordering on obsessive, and huge sensitivity to outside influences (interaction with mechanical things, noise, light) makes my brain ache at times and really takes the wind out of my sails, but on the plus side it has allowed me to build a successful business and do some truly unique things with cars, bikes and other mechanical objects. Everyone has a special talent of some sort - whether that is recognised by conventional education or not - and even though it can feel a burden, look for the positives!
Having opened up over the years about my mental health to various people - ranging from 'known them for 15 years' to 'randomers on a forum' - the responses have ranged from 'flip, I had no idea' to 'same here' to 'mate, that was brave, kudos'. I can't recall a single negative response. So if you're also struggling (seems common at the moment!) don't worry about speaking out, there's tons of support all over the place. Me for example - I'll never judge, so even if you just want to ramble a load of stuff to someone you'll never meet, and feel the weight of that burden drift away as you hit the 'send' button, you know what to do 8)
On other forums I have started a 'Mental Health Thread' for all to contribute to, and would be happy to do so again if deemed appropriate.
Anyway... back to Mr Poo. I'd previously had a read through some track day companies' T&Cs and thought the no bodywork thing was a bit borderline. I posted a few details on another forum which has a few TDOs on it and one point blank stated if I turned up, I wouldn't get on track, because the car 'looked poopoo'. No other reason. He couldn't argue with the safety aspect, and in fact agreed with me in some ways, but just it looked poopoo and that was that. Sadly, first impressions count, and being faced with an early bath from what should be a nice day out doesn't sound like my idea of fun.
So, the grinder was employed and a few kilos shed. Bonnet from 11 to 6kg, rear lid from 8 to 4kg, doors from 28 to 5kg (ish).
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And now he / she / it looks like this:
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Look how wonky the front end is from that shunt, haha.
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Decided the petrol cap mechanism was too heavy:
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And a shot of the standard side impact bars compared with what I've fitted:
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Doesn't look like I'll be able to stay under 700kg, but at least the car will be faster round a lap thanks to a much lower Cd!
Inspired by
@JB21 's thread, I decided to look at some aero improvements: https://www.mr2roc.org/forum/index.php?topic=70241.0
First up, reducing drag and lift at the front. 'Free' power and better handling for very little work, can't complain.
As standard, the size of the opening on the front grille is tiny once it's been mostly blocked by the numberplate. We also have those alloy pipes running down the full length of the car acting as big heatsinks. I've also seen a document where a 2.0L plane was successfully cooled with a 5x11" inlet, and have the nosecone on my 200bhp+ Westfield blocked off to a hole smaller than that, so figured we don't need such a big hole... less air being 'swallowed' by the frunk area means less drag and less lift.
Hole is 6 and a bit x 16 inches, so I may close this more if the car sits at normal coolant temp.
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Couple this with a way to get air out of the frunk area... and hopefully it is a decent gain (ducting not finished yet).
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The location, I'll admit, is a bit of a guess. Having looked at other similar cars (VX220 and Elise) I figure the low pressure area is a little further back than front engined cars which have a higher 'line' between bumper and bonnet, so the duct can go a bit further back.
The pressure plots below also helped with location identification. Blue is low or negative pressure, red is high pressure.
Even the badge creates a significant high pressure area and lift! The little lip in front of the duct seems to create negative pressure thereafter, which is good.
79c629e98086b77669adfe7f2b181495.jpg
This looks fairly close to the MR2, especially with the bulges at both sides.
CFD_Simulation_Car_Silvermine_Cp_Surface-1025x742.png
Notice how far forward the low pressure area is (dark blue strip) on this car with a quite high 'line' and sharp transition from bumper to bonnet.
MWR_Logo_stream2.jpg
This also looks pretty close to the '2, and has a fairly uniform pressure plot over most of the bonnet.
Streamlines2_iso_Creaform.jpg
So, with positive pressure going in (all the nose areas are bright red), and either negative pressure or neutral areas on the top of the bonnet, you can pretty much put the duct anywhere and air will flow out.
But why not help it on its way. The hole is pretty much the same size as the grille opening - I think, in theory, it should be a little larger as the warmer air on the way out has more volume, but I figure a bunch will escape down the sides of the rad and ducting (I can't be bothered making it really tight / neat).
thumbnail_20201113_084237.jpg
The little Gurney style flap helps to lift air up and over the hole, which generates negative pressure and 'sucks' air out. It is also a useful tool for breaking the airflow of the back of an object, reducing turbulence behind it and thus drag. I'll probably stick one on the very back of the car as well, for a laugh, and obviously on top of the 'windscreen' to help lift air and water over the occupants.
And some really scientific testing :))
Without flap... turbulent air immediately upon separation from the bonnet surface.
With flap... air is sent up and over - creating slight negative pressure where the hole is.
I think. I'm no aerodynamicist that's for sure, but it makes sense to my brain ;D
Mental health is like the last medical taboo.
Still people out there that don't believe in such a think.
I've been in therapy on and off for 18 months now and some days are hell and others are heaven.
Good luck on your journey.
I was getting excited for a minute there, I thought you had posted some ideas for painting the car....
Wind tunnels are so last year!
Quote from: iffyT on November 11, 2020, 18:07Yes! 200bhp/ton!
Over 250 is where the real fun is 😉
That's where mines at although I've added power not lost weight.
Quote from: 1979scotte on November 13, 2020, 16:03Mental health is like the last medical taboo.
Still people out there that don't believe in such a think.
I've been in therapy on and off for 18 months now and some days are hell and others are heaven.
Good luck on your journey.
It is only recently that I have made use of "Recent posts" and reading posts "backwards" is sometimes not the best way.
This post being a particular one of note, completely out of the blue we are into what can be a "taboo" area.
Having now read the thread in sequence I can see that we have, at least two, I shall call them brave members who tell other members of some of the troubles they experience.
Having met and regularly exchange banter with one and followed the interesting and positive thread of the other I was surprised. But that they feel that they can " speak openly" on this Forum , must show the generous and understanding nature of the Members.
Hopefully, the old saying that "a trouble shared is a trouble halved" will prove true and that sharing with however Members are active on here, will severely help reduce their troubles.
Thank you for sharing.
Much better with the bodywork back on mate. If you make a front splitter make me one too, lol.
Fair play with opening up on mental health too. I also suffer with it after losing a lot of loved ones far to early in horrible circumstances and i was also caught up in an industrial explosion/fire in work which resulted in fatalities and injuries to good friends. My boy also lives with ADHD so i understand what you're going through.
Having met up with you at three sisters you'd never know you struggle with mental health. My mate also struggles and he can be a bit awkward talking to strangers, you didn't come across like that at all.
Found this Adam if any good to you.
Quote from: AdamR28 on November 13, 2020, 15:17the responses have ranged from 'flip, I had no idea' to 'same here' to 'mate, that was brave, kudos'.
Put me down for 'same here'. Depression sucks balls but I do find it comforting that some of the most driven, capable and nice people I've ever met suffer similarly. My friends and family help me get through the rough patches, although unfortunately my project outlets sit gathering dust when times are hard. One thing I wish I could change.
All the best mate, and back at ya if you or any other of you mr2 peeps ever want to chat, PMs are open.
Car looking more svelte with the body panels on!
Quote from: iffyT on November 13, 2020, 23:42Car looking more svelte with the body panels on!
Recogniseable as an MR2 again.
The unwanted lift caused by the airfoil OEM shape is spoiled by the absence of the windscreen anyway.
Quote from: AdamR28 on November 13, 2020, 15:23So, with positive pressure going in (all the nose areas are bright red), and either negative pressure or neutral areas on the top of the bonnet, you can pretty much put the duct anywhere and air will flow out.
Hence I cut two vents where I best liked them aestetically.
Together they are still smaller than the entry but it is more than nothing.
Great insights, thank you for sharing
Quote from: AdamR28 on November 10, 2020, 09:38Quote from: Joesson on November 7, 2020, 13:41PS. 10/10 for ugly, you've got that nailed no adjustment necessary!
That made me laugh quite a lot. Ha. Thanks.
@Petrus , at the moment I have Tein lowering springs with 1 coil cut off the front and 3/4 of a coil cut off the rear. As standard they have the first one and a bit coils completely coilbound, so I figured this is a) safe and b) doesn't affect the spring rate much, if at all.
Ride height, to the lowest part of the pinch weld on the sill, has ended up 130 rear and just over 130 front - that's with the 25mm smaller than standard radius tyres, so working all that back it is about 5mm higher than standard despite the lowering springs!
As for handling balance, I can cope with understeer at low speeds as it allows you to trail brake more, but I really cannot deal with the front end not going where I tell it to at higher speeds or corners where you don't brake. So maybe if I can get the low speed balance close enough, I'll stick a big splitter or wing on the front for a laugh.
@JB21 I'm not expecting it to be able to get much over 100mph to be honest :)) Top of 4th gear looks to be just under 115mph so that matches 'ok'. I will add some sort of panelling to the front and sides though I think, mainly to keep driving water out and my arms in should there be any sort of bump.
Done a few more bits this morning and over the last few days, tidying up the rear end by making a new exhaust hanger / mount, enabling me to get rid of the weird 'cage' thing, and added a rear 'bumper'.
20201110_081209.jpg
Also chopped the ends off the standard rear ARB and added / cut and shut some (well, one side is, the other is fixed) adjustable drop links. This has in effect stiffened the rear ARB a touch which will help with the understeer, and gives me a bit of easy adjustment at the track if required.
20201110_081223.jpg
The ARB clamps are my own design and have an egg shaped / shallow V at the opposite end to the clamping bolt, so they clamp 1/2" through to 3/4" bars at 3 points (the sides of the V, and the bolt itself). The standard ARB is 15mm and I have some 5/8" (15.9mm) and 11/16" (17.5mm) bar knocking about, so can always increase rear ARB stiffness in future if required.
That said, I am not a fan of this on RWD cars. I spent a couple of years with a previous Westfield doing the maths, building and testing ARBs, changing spring rates, roll centres, etc - and ended up coming to the same conclusion as Caterham did when developing their R400 (I found the document after I'd finished, d'oh!): Soft springs and stiff bar up front, stiff springs and soft bar at the rear. It seems Toyota agree. And Lotus (no rear ARB on the S2 Elise, for example).
My feelings around this are:
- The ARB acts in torsion, so (depending on mountings etc) this effectively doubles roll stiffness for the same increase in single wheel bump stiffness. The front end of the car is what you feel first when turning, so it gives good driver feedback, and the softer single wheel bump is great for kerb-hopping.
- Uncoupling the rear as much as possible aids corner exit traction. If you have a really stiff rear ARB and are leaning on the outside rear tyre on corner exit, the ARB is then trying to lift the inside rear off the ground - not ideal.
- Mismatched wheel bump frequencies front to rear (front softer) means the car settles evenly after hitting a bump. The front hits it first, but oscillates slower, so by the time both ends have settled they are back in unison again.
- All in, my preference (and Caterham's) is to end up with the front ARB contributing around 40-50% to front roll stiffness, and the rear ARB 10-15%, then front wheel frequency around 10% lower than the rear.
I think Mr Poo is the same front and rear, or perhaps higher wheel frequency at the front, but I will test this at some point and lob all the numbers into my handling calculator.
Quote from: FredyCro on November 14, 2020, 11:19Great insights, thank you for sharing
Quote from: AdamR28 on November 10, 2020, 09:38That said, I am not a fan of this on RWD cars. I spent a couple of years with a previous Westfield doing the maths, building and testing ARBs, changing spring rates, roll centres, etc - and ended up coming to the same conclusion as Caterham did when developing their R400 (I found the document after I'd finished, d'oh!): Soft springs and stiff bar up front, stiff springs and soft bar at the rear. It seems Toyota agree. And Lotus (no rear ARB on the S2 Elise, for example).
Toyota by way of TRD goes to relatively stiffer still rear springs and maintains the same softer rear ARB ration.
Well, thanks for the support guys and I also hope those who struggle / are struggling with your brains at the moment have an outlet. Always here if you need!
@JB21 thanks for the YouTube link Phil, that is interesting. I ended up in a bit of a YouTube Black Hole™ for a few days after that, doing loads of CFD and aero research. After that I exchanged a few messages with a mate who runs the wind tunnel at Southampton Uni - he's done some work with the M-Sport WRC team and he confirmed I was along the right lines, plus added a few tips.
The plan is to reduce drag as much as possible (while still applying the 80:20 rule - 80% of the function for 20% of the effort!), and have a small nod to downforce while I'm at it. The balance of the car will be significantly upset from standard, so it'll need a bit of iteration to get it set up now - figure I can add downforce where necessary as I go.
Haven't done much actual work on the car recently, more been thinking about aero, but have done a little tidying up of wiring, fitted an FIA cut-off into the rear firewall, added a few switches for lights and a cheapo reversing camera / screen as a rear view mirror (lighter and less drag! ;D ), plus rigged up a Koni damper adjuster as the 'key' to start her up. Because why not? I always lose these things and I figure I'll either have the engine running OR be adjusting the dampers, not both...
20201119_123059.jpg
Hoping to get a few more hours fettling today - though I have other cars to fix. The Bucket has a leaky rear caliper and my partner's Fabia has lost power steering. It doesn't rain...
Looking forward to (copying) your aero creations.
If you want a head start... :D (Bear in mind I'm mainly going for low drag, rather than downforce)
- Block up around half of the nose cone air intake, and duct this to the radiator.
- Block up the faux brake ducts on the bumper.
- Cut a big hole in the bonnet and duct radiator air out of there.
- Gurney flap at the rear to move the region of lift / negative pressure further back from the car.
- Add aerofoil shape to the roll cage. This is banned under MSA rules which indicates it probably does something! My basic calculations show I can drop the overall drag of the car by nearly 10% from doing this!
- Cut slots / fits louvres to the tops of the wheel arches front and rear.
- Fit wheel deflectors front and rear, extending right up and making some vertical air 'dams' to prevent air entering the wheel arches (see Page 10: http://publications.lib.chalmers.se/records/fulltext/250512/250512.pdf - and pages 18-19 and 23-24 for the amazing results!)
- Maybe even enclose the rear wheels like the original Honda Insight (see Page 11 of the document above) - but have concerns about brake cooling if I do this...
- Add a flat floor.
Then drive it, maybe add a rear wing, or a wing mounted to the roll bar, depending on what aero handling balance is like.
Some little snippets of info I've hoarded, uploading here for safe keeping / general interest...
Screenshot_2020-11-17 Drag coefficient of shapes Shape factor explained - F1.png
wheel-enclosure.pdf
More bits of progress today...
Made a little tool to allow me to louvre the engine cover - just a bit of steel with a slot ground in it. Worked a treat!
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Tested with the heat gun - the standard side didn't lift a strip of paper when air was blown across the panel, the louvred side did. That should help suck hot air out of the engine bay, and depressurise it should any air get in there somehow (drag and lift reduction).
Had a quick look at The Bucket - it has little deflectors in front of the front wheels, screwed onto what looks like some sort of diffuser sending air towards the front brakes. Clever. Mr Poo's had obviously disappeared in the prang!
IMG-20201119-WA0017.jpeg
I have a feeling that the position of the 'dam' is more to keep air out of the wheel arch than away from the tyre - I think I'll go much longer in an attempt to block both, then add brake ducting if required.
Bought a nibbler off eBay: https://www.ebay.co.uk/itm/5pc-Double-Head-Cutter-Sheet-Metal-Nibbler-Cutter-Power-Drill-Attachment-/333753702487?_trksid=p2349624.m46890.l49292
Wasn't expecting much for the money, but it made mince meat of the bonnet! Highly recommended, very handy tool to have.
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Quick tidy up with the file, aerocatches in, and the bonnet / front end is finished (apart from some extra ducting to the radiator).
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Yep, looks crap. Function over form for this one as you may have guessed by now ;D
Function over form every time.
Unless Rachel Riley comes calling 😳
Quote from: 1979scotte on November 20, 2020, 22:29Unless Rachel Riley comes calling 😳
...and make form functional.
@AdamR28 Iirc I have read on here that the "little deflectors / the dam" is to aid front end stability.
Yep that makes sense looking at the pressure plots in the last PDF I linked to. They will also reduce drag / improve fuel economy.
PS: I also have a lot of time for Rachel Riley!
Quote from: AdamR28 on November 21, 2020, 08:45PS: I also have a lot of time for Rachel Riley!
Fun and smart ticks both boxes 😉
Just what I was thinking / meaning! ;D
Made some progress with B&Qs finest today.
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Making a rather huge flat floor!
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I think I may have overcooked this a bit, but we'll see in the real world I guess...
But for now, some maths:
Air at 100mph hitting a flat wall head on creates pressure of approximately 0.18psi. That's pounds per square inch.
This chap has a really interesting channel with some good real world data:
Which agrees with CFD info I've found:
(https://robrobinette.com/images/S2000/Aerodynamics/CFD_Airdam_Splitter_Pressure.jpg)
(https://i.imgur.com/wnW3Hc4.png)
Basically, even without a front splitter, a flat floor can create a heck of a lot of downforce!
This is rough numbers and I am cutting a few corners, and making assumptions, but bear with me...
The front of the flat floor on my car is around 70" wide for perhaps 18", tapers in to about 36", then behind the wheels is 48" wide all the way back.
Using 0.18psi at 100mph, and the data from Julian's video, you will get approx 0.125psi at the front of the floor, 0.04psi in the middle, and (with a reasonable diffuser) 0,085psi at the back. I probably won't fit a diffuser, so I'm going to halve this number.
I will also reduce the total downforce by 20% as Julian's numbers will be at the centreline of the car, and air 'bleeds' away around the sides of the floor (unless I fit some side skirts!).
So lets split the floor down:
Front = 18" x 70" = 1260 square inches.
Middle = 40" (average) x 64" = 2560 sq inch.
Rear = 48" x 64" = 3072 sq inch.
Front: 1260 sq in x 0.125 psi = 158 lbs.
Middle: 2560 sq in x 0.04 psi = 102 lbs.
Rear: 3072 sq in x 0.04 psi = 123 lbs.
Reduction of 20%
Total: 306lbs / 140kg of downforce! That would be enough to lower the car about 15mm at speed, which would be, er, interesting.
For comparison, I did the same maths based around the same assumptions for a 6" front splitter and front tray the same size as mine, with no full flat floor. Total downforce just over 100kg, but obviously all of it ahead of the front axle (not as good aero balance), and much more total drag.
(https://www.verus-engineering.com/web/image/10472/data-wm.jpg?access_token=0b72438b-bd0b-416c-bd09-ad135e81f71b)
Of couse the other possibility is that I've made a huge mess of it and the car will take off!
Anyway, enough theoretical stuff - more pics from today.
Made a bracket up to hang the front of the floor from the chassis. Makes it easier to get on and off, and makes sure it bolts to something solid.
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Also gives some grab handles for a very awkward piece of wood!
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The eagle-eyes will spot a plate bolted to the rear edge of the front undertray - this allows it to be hooked up on top of the rear part, so fitting and removal is still a one man task and means you don't have to balance it on your head :))
More shaping. I once made the mistake of cutting both sides 'freely' rather than cutting one half then using the offcut as a template. Looked rather wonky, as you can imagine! This one still looks a bit bog eyed but I think it's just the whole front end of the car being bent.
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Chopping clearance for front wheels on full lock both ways...
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Checking exhaust and sump clearance. I'll add a NACA duct just in front of the sump to give both of these areas some airflow / cooling.
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And here's where I finished today, about 4 hours work to this point.
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Looks like a massive splitter but once the air dam is in there there won't much much sticking out at all. I want to keep it this way to make the car look a bit less 'developed'.
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Also going to add some deflectors underneath as discussed above, and some more at the very rear sides of the splitter / undertray to fire air around the sides of the wheels.
Obviously needs some paint to seal it, but total weight about 25kg. Heavier than I wanted but hopefully the trade-off will be worth it...
Awoken at 3:30am again this morning by a knee to the hip and an elbow in the shoulder (thanks Jane! :)) ) so decided to do some more fettling before work.
Boot lid is fitted. I cut some slots at the front edge and put stood-off countersunk bolts into the hardtop mounting bracket holes, then two push-button type catches at the back. The bonnet is fitted by clipping in at the front, pushing forward to locate the bolt heads over the slots, and pushing down at the rear to secure the on the catches. Simple, light, quick to remove (main concern given how much oil this thing burns!).
Fitted the driver's side door skin. I'll gaffer tape up the shut lines too.
Made some spreader plates / nuts for the tunnel-facing harness eye bolts. Was prepared to buy some but couldn't find M10 x 1.25 anywhere! 7/16" UNF the other side, weirdly, so the eyes I had screwed straight in.
Fitted the scuttle and made a 'windscreen'. It's really surprising how little height you need to direct air over your head effectively, when you're sat low in the car. Still need to make the passenger side, this will probably be just a plain lip of about 25-30mm, also out of lexan.
Added a bit more to the ducting out of the bonnet, that's almost completely sealed now.
It's actually starting to look half decent ??? I really, really hope the trackday at Oulton on 5th December goes ahead with whatever new rules the mongs in charge come up with next.
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Good progress as always.
That looks like thick plywood and 25kgs is a lot of weight in the scheme of things. Will you look at lighter options if it works?
If you are buying paint, would be rude not to do the whole car, it would probably help getting onto trackdays too!
You can use rustoleum on wood as well as metal.
https://tools-paint.com/rustoleum-combicolor-7300-gloss-metal-paint-standard-colours-25l-16925-p.asp
Ah, Rachel, Sean Locks finest moment....
https://www.youtube.com/watch?v=Nrty2XITqTE&ab_channel=SubOnPoonGoonOrEatShit
Decided to use SBR primer on the floor instead, have a few litres leftover from a roofing job which will go to waste otherwise. It'll be fine without paint, too much weight added and time wasted making it look pretty :D
The ply I used is 9mm. Most people use 12. I looked for lighter options but really struggled to find anything for similar cost (or even 2, 3, 4 times the cost) that was lighter for the same stiffness, or stiffer for the same weight. Perhaps I have missed something though!
Haven't seen that clip before, hilarious!!
Quote from: Topdownman on November 23, 2020, 09:59That looks like thick plywood and 25kgs is a lot of weight in the scheme of things.
For the floor thinner would be ok as long as there are enough mounting points to spread the load; see the OEM plastic underthingies.
The splitter however needs to be sturdy. The usual twin tie-rods between front edge of the splitter and the chassis are a popular way to minimalise the strength of the plate needed.
Quote from: Petrus on November 23, 2020, 11:22For the floor thinner would be ok as long as there are enough mounting points to spread the load; see the OEM plastic underthingies.
The splitter however needs to be sturdy. The usual twin tie-rods between front edge of the splitter and the chassis are a popular way to minimalise the strength of the plate needed.
Given the sorts of loads a flat floor can develop, and the locations of said loads, I went thicker to be on the safe side. As the images above show, you can actually end up with higher peak downforce over a larger area somewhere around the front axle, than at the splitter...
Why 9mm mate?
Is it rigid enough?
I suppose with enough fixing points it would work.
Yeah, I think it will be enough, based on feel, the maths above, having made similar out of 12mm before (https://www.mr2roc.org/forum/index.php?topic=70241.msg838365#msg838365), and not having overhang at the front.
There's 5 fixing points along the front at the area of most load, 2 more at the back of the front piece, then the front and rear pieces interlock, and the rear has 3 fixings along the front edge and will have a further 6 spaced pretty equally around the rest of it. With a 'tug test' the whole lift flexes and wobbles a fair amount.
I figure most of the loads will be evenly distributed, so if I can stick a couple of 10kg weight plates in any single location, it ain't coming off. Hopefully. Fingers crossed!
Quote from: AdamR28 on November 23, 2020, 11:50Given the sorts of loads a flat floor can develop, and the locations of said loads, I went thicker to be on the safe side. As the images above show, you can actually end up with higher peak downforce over a larger area somewhere around the front axle, than at the splitter...
It is either thinner with loads of fixtures to distribute the load or thicker material to do that over less.
It´s a choice you made.
The issue with the splitter is the possible tórque on the rear mountings. Hence the popular tie rods.
Again there are more roads to Rome.
You btw highlight a very interesting and little understood/known fact; that súction is a lót more significant in downforce than forces pushing down.
On a rear ailleron per exampe the angle of attack is not to maximise the direct force against it but to maximise the speed of the flow underneath it. This illustrates the function of a small deck lip under it.
Anyway, bottom line is that I lóve your aero efforts. It is véry effective at surprisingly low speeds and the lighter the car how bigger the effect.
This is the core of the myth that is doe not make much sense on road cars ´because they do not go fast enough.´ Well not exactly. Not fast enough for the forces to be large enough to have much effect on the weight of the car.
On your car the forces have almost three times the effect it would have on an SUV.
As the standard Spyder/roadtser in only 1000-1100 the argument applies too; anything aero has two times the effect it would have on a 2 tonne SUV.
Top work on the flat floor, pretty much the same that I've marked out and up using foam backed board for a template.
Still undecided on final material though, but may give 9mm ply a shot.
We work with a lot of flat galvanised steel at Work and have loads of presses and folding machines. Just need to check the weight of 1.5mm galv sheet vs ply.
Quote from: Gaz2405 on November 23, 2020, 19:49Just need to check the weight of 1.5mm galv sheet vs ply.
Steel density is about 8 and ply 0.8, less than the 1.0 of water ;-)
So about 10 to 1.
So 1.5 mm steel is roughly 15 mm ply.
There is a véry sturdy variant of foam board with pvc outer layers. I have the 6 mm. one as side plates for the rear ailleron but is is avialeble in different thickness too.
The most dense variety is 0.4 and you could probably use thinner than 9 mm.
It is véry easy to work with and none too costly.
The stuff is widely used for shop sign boards p.e.
Imo great for this application.
Quote from: Gaz2405 on November 23, 2020, 19:49Top work on the flat floor, pretty much the same that I've marked out and up using foam backed board for a template.
Still undecided on final material though, but may give 9mm ply a shot.
We work with a lot of flat galvanised steel at Work and have loads of presses and folding machines. Just need to check the weight of 1.5mm galv sheet vs ply.
Have a look at ABS plastic sheeting. Not to expensive and is very strong and lightweight, this is what i'm looking to use for a front splitter.
Quote from: Gaz2405 on November 23, 2020, 19:49Top work on the flat floor, pretty much the same that I've marked out and up using foam backed board for a template.
Just need to check the weight of 1.5mm galv sheet
Cheers Gaz, good to know our ideas align.
Same size floor as mine in the stuff Petrus mentioned (0.4 density at 6mm thick) would be 22kg, 4mm ABS would be 39kg, and in 1.5mm steel would be 105kg!
I think there's a good reason many people use ply - as well as the weight not being bad, it is cheap (under £50 for two 8x4ft sheets), easy to get hold of (Wickes, B&Q), easy to work with, and pretty resilient to knocks.
Phil, just realised I have a slightly damaged (easily repairable with some wood glue) splitter that came off the front of Matts S2k MX5, you're welcome to it if you want, the shape is pretty good for the MR2. Can grab a pic and dimensions if you want.
Quote from: AdamR28 on November 24, 2020, 08:25Quote from: Gaz2405 on November 23, 2020, 19:49Top work on the flat floor, pretty much the same that I've marked out and up using foam backed board for a template.
Just need to check the weight of 1.5mm galv sheet
Cheers Gaz, good to know our ideas align.
Same size floor as mine in the stuff Petrus mentioned (0.4 density at 6mm thick) would be 22kg, 4mm ABS would be 39kg, and in 1.5mm steel would be 105kg!
I think there's a good reason many people use ply - as well as the weight not being bad, it is cheap (under £50 for two 8x4ft sheets), easy to get hold of (Wickes, B&Q), easy to work with, and pretty resilient to knocks.
Phil, just realised I have a slightly damaged (easily repairable with some wood glue) splitter that came off the front of Matts S2k mx-engineinwrongplace , you're welcome to it if you want, the shape is pretty good for the MR2. Can grab a pic and dimensions if you want.
That would be great Adam, thank you.
158cm wide, 69cm deep, 12mm ply. Should fit in a normal car for transportation. I may be down Skem / Ormskirk way this weekend if the weather is decent and can bring it if that helps!
Quote from: AdamR28 on November 24, 2020, 09:05158cm wide, 69cm deep, 12mm ply. Should fit in a normal car for transportation. I may be down Skem / Ormskirk way this weekend if the weather is decent and can bring it if that helps!
That would be great mate. I'll PM you my number 👍
Quote from: AdamR28 on November 24, 2020, 08:25I think there's a good reason many people use ply - as well as the weight not being bad, it is cheap (under £50 for two 8x4ft sheets), easy to get hold of (Wickes, B&Q), easy to work with, and pretty resilient to knocks.
Wood is basically a supermaterial.
It is still used in airobatic competition planes even.
Not bad at all.
Ply has the additional pre that the fibers run multidirectional so the sheet is highly resistant to tears if it would be damaged.
Made a start on the air dam this morning.
The aim behind this is to reduce drag more than create downforce, so I haven't left a massive front lip / splitter. The idea was to leave just enough to hold a region of stagnant air / boundary layer, and feed it down the sides of the car.
The dam is made from 1mm HDPE. I love this stuff - cuts with decent scissors, can be shaped by hand with the aid of a heat gun, light, tough, cheap. Add some curves and it's surprisingly stiff, too. I had to make it in two halves and join due to 'physical restraints' (my sheet metal folder isn't wide enough, nor was what I had left from this sheet of HDPE!), but with hindsight that is fairly handy in case it gets battered.
thumbnail_20201125_085915.jpg
Also made the tabs / deflectors around the wheel arch. The effect of these are shown in the PDFs a few posts back - but in short they create low pressure immediately after the lip and fire the air downwards. This reduces lift and drag by lowering the air pressure within the wheel arch, and reducing the amount of underbody air that gets caught up in the 'squirt' generated by the front tyres.
I'm also hoping these will pull hot air out of the arch and help with brake temps too. I will probably cut / slot / louvre the tops of the front arches as well for belt and braces. I have space and option to add ducting from the front air dam, but would like to avoid this if I can for drag reasons.
thumbnail_20201125_090013.jpg
The front of the car will drop around 100mm from where it is now, so that leaves approx 80mm from splitter to floor and 55mm to the bottom of the deflectors, which should be enough. However, another benefit of the HDPE is that it will grind away to a 'natural' height with use!
thumbnail_20201125_085952.jpg
I still need to 'fill in' the gap above the air dam end deflector and the front wing to keep air away from the tyres as much as possible, but still pondering about how to attach these. I would like to keep them 100% attached to either the wing or the splitter if possible, to make removal of either part easier. I think I may have to give in and use a screw or two in both parts though!
Here's one of my stupid little videos to finish. Not hugely indicative as there is no air flowing to the side of the deflector, but hopefully shows how this small feature should really help to reduce the amount of air going to the spokes of the wheel - and thus turbulence, and drag.
Was wondering what that air dam material was on Matt's MX5.
Quote from: JB21 on November 25, 2020, 14:29Was wondering what that air dam material was on Matt's mx-engineinwrongplace .
It is extremely versatile. Must have well over km. of tubing on the farm p.e.
One quality is that it although it gets harder with lower temps, even at -10 it does not get nearly as brittle as most other plastics.
This summer we put in a connection to the sewage system; over 100 meters of it with nylon inner tube.
Whether using sheet or tube I prefer cutting with a Stanley knife over scissors; it leaves a neater straight angled edge.
It is not particularly lightweight though.
Quote from: JB21 on November 25, 2020, 14:29Was wondering what that air dam material was on Matt's mx-engineinwrongplace .
Haha. Nah, Matt's was one from BYC Designs, albeit an early 1-piece version without the 'tabs', which made it a pain to fit! https://bycdesigns.co.uk/your-track-car/universal-fitment?product_id=167
It is raining quite hard now and that reminded me; have flood ´board´ for some doors. Those panels are foamboard with aluminium on either side. This too is availeble in a wide range of thickness and with a strength belied by the weight.
DiBond. About 4 times the cost, and around the same weight in 3mm thickness (6kg per square metre) as 9mm ply.
Quote from: AdamR28 on November 26, 2020, 10:31DiBond. About 4 times the cost, and around the same weight in 3mm thickness (6kg per square metre) as 9mm ply.
Wood ís a supermaterial.
Until it gets wet ;D Which is why the floor is currently bathing in SBR.
Done a few small bits and bobs these last couple of days, but as usual towards the end of a project, progress is now slow and barely visible.
Front wheel deflectors extended.
20201126_144532.jpg
Radiator fully ducted in, and mesh added in front of the radiator. I've seen engines lost to a pinhole in a rad before so not taking any chances! Having the mesh as close as possible to the core gives better airflow.
20201126_144758.jpg
Also fitted the spreader plates / harness eye bolts, made some more mounts for the floor, and started gaffer taping up the panel gaps.
It looks like MSV are running their December track days so I get to play out next weekend ;D
In longer-term news, I'm expecting this engine to spectacularly shit the bed sometime, so have ordered a new sump and some baffle flaps to make a proper one ready for the replacement engine.
Quote from: AdamR28 on November 27, 2020, 09:58Until it gets wet ;D Which is why the floor is currently bathing in SBR.
Remember the ´Spruce Goose´?
The Hughes H-4 Hercules was a sea plane. Made of wood ;-)
Way too young to remember that ;D
Quote from: Petrus on November 28, 2020, 11:35Quote from: AdamR28 on November 27, 2020, 09:58Until it gets wet ;D Which is why the floor is currently bathing in SBR.
Remember the ´Spruce Goose´?
The Hughes H-4 Hercules was a sea plane. Made of wood ;-)
DH.98 Mosquito "The Wooden Wonder"
Quote from: AdamR28 on November 28, 2020, 12:03Way too young to remember that ;D
The Morgan chassis will do then ;-)
That is btw also a very good example of the chassis being part of the suspension system.
Technically the Morgan uses a steel chassis, and always has - apparently.
Quote from: AdamR28 on November 28, 2020, 16:22Technically the Morgan uses a steel chassis, and always has - apparently.
Correct the wood is ash and is there to support the body.
Found that out after watching a documentary until then I thought the same.
Quote from: AdamR28 on November 28, 2020, 16:22Technically the Morgan uses a steel chassis, and always has - apparently.
It´s aluminium nowadays I think but that is irrelevant as indeed it is the framework which is wood and which I took to be part of the chassis. I thought it played a part in the suspension mounting.
Proves the point though that wood is a surprising and neglected material. Good for you to make use of it!
For a particular birthday in 2015 I went to the British F1 Grand Prix, Le Mans 24 Hour and the Morgan Motor factory tour, complete with cream tea.
Mrs J accompanied me to the Grand Prix and the Morgan factory, the latter with some reservation, but she found it to be really interesting.
Little has changed over the years of manufacture and I particularly liked the efficient use of the sloping site. The car build starts at the top of the slope and as the chassis is built up it is pushed downhill from workshop to workshop.
Until very recently the chassis were steel that was available with a galvanised finish, superseded by modern paint finishes and now bonded aluminium has replaced the steel. The ash frame is laminated and formed with really old instruments of torture, well that's what they look like.
Having visited more modern car manufacturing sites up to the mid 80's the workers at Morgan did seem more enthusiastic and engaged with what they were building than
BMC and Ford workers were in the past.
Morgan's are sold at a premium price but do hold their value well.
The cream tea was very home made in style, served in the works canteen, but all very enjoyable.
Quote from: Joesson on November 28, 2020, 20:31Morgan's are sold at a premium price but do hold their value well.
Which is why per March 2019 they are fully owned by the Italian investment group InvestIndustrial.
Some more bad photos of an ugly car :))
NACA duct fitted to the floor, sucking air in to cool the sump and exhaust.
20201129_145851.jpg
20201129_145905.jpg
Popped it back on the floor. The only thing left to go on a left hand door skin, at 5kg.
20201129_161412.jpg
So obviously not as light as body-less, but sure as hell will be faster round a lap without terrible aero!
The floor and splitter ended up at 23kg, and there's currently no passenger seat and harnesses, meaning the bodywork is about 50kg total even with the doors and both lids skinned (assuming 5kg taken off when I removed the 'bumpers').
20201129_164605.jpg
Got a few odds and ends to sort out before the weekend, but feels like I'm almost ready to shove it on the trailer!
Looks quite cool actually and 750 is still 150 kg lighter than mine which is about the same lighter than OEM but a bigger % so stíll :o
Very excited to see this go around Oulton. Power to weight is very similar to my 2zz now but with yours being lighter, better aero, better driver and you don't have to worry about driving it home, I'm guessing a couple of seconds quicker than mine if it stays dry. I managed a 2:04 last time out in June on AR1's in 30 degree heat.
Two different ways of skinning the same cat, eh :D Always an interesting comparison.
The previous Munter (115bhp, 800kg) did 2:04s at Oulton so even with the wank tyres I'm hoping M2 will be similar. The chance of getting a clear lap on a dry track on a sold out day at Oulton in winter? Minimal, but we'll give it a go. Hope my cheapo FauxPro camera lasts the day.
Quote from: AdamR28 on November 30, 2020, 10:25Two different ways of skinning the same cat, eh :D Always an interesting comparison.
The previous Munter (115bhp, 800kg) did 2:04s at Oulton so even with the wank tyres I'm hoping M2 will be similar. The chance of getting a clear lap on a dry track on a sold out day at Oulton in winter? Minimal, but we'll give it a go. Hope my cheapo FauxPro camera lasts the day.
Oh dear Adam - don't talk about cats in that way - I've just lost mine.
I honestly think it looks decent! Proper purposeful and non-tryhard track car. Really love the taped up doors and mirror mount holes! ;D
@Chilli Girl - really sorry to hear about your cat. Feel better soon!
Really sorry to hear about your cat, Jane. Our little furry friends really do become part of the family, don't they? As Lee says, I hope you feel better soon.
Haha. Yeah I went to town with the gaffer tape. Was cruising down the M6 yesterday and got overtaken by a white rep-mobile that clearly does lots of motorway miles between washes. The amount of turbulence displayed around the door handles and shut lines - especially at the rear where the flow is already interrupted - was impressive. Something along the lines of this...
(https://image.shutterstock.com/z/stock-photo-extremely-dirty-white-suv-car-parked-near-the-bush-after-the-adventure-in-the-outback-of-western-1311039002.jpg)
The dirt in front of the shut line indicates the airflow has been sufficiently disturbed by the gap to reverse in direction - pulling dirt with it, but also adding drag to the car.
I have recently started to take notice of these aero nuances, including the front (and rear) wheel deflectors, and flow separators around the area of the rear lights. Saw a great example today on some sort of SUV but can't for the life of me remember what it was!
Anyway, the idea of these is to try and 'break off' the air that would otherwise normally flow around the lights / side of the rear quarter, then separate and cause a low pressure region, generating drag. Using a sharp corner, or in the case I saw this morning a small 'ridge', helps prevent the air from 'sticking' to the car as it swaps around. This means the low pressure region is further away from the rear of the car, thus reducing how much 'pull' it can exert backwards (it's only pulling on air, not the rear panels of the car). Just found a photo of the latest Civic which is a good example - the shape of the lights, the detail in the lights, and the little deflector:
(https://www.autocar.co.uk/sites/autocar.co.uk/files/honda-civic-rear.jpg)
So I plan to add some of these to Mr Poo. Marginal gains, but it's a good talking point!
Quote from: AdamR28 on November 30, 2020, 10:25Two different ways of skinning the same cat, eh :D Always an interesting comparison.
The previous Munter (115bhp, 800kg) did 2:04s at Oulton so even with the wank tyres I'm hoping M2 will be similar. The chance of getting a clear lap on a dry track on a sold out day at Oulton in winter? Minimal, but we'll give it a go. Hope my cheapo FauxPro camera lasts the day.
2:04 with PTW of 7kg/hp....NICE!!! Well i'm now expecting a sub 2 minute lap Adam with the M2 at 5.4kg/hp, no pressure :-)
Quote from: AdamR28 on November 30, 2020, 11:33So I plan to add some of these to Mr Poo. Marginal gains, but it's a good talking point!
The more marginal deflectors do very little but they nevertheless help add up to notably more stability, not necessarily more speed. The added stability though leads to more feel thus more confidence thus indirectly more speed.
I was expecting an effect of the rear deck lip ofcourse, otherwise I would not have bothered but the perception of stability was greater than expected. It was the motivator for going down the hole of aero info on the web and fitting the SillyBigWing. This time it, incombo with the lip, does exactly what expected.
Good to know Petrus, thanks!
I plan to add a rear lip at some point too, but not sure how it will work on a car without a roof (or windscreen!)...
From what I can tell, there is separation on a standard car as air flows over the roof (image below). Notice how the rear window doesn't clear of water droplets when driving along first thing in the morning? There's no / very little moving air there to blow it off!
The air basically gets punched up by the front of the screen, skims the roof a bit, then off into the ether.
airspeed.jpg
So, two things, when you have a roof:
1) Any rear wing needs to be up pretty high to be within any significant area of flow, for it to be effective.
2) However (can't find the documentation / reference now), adding a little lip to the boot lit can improve the effectiveness of the rear wing. My sketchy memory of this is that air builds up against the lip, leaving a stagnant region which increases the thickness of the boundary layer all the way along the boot lid to the base of the rear window. This has effectively 'filled in' that region, so the air can stay 'stuck' to the rear window better - making that blue region in the image above thinner, and the yellow area closer to the boot lid, so a wing doesn't have to be as tall to work effectively.
However, the study was on some sort of front engined car, so this may not work at all once you start adding vents. In the MR2's case, using a small lip to attempt to build a thicker boundary layer on the rear lid may end up reducing cooling and have air 'spilling' down into the vents. Either way, this document gave me a clue as to how counter-intuitive aerodynamics can be, and how little I know about it!
Leaving the screen on and removing the roof puts all this to pot again, with the wing having to be REALLY high to get into any sort of useful airflow. Obviously the image below isn't an MR2, but it also handily illustrates just how changing the angle of the roof / rear window can maintain flow separation over it - meaning you don't need a huge wing. Wonder if this is where the term 'fastback' came from?
(https://media.springernature.com/original/springer-static/image/chp%3A10.1007%2F978-981-287-978-3_40/MediaObjects/371438_1_En_40_Fig7_HTML.gif)
I've seen data that suggests removing the roof can add up to 25% drag in some cases!
Removing the screen and roof completely? I don't really know what that will do. My initial guess was that removing the windscreen probably turns the whole passenger compartment into a large low pressure region, increasing both drag and lift. However, I then saw this... which is basically an extreme version of what I currently have. It appears a bigger 'lip' - probably in front of, but maybe also behind the cooling duct according to an article I just read - may even be enough to shoot air completely over the cockpit!
Very interesting
@AdamR28 and food for thought.
However, I can't help feeling that all the current non-roofers without turbo's will now be fitting a turbo in order to compensate for the drag :o ;)
As for
@Petrus , I dread to think what the outcome may be ;)
Quote from: AdamR28 on November 30, 2020, 15:05So, two things, when you have a roof:
Most cars, incl. the MR2 roof up, are roughly airfoil shaped with the longer side up.
The airflow is indeed turbulent behind the cabin but also flows downwards. Also, even the turbulent air flows to the rear over the lid. As such the wing indeed sits in more lamina flow the higher it sits relative to the roof but it does not have to be as high as the roof.
Roofless it will still sit in an airflow, just not only laminar, so it will still have negative lift and even direct the airflow.
The lip on the rear of the deck on it´s own primairily provides a tear off ridge.
Under a wing though it also raises the speed under that wing thus increasing the airfoil effect.
As the rear wings can be found at silly low prices I´d say you could simply try.
Now, with a roof, even just a windscreen the so called 3D makes sense but in your case it does not so simple straight will do better.
The jocular observation of turbo needed for drag strongly reminds me of Jeremy Clarkson coming up with the jewel that those with added aero nééd corner faster. I think Kyle Engineers both mentions and explains (refutes) it in a video.
Lest it becomes the next urban myth; on cars negative lift of the airfoil and drag increase are nót necessarily directly related.
I know that running with the hard top on is more than worth the 18kg penalty it gives. The difference in VMax at Knockhill is 101mph vs 106mph, and >1 sec per lap.
Concerning drag: redúced the drag coëfficient and added negative lift
(https://myalbum.com/photo/6C9YVeVeTo3J/1k0.jpg)
Quote from: AJRFulton on November 30, 2020, 19:36I know that running with the hard top on is more than worth the 18kg penalty it gives. The difference in VMax at Knockhill is 101mph vs 106mph, and >1 sec per lap.
That's a good stat, thank you!
Quote from: AdamR28 on November 30, 2020, 20:16Quote from: AJRFulton on November 30, 2020, 19:36I know that running with the hard top on is more than worth the 18kg penalty it gives. The difference in VMax at Knockhill is 101mph vs 106mph, and >1 sec per lap.
That's a good stat, thank you!
VMax is off a Garmin GLO and app data, so it's 10Hz refresh so confident it's accurate enough.
Laptime is a bit harder to compare, as it was done morning session vs afternoon session and had heated up a bit - plus the morning session had the bit of new AR1's. However going by the GPS data the majority of time was lost on the straights.
I wish I had the graphs but it was an old phone and old laptop.
Quote from: AJRFulton on November 30, 2020, 19:36I know that running with the hard top on is more than worth the 18kg penalty it gives. The difference in VMax at Knockhill is 101mph vs 106mph, and >1 sec per lap.
Just for accuracy sake where did the 18kg hardtop weight come from?
I though the last person to weigh it said 25kg but perhaps I am mistaken.
I have one I can weigh if necessary, always good to have this info to hand!
Nearly there now... have been putting off doing the door skin as its a bit of a bugger tbh, but hoping to tackle that tomorrow.
Today's work fitted saw the floor for the final time, a FauxPro mount made and fitted, some more correx gaffer taped in place to enclose the rear and keep water off the ECU, and a few stickers added.
20201201_141421.jpg
In 'got a bit lucky' news, I'd had half an eye on this but not really calculated anything - the rake of the floor is near perfect. 85mm ride height at the front, 95mm in the middle of the car, 100mm just in front of the rear wheels, then kicks up to about 115mm at the very rear of the floor. I made the very rearmost mounts a different style to the rest, so I could use spacers to adjust the height at the back, creating a mild diffuser effect if I wanted.
20201201_160912.jpg
20201201_160404.jpg
Comin'a getcha! ;D
20201201_160350.jpg
Looking great Adam.
I think sterling moss would race it at Le Mans.
Respect.
Quote from: 1979scotte on December 1, 2020, 06:35Quote from: AJRFulton on November 30, 2020, 19:36I know that running with the hard top on is more than worth the 18kg penalty it gives. The difference in VMax at Knockhill is 101mph vs 106mph, and >1 sec per lap.
Just for accuracy sake where did the 18kg hardtop weight come from?
I though the last person to weigh it said 25kg but perhaps I am mistaken.
It is completely skinned. Literally just a shell with polycarb window in it - it may even be lighter than 18kg as it wasn't exactly a scientific method of measurement.
Because it's incorporated into the roll cage, it's a pain in the arse to take off (purely for lack of access as much as anything) - but one sunny track day last summer, off it came. Just as an experiment - As I knew I was going to be doing this, it was literally stand on bathroom scales holding it to see what it weighed in the paddock.
Car was a fair bit slower on the straights using Harrys Lap Timer with a Garmin GLO.
Quote from: AJRFulton on December 2, 2020, 00:07Quote from: 1979scotte on December 1, 2020, 06:35Quote from: AJRFulton on November 30, 2020, 19:36I know that running with the hard top on is more than worth the 18kg penalty it gives. The difference in VMax at Knockhill is 101mph vs 106mph, and >1 sec per lap.
Just for accuracy sake where did the 18kg hardtop weight come from?
I though the last person to weigh it said 25kg but perhaps I am mistaken.
It is completely skinned. Literally just a shell with polycarb window in it - it may even be lighter than 18kg as it wasn't exactly a scientific method of measurement.
Because it's incorporated into the roll cage, it's a pain in the arse to take off (purely for lack of access as much as anything) - but one sunny track day last summer, off it came. Just as an experiment - As I knew I was going to be doing this, it was literally stand on bathroom scales holding it to see what it weighed in the paddock.
Car was a fair bit slower on the straights using Harrys Lap Timer with a Garmin GLO.
Thats fine you've lightened it.
Was just checking.
You know how people are they'll all go round quoting 18kg for a hardtop when its a fair bit more.
Took a while to catch up on a lot of this Adam, you've been going hard at it! Good skills :)
Appreciate this was a few pages back, but good effort on opening up about your mental health too... it affects more us than most people realise and it's all too easy for us to keep it under wraps. Best thing I ever did was speak to someone about the dramas going on in my bonce, it literally changed and probably saved my life.
Quote from: 1979scotte on December 1, 2020, 21:50I think sterling moss would race it at Le Mans.
:)) Perhaps not if he had a better option!
Especially with the piece de ridiculousness that is my gaffer tape and correx roll cage aerofoil.
20201202_103536.jpg
Absolutely daft, but bearing in mind this image...
(https://ozanerhansha.github.io/assets/images/physics/drag_coefficients.png)
If I have got the Cd down from 0.47 to 0.15, just this small appendage has improved the theoretical top speed of the car by around 4mph! (Edit: Cocked up the maths, it's more like 1mph, ha).
More silly testing - this time with the airline. Again, obviously not that close to real world as the flow of air is quite 'defined', but at least gives a visual of the sort of things that will be going on...
Airflow over the passenger side 'windscreen'. This is less than 1" tall.
Drivers side, around 2.5" high:
The lip on the bonnet duct / vent:
The exit from the bonnet duct, with the compressor generally squirting through the hole in the front bumper:
And finally the roll cage - you can see the completely stalled (ie. drag) air behind the 'open' bar, and a nice attached airflow over the aerofoil:
Quote from: AdamR28 on December 2, 2020, 11:50More silly testing -
Very far from, Adam.
It is totally realistic representation of what réally happens.
I think it awesome.
It is also far from negligable.
Thanks for the emperical confirmation/illustration of the science.
p.s. mán all that caffeïne stimulated mental effort to shave of 2 kilo there, a half here, etcetera and you chuch some 150 more like thát, phew.
No caffeine must be the key ;)
The car is now on the trailer ready for Saturday! This is a bit of a unique feeling - I keep thinking it's Friday, because I'm never done in plenty of time.
Sorted alignment last night, kept it 'safe' to start with:
thumbnail_20201203_102804.jpg
Found a fibreglass roofing panel on the car park at work a few weeks back following a particularly windy night. That'll come in handy I thought, and it has - as a little lip to the boot lid (well, it's attached to the bumper) in an attempt to reduce some drag / wake.
thumbnail_20201203_114421.jpg
Stuck some Tempilaq on the left hand rotors (for anyone who likes this sort of thing, I've just seen a bargain on eBay: https://www.ebay.co.uk/itm/Tempil-Tempilaq-Temperature-Indicating-Liquid-All-Temperatures-12-2oz-Bottles/174054107054?hash=item28866ee7ae:g:PvwAAOSwCXVdmG7x).
Why only the left hand side? On UK circuits, 66% of the turns are right handed, so with trail braking the left hand brakes see more use than the right, and I actually experience faster pad wear on the left hand side of the car.
The two colours 'indicate' at around 500'C and 600'C - if I'm hitting these sort of temps then I'll be running into fast pad wear and may need something more beefy. However, looking at the forecast, I don't think that'll be a problem on Saturday...
thumbnail_20201203_115713.jpg
Rolled him / her / it outside for a photoshoot.
The eagle-eyed will spot the 'unte' on the rear bumper - I have the M, the R and the 2 ready to go back on as well but can't find any double sided sticky foam pads! Maybe the ones I've ordered will arrive tomorrow...
thumbnail_20201203_120952.jpg
That front end. Not. Pretty.
thumbnail_20201203_121003.jpg
(https://sealifetrust.azureedge.net/cache/4/8/d/2/9/1/48d29166c1b4fed141160b815e640542892731f2.jpg)
thumbnail_20201203_121014.jpg
thumbnail_20201203_121037.jpg
thumbnail_20201203_121108.jpg
thumbnail_20201203_121123.jpg
I think it looks hilarous with the random bit of wood hanging out the back :)) On that note I am wondering if the area under the exhaust might see some 'adverse temperatures', specifically after coming in following a session. I'm not concerned while on track due to the NACA duct in the floor, but it may need some help in the form of a polished aluminium sheet, spaced away from the ply by a few mil. I will try to remember to knock one of these up and pre-drill it, so I can screw into place on Saturday if necessary.
Got a garage booked (hopefully the same one as
@Maurici ) and really looking forward to some track time!
Upon emptying the trailer I was faced with this. I obviously had 'some' ideas pre-aero-learning, but my brain is looking at things very differently now...
thumbnail_20201203_130258.jpg
I'm picturing the sniggers from the snobs in their Caterfields and Porsches when you roll up. For them sniggers to turn into shock when you're pushing them aside out on track.
What tyres and pads are you running Adam?
That was standard with the orignal Munter yep, so hoping it will be the same again!
Apec pads and Falken ZE914 tyres. Only the best. Snigger.
Quote from: AdamR28 on December 3, 2020, 17:24That was standard with the orignal Munter yep, so hoping it will be the same again!
Apec pads and Falken ZE914 tyres. Only the best. Snigger.
Nah you'll be sound with them on such a light car. I've had the 914s on my Celica 190, and just fitted a set of FK510's to my F30 330d. Falken are really underrated tyres.
Quote from: JB21 on December 3, 2020, 17:50Quote from: AdamR28 on December 3, 2020, 17:24That was standard with the orignal Munter yep, so hoping it will be the same again!
Apec pads and Falken ZE914 tyres. Only the best. Snigger.
Nah you'll be sound with them on such a light car. I've had the 914s on my Celica 190, and just fitted a set of FK510's to my F30 330d. Falken are really underrated tyres.
They are decent tyres (especially in the wet), but if I'm guessing correctly, they've been borrowed from the bucket and are a good few years old now. They certainly won't be in any way sticky!
They're new uns, as I got hold of some 14" wheels. Have used the old version on track before and liked them (Hi
@B.RAD !). It was a toss up between these and TR1s, so may try the Toyos next time.
Well hello! Loving the thread mate, a thoroughly good read full of interesting insight, upgrades and tech thoughts. Can't wait to have a go in Mr Poo! (That sounds weird)
Those falkens are mega. Had them on my Westfield, 520kgs and 226bhp and they were great, very predictable and communicative (if not with the ultimate grip levels).
Gutted I can't be at Oulton with you but I'm looking forward to the updates 👍
The 914 is no longer made in '2' sizes, their model now is the ZE310. I cannot comment on them for track, but they're pretty good on a road car. Secure in the wet.
The 914s are so good in the wet. I always wondered why people said to exercise caution on wet roads in a MK3, as the bucket always felt rock solid even in monsoon weather.
I did have the older Toyo's (T1R I think) on the front of another middy, and they were pretty shocking! The crap budget tyres on the back had so much more grip than them it would understeer at sensible speeds.
Yes Lee, I agree about the 914's, great tyres in my book! ;D
You wanna try the FK510's, they have 90% of the performance of Michelin's PS4 at half the price. Epic tyre for the money.
Even my 330d with 560nm of torque struggles to break traction in the wet.
Just a shame they only make them in 17" upwards.
did you do the track day?
Yep! And mostly all good. Have vids, pics and stuff to write up when I can.
Oulton Park 5th December – First Outing!(Note after having written this out – it's long, and maybe not that coherent as it was done in a few chunks.)
TL:DR: Car didn't break, is fast, is a lot of fun, oversteers a lot. Happy days!
Having not been on track for a while, and having a new toy to play with, I was pretty excited about this one. That excitement was slightly tempered by the fact that, in the past, I have given myself a hard time if things don't go 100% perfectly. Combined with December usually being absolutely manic at work, meaning high stress levels and lack of sleep, it meant things had the potential of going terribly wrong...
I've been reading Adrian Newey's 'How to Build A Car' book over the last few weeks, and while being an interesting insight into the world of F1, his single-mindedness and level of focus also struck a chord. Perhaps more importantly for me, the book also mentions his 'failures' – such as misunderstanding certain aspects of the car from time to time, and 'that' incident on 1st May 1994, for which he still feels partly responsible as one of the senior engineers on the FW16.
The book proved to me that even the very best make mistakes, so I could cut myself some slack and not everything had to go perfectly with a freshly-built car.
The weather was as you'd expect in the North of England in December – cold and wet. On the floor at least; we managed to escape rain for 99% of the day, and the track even ended up with most of a dry-ish line by the time dusk fell. It was, however, mostly covered in a mixture of cement dust and the contents of someone's sump by this point – this had meant a track closure of nearly an hour mid-afternoon. I guess this was the Yin to the morning's Yang, where everything went beautifully and there were no stoppages at all, despite the super slippery near-zero conditions and murky visibility.
A very good friend,
@Maurici (my 'race boyfriend' – his terminology, not mine), came along in his mx-engineinwrongplace – meaning a pair of blue, RWD, Japanese sports cars with 1.8 litre engines and about 140bhp – but obviously slightly different!
(http://www.tartybikes.co.uk/car/munter2/startofday.jpeg)
I had a new FauxPro to get used to having lost my GoPro (I hoped it would immediately turn up having bought the new camera, which it should have done according to Sod's law, but it seems Sod is on holiday at the moment), and I cocked up the set up and it didn't record for the first session. This was a bit of a shame but not the end of the world.
First impressions:
1) This is a quick little car (nothing came past – all morning, in fact, and only one car all day! – and all manner of expensive stuff was easily dispatched).
2) The aero works (properly shat myself the first time I entered Island bend, and it oversteered quite strongly. And again at Druids. Yet understeer through the two low speed chicanes unless you meter it with the brakes.).
Here's a still from a video I took of Maurici heading past the pits... not on the brakes at this point, and the front of the car looks very low! There's also a lot of 'squirt' coming off the front corners of the car, and a reasonable amount of spray being sucked up into the air, as shown by the water.
(http://www.tartybikes.co.uk/car/munter2/lowfront.jpg)
(http://www.tartybikes.co.uk/car/munter2/spray.jpg)
3) Driving position and ergonomics are almost spot on (ended up removing the foam pad on the headrest, as that 10mm was too thick and pushed my helmet forward a touch).
Entering the garage after the first session I was feeling pretty chuffed. All the stuff I'd done seemed to be working just fine – water temp was stable proving the ducting works, the engine pulls hard to the red line proving the exhaust works (and sounds awesome!), the car drives straight and true (alignment all good), the mechanical handling / grip was excellent with tons of feedback (armfuls of controllable sliding about when wanted, but still fast enough to overtake everything), the 'rear view mirror' did the job perfectly, brakes not optimal – but fine, with no fade and enough feel.
A quick check around the car revealed that everything was still stuck on, I had burned about 200ml of oil (haha), next to bugger all fuel (started with nearly a full tank) and the brakes were getting to surprisingly high temps.
Front brakes: The green paint burns off at 500 degrees, the pink at 600.
(http://www.tartybikes.co.uk/car/munter2/frontdisc.jpg)
Rear brakes:
(http://www.tartybikes.co.uk/car/munter2/reardisc.jpg)
I've said it before, but I'll say it again – these are Apec pads. Cheapo road pads from the local motor factor - you can do a complete car for under £40 – yet they work really, really well. 600 degrees is a fairly significant amount of brake temp, just have a look at what 'proper' brake pads are rated to.
(For reference, 500'C = 930'F, 600'C = 1110'F)
(http://www.tartybikes.co.uk/car/munter2/ferodopads.jpg)
(http://www.tartybikes.co.uk/car/munter2/hawkpads.jpg)
(http://www.tartybikes.co.uk/car/munter2/wilwoodpads.gif)
I'm unsure how well the Apecs will hang on when it's properly dry and I'm really pushing on, but I've never had these fade on me (other than 'green fade' when bedding in, of course) and have done plenty of track days and racing with them fitted to heavier cars with smaller brakes. They just tend to wear faster if they do get too hot, which produces tapered wear, and associated mushy brake pedal – which is enough warning to change them. A spare set in the van, changed over in ~10 minutes, job done.
I managed to get the FauxPro sorted for the rest of the day, but annoyingly even when you plug the external mic in the internal mic keeps working – so the sound is a bit crap. Maurici found a way to stop this by drilling the camera, destroying the internal mic – but I figured that was best done in the workshop than in the paddock with cold hands!
Speaking of – Maurici took the car out, got settled in the first lap, tried to push on a bit the second, stuck it sideways a lot, then came straight back in and declared it was too much of a handful for him. He is one of the people I would say knows how to handle a car – and the video below proves it (see 3:50 and 4:55 for proof) – so for him to agree with me that the balance wasn't there meant I should probably try and do something about it!
I went for the simple options: more pressure in the front tyres, and a bit of toe in up front. With hindsight, I could have disconnected the rear ARB as well / instead, but for now lets explain what I did do.
With the fraction of static toe out the car had initially, this means the inside front wheel creates scrub at initial turn in, resulting in an oversteer torque on the car. Changing that to toe in, means the torque on the car is then trying to make it understeer, settling down the initial phase of the corner.
I feel a diagram would be useful here...
The cross in the circle represents the centre of mass of the car, the point around which all forces operate. The arrows represent forces – straight ones are scrub due to the tyre pointing in a different direction to the car's motion, curved ones are the resulting rotation.
(http://www.tartybikes.co.uk/car/munter2/toe.jpg)
Now, the MR2 uses almost 100% Ackerman steering, meaning the inside front wheel turns more than the outside (for the same amount of steering lock). So when combined with toe out, this effect is magnified. With slight static toe in, this reduces the above effect at the very start of the turn-in phase, helping to keep the car settled.
The tyre pressure adjustment – this is a huge area and I am not one of the most qualified to 'lecture' about it, but below is my understanding of parts of the puzzle.
People do this sort of thing all the time without realising what is actually going on. 'Oh I've got understeer so I need more front grip and I'll reduce the front tyre pressure to give a bigger footprint'. Weellllll yes, part of the story. Ish.
Increasing tyre pressure effectively 'props up' the carcass of the tyre more, with three significant results: The effective spring rate of the tyre has increased, slip angle is generated more quickly, and optimum lateral load is generated at smaller slip angles.
Slip angle is the difference in direction between where the contact patch of the tyre is pointing and where the wheel is pointing, in degrees. The tyre physically twists up when you turn the steering wheel (it also happens at the rear, or else you wouldn't go round the corner, but we'll leave that one for now!).
Imagine grabbing a 1" square chunk of solid rubber, about 4" long, and pushing it onto the surface of a desk. Now, twist with your hand. The rubber will deform to a certain amount / angle, then the 'footprint' will start to rotate when it can't stick any more. This is what your tyres do – load is applied to them vertically, you twist them, until they can't stick any more. You can then imagine if your rubber is firmer, it will twist less before the footprint starts to rotate.
Road tyres generate optimum lateral grip at larger slip angles than track tyres – and from the above test, we can see why. The road tyre has softer carcass, so twists more. By adding tyre pressure, this stiffens the carcass, and you get your optimal grip at reduced slip angles. The slip angle also builds more quickly because of less twist in the tyre, so you get your optimal grip 'appearing' more quickly.
From the above, increasing tyre pressure will actually increase the rate / speed at which grip builds at initial turn in. It certainly gives the driver more feedback. And this is why lowering tyre pressure CAN be the wrong way to go if you need more grip, depending on what phase of the corner you need it...
So... what about mid corner? There is an optimal pressure at which the tyre will give you the most grip, which depends on a huge range of things. It can, however, be determined with a tyre temperature probe (not IR gun, which only takes the surface temp). Deviating from this either way will give you less grip.
Not knowing the optimal tyre pressure for my car on this day in these conditions, meant I'd have to completely guess at the correct value. So I didn't. But why, if increasing pressure has been shown above to build grip more quickly on initial turn in, and more front grip would give more oversteer, did I go higher with the front pressures?
The change in spring rate is important – 1psi will change the spring rate of the tyre by ~25lbs/in in most cases. On a softly sprung car, on road tyres - like mine - the deviation in tyre spring rate from pressure changes can have a huge input on the overall handling of the car.
This is another discussion for another day, but in short – if you stiffen one end of the car, that end will 'lose' grip relative to the other end of the car. It's why ARB adjustments work for adjusting under / oversteer balance.
The actual springs are only 106lbs/in, front ARB probably around the same again, and while I don't have data for the Falken ZE310 (obviously) I can see from a Hoosier FSAE (Formula Student) slick spec sheet that theirs are approx. 530lbs/in at 10psi, going up to 740lbs/in at 18psi. These tyres are designed for a 250kg car, and having had hold of a set before, I can say that the sidewalls are pretty supple – not far from a road tyre.
Adding 8psi to the front tyres on Saturday massively increased (as a percentage) the front spring rate, thus giving the front axle - as a whole system – a higher spring rate, and thus reduced front grip. And it reduced slip angle needed to get the car to turn in, and increased the rate at which the slip angle built. No wonder I like high pressures on track with road tyres...
To put some maths on that, because I love maths...
'Actual' spring rate: 106lbs/in
ARB spring rate: 100lbs/in (guessestimate – haven't measured an OE ARB yet)
Approx tyre spring rate at original pressure: 890lbs/in
Approx tyre spring rate with +8psi: 1190lbs/in
Increase in total spring rate from increasing tyre pressure: Going from 1096lbs/in to 1296lbs/in = 18%
(And the front of the car was scrubbing / grounding out under hard braking when hitting a certain bump, so I figured trying to keep it off the deck wasn't a bad idea - sometimes practical considerations can be just as critical as theoretical ones!)
Just for fun – lets do the same with coilovers, and a stiff ARB.
'Actual' spring rate: 270lbs/in (a 5kg/mm spring, such as MeisterR coilovers)
ARB spring rate: 180lbs/in (guessestimate – I haven't measured a Whiteline, for example)
Total spring rate before / after tyre pressure change: 1340lbs/in to 1540lbs/in = 15% change. Add in a stiffer tyre to start with (as most with coilovers and uprated ARB-shod cars would have), you can see the tyre pressure change isn't as significant as with a softly-sprung and squishy-tyred car.
Anyway, 'blindly' lowering or raising tyre pressure may or may not give you more or less grip. What it will give you is a change in the slip angle that generates the optimum cornering load, how quickly the tyre reaches the optimum slip angle, and the spring rate of the tyres (and thus axle) that you have played with. As they often say, a little knowledge is more dangerous than none at all (and I certainly don't know it all!) – but in general the old 'I'll lower pressures to add more grip' does work, just for different reasons than you think.
Part 2 to follow...
Now, here's something I get all the time – coming up behind a 'normal' car (eg. one with all the major bits still attached where the manufacturer intended) in my shitter, the driver in front assumes it's got buttloads of power because it looks crap, so they don't move over and keep the throttle buried on the next straight. The ensuing drag race is usually frustrating (and I lose, ha), but today it helped give some sort of indication of engine health.
Stuff Mr Poo is a bit faster than, in a straight up drag race:
- EP3 Civic: 197bhp, 1280kg (with driver) = 154bhp/ton
- 172 Cup: 170bhp, 1100kg (stripped out, cage, driver and passenger) = 155bhp/ton
Stuff a bit faster than Mr Poo, in a straight up drag race:
- E46 M3: 343bhp, 1650kg (with driver) = 208bhp/ton
It appears The MunteR2 sits pretty much in between these two 'sets' of cars. Obviously there are other factors involved, so this isn't all that accurate, but...
- Mr Poo: XXXbhp, 840kg (with fuel and driver) = approx. 180bhp/ton, therefore approx 150bhp (180 / 0.84 = 151).
Now obviously gearing and aero / drag plays a part, but I'm confident my 1ZZ 2-stroke is not putting out less than 140bhp. Happy days.
The reason I say 2-stroke, is that the thing used nearly a litre of oil, but only about 30 litres of fuel. This was really quite confusing. Not the oil consumption, obviously, but using such little fuel. I've still got two full jerry cans sat in the van! I think I need to get an AFR gauge in there to check it's running safely...
Now moving on from theory, to practice.
Three bolts holding the steering wheel on, he said. That'll be fine, he said.
Unless two of them drop out. Gulp.
In what is probably one of the scariest moments I've had on track – not helped by that Caterham bullying past at a wholly unsuitable place and time - this happened.
Now obviously there are worse times and places for the steering wheel to become non-functional, but it's not ideal. I did, however, get away with it.
I had half-intended to swap the steering wheel over to a smaller one pre-trackday, so I hadn't tightened the bolts properly, just nipped into place. Also turns out the bolts didn't QUITE reach the nylon part of the nut.
Lesson well and truly learned. However, even Adrian Newey isn't infallible.
One of the bolts was fished out of the cockpit, a spare dug out from the back of the van, 2 new nuts fitted, and out we go again.
I also decided to tweak the angle of the rear part of the floor, giving it a smidge more 'kick up' at the rear. This in theory should add some downforce (or reduced lift, at least) to the rear of the car. It seemed better - both in the car and on the video - but not sure if that was me driving differently, trying to keep speed going rather than just sliding about, or it actually had an effect.
The final session was great – lots of 'the usual suspects' kicking about, track prepped Clios, Civics, MX5s, various BMWs. All those sorts of cars that have been 'developed' for track days, driven by experienced drivers. You know, the ones that are actually reliable enough to still be running at the end, owned by people who haven't given up because it was a bit slippy earlier in the day, who know the final session is often 'the one'. The track was even nearly dry, ish.
If I'd have had the datalogger running, which I didn't obviously, it would have showed a best lap around 2:10. Which, considering none of the laps were clear and the track wasn't dry, is better than anticipated.
Here's a sketch of some data traces I did from memory / feel, because the datalogger wasn't running, obviously.
(Bugger, forgot to send these over to myself last night - will upload at another point!)
(https://www.tartybikes.co.uk/car/munter2/oultonpark_map.gif)
This is Munter (in the bone dry on proper tyres) vs MunteR2. The main things that stick out are:
- The wet bits of track really cause a huge drop in apex speed - 20mph through Island bend!
- MunteR2 is clearly a lot faster in a straight line, gaining around a second on each straight, and a huge gap in the drag up Clay Hill.
And just for fun, here's MunteR2 vs Lobster (my Westfield with the bike engine, on silly skinny road tyres and with terrible aero, hence not really having higher apex speeds despite the low weight).
(Again forgot to send this, will do it later)
So. What's next? Well, here's the to-do list. Aims and intended routes.
- Sort the aero balance. This was perhaps the first thing that struck me as 'awkward' about the car, and certainly Maurici agreed! Big Gay Wings (BGWs) are not really my style, and they do cause additional drag, so that leads me to playing with the floor...
My recent aerodynamics research revealed that there can be some significant gains from a proper diffuser. At the moment it doesn't have enough angle, and there will be air spilling in from the sides (high pressure down the sides of the car vs low pressure under the car = the air tries to go from an area of high to low pressure, reducing whatever effect it is having).
So I had a nosey for some documents which may assist with design, and stumbled across this absolute gem: https://www.racetechmag.com/2017/08/willem-toet-explains-motorsport-diffusers/
This gives me pretty much all the info I need to get designing and (hopefully) create something that will create downforce.
I do need to be a little careful of the exhaust proximity to the floor though, as shown it below it was slightly affected at the weekend...
(https://www.tartybikes.co.uk/car/munter2/burntfloor.jpg)
As part of this job, I will raise the front of the floor by 10mm or so. This will reduce front downforce but therefore aid balance at higher speeds. Plus, it will help to stop it bottoming (especially once a passenger is in!). It was only the deflectors in front of the front wheels, but having them scrubbing as I hit a bump while braking on the way into Island, and all the way through Shell when the car is fully loaded up, was a little off-putting. If that still doesn't work, I can pack the bump stops or fit longer or stiffer ones.
Playing with ground effect in this way, especially with soft suspension, I'll have to be a little careful not to go too 'extreme' else a change in ride height can totally cock up any downforce – eg. hitting a big bump mid corner could stall the rear diffuser and lose grip... (IF any of it works!)
Another note on this subject, the rear of the car has a really 'turbulent' look about the dirt on it. I am wondering if the floor exit being 'in front of' the rear of the car hasn't helped in this respect, so extending the floor into a diffuser and having it exiting behind the bumper should help.
(https://www.tartybikes.co.uk/car/munter2/reardirt.jpg)
- Tweak the brakes. The front brakes are doing all of the work at the moment (check the wheel dust on the side-on photo below). With the car being so rear-weighted, there will be a gain – both in braking performance and pad life – if I can shift that rearwards. I need to do some maths surrounding line pressures, but it looks like I'll add the bias valve into the front circuit. I appreciate this isn't the normal place for it to go – but – this isn't a normal car and I'm not a normal kinda guy. The brakes also could do with a bleed, I always find there's bits of air dislodged after proper use, and the pedal feels that way too.
- Add extra rear ARB adjustment. I'm going to weld a bit of bar onto the ends of the rear ARB, so it has more adjustment in the 'soft' direction. Another handling balance tool for next time, if necessary.
- Attempt to keep air out of the passenger compartment. Now this is a funny one which confused me at first. The panel behind the seat, which is designed to keep air out from the area where the roof would normally bolt (which would end up like a parachute), is held in with gaffer tape as before. This time though, the gaffer tape has started to rip, indicating it's taking a fair amount of force...
(https://www.tartybikes.co.uk/car/munter2/leftgaffer.jpg)
(https://www.tartybikes.co.uk/car/munter2/rightgaffer.jpg)
With more thought this makes sense: 1) the levels of the front and rear openings to the cockpit on the MR2 are totally different to the MX5 – the MX5 has a higher front and a lower rear, the MR2 is the other way round.
(https://www.tartybikes.co.uk/car/mun1.jpg)
2) I'm now firing a heck of a lot more air over the scuttle thanks to that big duct from the front bumper through the radiator. This has to go somewhere – and it appears that is into the cockpit and thus into that rear panel.
I'm thinking of some sort of additional deflector mounted to the bonnet, firing the ducted air up, sideways, or a combination of both. Needs more thought.
(https://www.tartybikes.co.uk/car/munter2/duct.jpg)
On that note, the bonnet – despite being single-skinned and pretty floppy – barely bobs around at all even at 100mph+, which proves there Is very little air entering the front of the car. Happy days.
- Probably more stuff I haven't identified yet.
- Oh yeah, that stupid aerofoil shape on the roll hoop? Was ok for most of the day, until the track dried and top speeds got over 100mph. Then it just started flapping about all over the shop, so much that it almost deafened me and I was scared it would fall off. So I ripped it off. I have a tentative plan involving some 3D printed wing 'chords' and thin sheets of Lexan, so let's see where that goes.
I've now booked Donington for 16th Jan, and already looking forward to seeing if my tweaks work as intended!
(https://www.tartybikes.co.uk/car/munter2/sunset.jpg)
(https://www.tartybikes.co.uk/car/munter2/frontgarage.jpg)
And the reason I used white correx for the scuttle? It acts as a board to write stuff on!
(https://www.tartybikes.co.uk/car/munter2/kills.jpg)
Thanks for the information and entertainment Adam.
Will need to mull over the former a ´bit´!!!!
Can you fit a ´tonneau´ cover over the passenger tub?
A silly big wing may not suit your style; it does work a treat though.
Lóve the whiteboard kill tally. Something to translate to car silhouettes on the quarter panel ;-)
Most of that (like the wind/rain) went over my head but its seems to have gone very well for a first drive!
The videos were more interesting than most track day videos too, feels like you are in the car for some reason....
I hope you were wearing your brown pants when the wheel started to fall off.
I was also going to ask about a tonneau cover. In the spirit of the car, could you glue some kitchen foil on the difuser under the exhaust?
(Still think it would look better all one, very bright, colour!).
Congratulations.
Nice one Adam didn't understand most of it but I read it all.
Got the datalogger info now:
Here's a sketch of some data traces I did from memory / feel, because the datalogger wasn't running, obviously.
mvm2.jpg
(https://www.tartybikes.co.uk/car/munter2/oultonpark_map.gif)
This is Munter (Blue trace - in the bone dry on proper tyres) vs MunteR2 (red trace, session at the end of the video). The main things that stick out are:
- The wet bits of track really cause a huge drop in apex speed - 20mph through Island bend! (Around 4300 feet, looking along the bottom of the image - where I have plonked the white vertical line). At this point, looking down the far left of the image, you can then see that the red trace (MunteR2) is pulling 0.86 lateral g, and the blue trace (original Munter) is pulling 1.17g. We can assume that they are taking the same radius, therefore this explains the difference in apex speed - 76.8 vs 96.6mph. Heading right down the bottom, at this point in the lap the red trace is 1.454s behind the blue one, and this steadily climbs through the lap. This is called the lap delta.
- MunteR2 is clearly a lot faster in a straight line, gaining around a second on each straight from looking at the delta (the red line drops down slightly as it goes along), and a huge speed gap in the drag over Hilltop (7500 feet) and up Clay Hill (10000 feet along).
- Druids (11000 feet) is also really slow compared, because it stayed wet.
- Cascades (2300 feet) dried out sufficiently for corner speeds to be matched.
Looking into the data more, I drove a 2:07.8 'continuous' lap (from Shell Hairpin to Shell Hairpin), and the best theoretical (puts together all the best sectors) on the day was a 2:04.1.
So, with all said and done, I think this car is capable of a 2.00 minute lap in the dry, even in current guise.
And just for fun, here's 'old' Munter (Blue trace - chose this one because it was also dry) vs Lobster (Red trace, my Westfield with the bike engine, on silly skinny road tyres and with terrible aero, hence not really having higher apex speeds despite the low weight).
lobvmunt.jpg
You can see the insane differences in acceleration from the angle of lines, which means massive differences in top speed - up to 25mph at points.
Another stark difference in the traces: With a low-powered car, the key is to maintain speed; so you brake later, rolling through the apex faster, and you can do this because you don't have all that excess power ready and waiting to spin up the rear wheels when you put your foot down.
The opposite of that is what I do in the Westfield - I am slowing down to minimum speed earlier, and in some cases a lower minimum speed, in order to get the car fully rotated earlier and take advantage of that extra acceleration, which is the optimum way to end up with a higher speed at the end of the straight.
Just looking at your speed graph and how smooth it is I can see you don't brake as hard as me, therefore carry more speed through the corners. Something i definitely need to learn.
Below you can see mine, lots of sharp drop offs where I'm braking to much. No idea what happend at shell, must have lost GPS.
This day/lap was in the middle of summer with temps around 25°, roof off, on AR1's with bluestuff pads front, yellowstuff pads rear . Its actually the lap before the engine went pop 🙄
(https://i.postimg.cc/5tgNswZr/Screenshot-20201208-171243-Race-Chrono.jpg)
(https://i.postimg.cc/DZVkdmzN/Screenshot-20201208-171330-Race-Chrono.jpg)
Very interesting Adam, thanks for sharing it. You have driven a 2 on a track before though, yes?
Gary
Quote from: Gaz mr-s on December 8, 2020, 22:23Very interesting Adam, thanks for sharing it. You have driven a 2 on a track before though, yes?
Gary
Very welcome!
Ah yes, completely forgot about the 3 Sisters evening. Oops!
Quote from: AdamR28 on December 9, 2020, 09:15Ah yes, completely forgot about the 3 Sisters evening. Oops!
Right..... so has the flat undertray increased your front-end grip, or is it in combination with the splitter?
None of this is guaranteed, and slightly hard to figure out due to so many other changes, but here are my feelings...
- The splitter itself does next to nothing. I intended it that way. I didn't want something huge sticking out for both practical (eg. not smacking it on stuff) and cosmetic reasons.
- The floor, however, is a massive gain to both drag reduction and either generating downforce or reducing lift. I'm not sure if it actually *makes* downforce, but my gut feel is that it does, from how the car feels and that photo of it heading down the straight. It definitely reduces lift though.
This is explained well in the video below:
I think the MR2 is a perfectly-suited car for this modification, due to the engine location and lack of hot stuff running all the way down the underside of the car.
So, that's what the Nappies are doing? ;) ;)
The front nappies will be doing a little bit of lift reduction yes, but their shape and stiffness isn't good enough to produce downforce.
At the rear... It's more a cover to keep spray out than anything.
Quote from: AdamR28 on December 9, 2020, 10:41I'm not sure if it actually *makes* downforce, but my gut feel is that it does, from how the car feels and that photo of it heading down the straight. It definitely reduces lift though.
The whole car is shaped like an airfoil and moving forward through air creates less air pressure above than under. This results in a force opposed to gravity. Call it anything you like. Lift is most common.
The air passing underneath the car is affected by several other aspects: The road surface, the pofile of the underside, how the frontal air is directed, how the air passing through the radiator is directed, how air is ´extracted´ at the rear or not, the rake of the car etc.
A flat underside will reduce turbulence under the car thus speed up the air flow thus deminish the airfoil effect. As the latter is most commonly called lift, the effect of the flat floor is most accurately dubbed negative lift.
Basically most things done to the underside are counteracting the airfoil effect, thus negating the lift.
Now take rake. Thát creates a pressure drop by increasing more volume towards the rear of the car and although the resulting force counteracts the lift, it is different from the airfoil effect and you could dub it downforce.
Seems semantics but it does help understand what is happening.
The air vents in the bonnet are tricky ones. Although they reduce the amount of air pushed under the car by the pressure wave in front, thus reducing pressure under the car, it also affects the two air flows, thus affecting the airfoil effect. This may go either way although the effect of less pressure under is most likely the greatest.
All in all an übercool subject imo and I reallyREALLY appreciate the illustrative emperical efforts by Adam.
@nappies that is both yes and no. Just look under the front: There is a gaping hole allowing the air passing through the front to go underneath the car. This is already a totally turbulent flow. Imo the rear nappies are foremostly intended to keep the noise down.
What Adam has done is create a vent abóve, allowing him to close, smoothen the bottom and thát makes a lot of difference.
As I write; übercool.
Quote from: JB21 on December 8, 2020, 17:28Just looking at your speed graph and how smooth it is I can see you don't brake as hard as me, therefore carry more speed through the corners. Something i definitely need to learn.
Below you can see mine, lots of sharp drop offs where I'm braking to much.
I am actually generally pretty poor in terms of finding maximum braking. Know all the theory, but struggle to put it into practice! I tried to be last of the late brakers at Donington at a race meeting once - ended up through the gravel a couple of times. It is something I'm aware of and working on, but I find having a small margin for error comforting, especially on a track day. There are lots of people who *can* brake later than me, but this isn't the full picture so I've spent my time learning / researching other phases of the corner.
You need accurate datalogging equipment to see the subtle differences in braking traces. Something that has an accelerometer rather than using GPS speed. In general though, braking as hard as the car will allow is always a good thing, with a caveat - the driver must have the car under full control at the entry phase of the corner.
Something else that makes a difference is the suspension setup. If you just literally stamp on the pedal, the brakes will lock in any car (well, perhaps not something with shedloads of downforce) because there's not enough vertical load on the front tyres yet to allow the tyre contact patch to create enough torque to overcome the braking torque from the pads / disc.
It therefore follows that a stiff car will allow you to get to full braking effort more quickly, because it transfers weight forwards more quickly.
With a moderately stiff car, you can get from full throttle to full braking in around 0.3-0.35s. With the MunteR2 being on a soft setup, this is going to be more like 0.5s. At 100mph, that means having to start braking nearly 10m earlier, and the shape of the speed trace will be more 'rounded' at the tops of the peaks. Once you're on the brakes fully though, the steepness of the speed trace is unaffected, and in some cases can remain steeper because the car will be less upset by bumps on a softer setup.
Getting to corner entry phase, coming OFF the brakes is very important. Jackie Stewart is quoted as saying it's the hardest thing to learn. Here you are aiming to actually steer the car using the brakes, rather than the steering wheel. Turning the steering wheel introduces a slip angle to the tyres, which creates scrub - the tyres pointing one way and the car travelling another. This scrub reduces your speed.
If you can 'hint' the car into the corner (using a very small steering input) and then use weight transfer - via the brakes on entry - to get / keep more weight onto the nose, this will increase grip at the front (and thus reducing grip at the rear) and the car will keep rotating into the corner, with very little steering lock on.
On this note, if you jump off the brakes just before you turn the car in, or as you are turning in, this releases weight - and therefore grip - from the front wheels, just when you need it. Understeer. Safe, but slow. So, releasing the brakes smoothly is really important. Again with accurate datalogging, you can see what's going on in this area.
The holy grail is zero steering lock, with the car physically rotating around its centre of mass all the way through the corner, rather than being steered through, as the brakes bleed off and the power feeds in just as smoothly. In reality, what's possible for mere mortals is a series of steering corrections all the way through, the car transitioning from 'steering' to 'oversteer' conditions (and hitting everywhere in between) while you shuffle the steering wheel and increase and decrease pressure on each of the pedals, depending on which phase of the corner you're in.
The start of the main video above, with all the slides, is me trying to hit that stage, but just overcooking it slightly. Too much oversteer is also slow, as we all know, because that scrub I talked about is there in vast quantities - but you have to get the car out of shape a little bit for it to get close to its potential.
It therefore follows that, to hunt for 'the holy grail', you need to be comfortable with the car moving about under you... And you also need to be able instigate that consistently, with control; rather than simply reacting to what the car is doing. Many people never reach this stage for the reasons I'm about to explain below.
It is really important to consider the car and the driver as one. Bolting go-faster bits to the car does make the "car & driver package" faster immediately, but the car is then harder to drive and the driver will never get as close to the potential of the car as they would had they learned in a soft car. If you have a car that is now 5% faster because of the latest go-faster bits, but the driver can only exploit 80% of that performance, it will end up slower than a standard car with 90% of the potential used.
This is why I am a HUGE advocate of learning to drive on track in a soft car, with low power on cr@p tyres. The above 'system' happens at a much reduced speed (both in mph and the rotation of the car) and thus gives the driver more time to 'play' on the edge of grip. Think underside of spoon rather than sharp edge of knife. A faster car means faster corner entry with less time to react, a stiffer and grippier car means the whole thing transitions from grip to slip in much reduced time. If the driver hasn't learned the 'signs' in the slower, softer car, he or she will never learn them in the faster / grippier car because it will be scary when the car gets out of shape. This means they always drive well within the potential of the car, to avoid said scary moments.
That ended up a lot longer than I anticipated, but hopefully it all makes sense and may help a few people!
@AdamR28 The last part of your essay reminds me of something tiff said when he was doing a test on track for 5th gear.
He basically past a radical in a Mx/124. He observed that the driver was a novice under instruction and why were they trying to learn to drive on track in something that was practically a race car. They should be driving this he said.
Makes perfect sense.
I'm defo in the camp of reacting to what the car does, instead of instigating the movement. Saying that I feel I can react pretty well but I know I have a long road ahead to be one with the car.
This is my first ever rear wheel track car, and road car for that matter so jumping straight into a super stiff MR2 2zz conversion with its MR layout, short wheel base and no driver aids apart from ABS was a real baptism of fire.
Would be good for you to come out with me on track to observe my current technique, then come in to the pits to discuss where I can improve. I sat come in to the pits as the car is that loud you can't hear a bloody thing when someone is speaking, lol.
Quote from: AdamR28 on December 11, 2020, 12:37This is why I am a HUGE advocate of learning to drive on track in a soft car, with low power on cr@p tyres.
Why I left the newly bought MR on cr@p tyres with the winter coming up.
About braking you are só spot on.
When racing motorcycles I was one of the latest brakers yet always smóóthly applied them so the bike could load the front. Just grabbing a handfull is a sure way to dump it on the tarmac. Also less brusque applying gives you feel and the two allow you to brake hárder thus later even though you initiate the proces earlier.
Same thing un-braking; letting go unsettles the bike and same thing the car.
Quote from: JB21 on December 11, 2020, 15:14Would be good for you to come out with me on track to observe my current technique, then come in to the pits to discuss where I can improve. I sat come in to the pits as the car is that loud you can't hear a bloody thing when someone is speaking, lol.
Yeah man, absolutely happy to - I have two lids with intercoms, which work well enough for open cars, so should do the job in yours too.
And yep, your car is definitely not easy to learn in, you're doing well to keep it on the black stuff! You really need to have a crack in mine to see what I mean.
Weirdly though the wheelbase thing seems to be one of those 'internet myths' - it's actually 100mm longer than a 997 911 for example, giving a wheelbase:track width ratio on the MR2 of 1.64, and the Porsche 1.55 - so technically the Porker is less stable.
For further comparison, the latest mx-engineinwrongplace is 1.54, and the original 1.59, an S1 Elise is also 1.59, and the 'golden ratio' is said to be 1.6:1.
So technically, the MR2 is a very 'stable' car!
Really good read and although we've discussed this many times, being able to read and digest at my own pace is really helpful.
Best thing I ever did for my technical skills as a driver was sell the Westfield and buy an MX 5, slowing everything down has brought my driving on in leaps and bounds. I'm nowhere near your skill level (yet 😊) but am so much more confident to jump in any car and thrash it hard having given myself the time to work these things out in a slower car.
I'm actually coming back from what you're describing (in terms of late braking, rather than car rotation), I was always very proud to be the last of the late brakers, gaining maximum 'on throttle' time and minimising the braking zone. However, with a decent data logger during testing and my race at Mallory, found that I could actually be a whole lot faster by braking earlier, lighter and carrying more speed through the corners, letting the brakes lift and turn the rear of the car into the corner and then planting the throttle earlier to 'correct' the car and pull it through. This was wrong wheel drive of course, and I found it almost too easy to drive compared to RWD. It was a massive 'eureka' moment for me though, and I can't wait to try again!
Nearly added that to my post actually... the best way to get better at driving? Buy an MX5 ;D
Quote from: AdamR28 on December 12, 2020, 21:09Nearly added that to my post actually... the best way to get better at driving? Buy an mx-engineinwrongplace ;D
Ok, no MX, but we have 4 rwd cars in the family. No FWD in the last 15.
What do you calla car with the windscreen removed like this? I wonder what other cars could benefit from this sort of help? Boxster? Has anybody done that?
Quote from: Jondoeclsm on December 14, 2020, 18:46What do you calla car with the windscreen removed like this? I wonder what other cars could benefit from this sort of help? Boxster? Has anybody done that?
Speedster.
Yes, many a LeMans racer and before that Brooklands specials had mínimal to no windscreens.
It reduces the frontal area and from there it is a trade off between that and ´slipperyness´ for the bestfor the circumstances.
Quote from: Jondoeclsm on December 14, 2020, 18:46What do you calla car with the windscreen removed like this? I wonder what other cars could benefit from this sort of help? Boxster? Has anybody done that?
Munter ;D
All cars are better without a windscreen. Its a fact.
Quote from: AdamR28 on December 14, 2020, 19:21All cars are better without a windscreen. Its a fact.
When living together with the dog yes...
(https://www.healthypawspetinsurance.com/blog/wp-content/uploads/doggles_dog_car.jpg)
Not so sure about a woman.
Remember the thing TopGear did about no windscreen cars? Now replace the clowns by three random wives dropping off the kids at school.
Quote from: Petrus on December 14, 2020, 19:47Quote from: AdamR28 on December 14, 2020, 19:21All cars are better without a windscreen. Its a fact.
When living together with the dog yes...
(https://www.healthypawspetinsurance.com/blog/wp-content/uploads/doggles_dog_car.jpg)
Not so sure about a woman.
Remember the thing TopGear did about no windscreen cars? Now replace the clowns by three random wives dropping off the kids at school.
Great pic
All this talk of wind, reminds me...
On the way back from an event on Sunday in The Bucket, I snapped a couple of interesting photos while filling up with fuel.
thumbnail_20201213_192150.jpg
thumbnail_20201213_192457.jpg
What do these show? Well, my limited understanding is this...
The car had been on a wet motorway for maybe an hour at this point, so the lines of dirt must mean there is stagnation of the air where the dirt has been left. Both sides of the car shows exactly the same patterns.
First photo - the panel gap is creating some sort of turbulence. Whether that is due to air from the 'outside' stalling in the gap and creating some sort of mini 'air dam', or there is high pressure air leaking out of the wheel arch between the quarter panel and bumper I don't know, but either way that dirt means stagnant air = drag.
Same deal just behind the small flare on the wheel arch, it must be causing some sort of separation to have the dirt sat there in that position / shape.
Up front, again a stalling behind the flare of the arch.
So what does this mean for Mr Poo? Well, I need to get him out of the trailer and have a nosey at the dirt patterns, but I don't remember there being anything as obvious as this after Oulton Park.
That would indicate - maybe - that the front deflectors are doing their job, keeping air out of the wheel arches and the 'spin cycle' of the front wheels / tyres, and thus no stalled air immediately behind the arch flare.
At the back, my only guess is that everything has been sufficiently disrupted by the time it gets to the panel gaps between arch and bumper that there is no decent flow there at all. With there being no side windows air will try to 'spill' from an area of high pressure (down the sides of the car) to low pressure (inside the cockpit), the flat floor will change things underneath a lot too.
Can I make further improvements to reduce drag? I think so. I've been heavily researching vortices these last few days, and I think I can use them to 'seal' areas of the car, and direct air to places I want it to go, rather than where it wants to go.
The idea behind using vortices is that you can combine low energy air from the boundary layer with high energy air further from the surfaces of the car, blending them together in a spiral.
Those who follow F1 might be familiar with the term Y250 vortex. This is a vortex the teams deliberately develop to improve airflow over the car, and it starts at 250mm from the centreline of the car. Why 250mm? Because the FIA banned aerodynamic devices on the front wing for the centre 500mm.
DV1OmdCWAAEBb3v.jpg
So this vortex spins its way down the car, dragging other air with it, bouncing off the bargeboards and then being directed low down the sides of the car. This has a few effects - ensuring clean air reaches the rear wing, and also it attempts to use this highly charged vortex air to 'seal' the underfloor of the car.
Remember the side skirts used in F1 of the late 70s and early 80s, which were banned? Well this is the modern F1 designer's way of trying to emulate that.
https://i.imgur.com/8PyG5vg.gifv
(https://f1techblog.files.wordpress.com/2018/09/f1_vortex_tourbillon-y250_21.jpg)
You will also notice the direction in which the vortex is spinning in the (static) image above - clockwise - so if you are looking at the front of the car, down the left hand side, that spin is trying to pull air out from underneath the car (less air = low pressure = more downforce).
Obviously all of this has to be taken into consideration with other aspects of the car, which is why the front wings on these things are so complex!
The front wing effectively has 3 separate functions. Working from the centreline outwards... the first 25% (ish) creates the Y250 vortex, the middle 50% (ish) generates downforce, and the final 25% (ish) creates 'outwash' - moving turbulent air away from the sides of the car. This has the secondary effect of creating lower pressure directly behind it, which helps 'pull' the Y250 vortex outwards towards the edges of the floor.
Photos... This is the approximate path of the Y250 vortex:
(https://thewptformula.files.wordpress.com/2014/04/y250-analysis.jpg)
And this excellent video shows the other airflow off the front wing (skip to 40s if you wish):
How on earth do we create a vortex then? Well, it's shown in that video just above, at 50s, but in short - we force air to move quickly from a region of high pressure, to an area of low pressure, around the edge of some sort of angled feature.
You may have seen these things on the top of a few models of Mitsubishi EVO, looking a bit like fangs:
(https://www.carbon-addiction.com/wp-content/uploads/2017/04/2008-2012-Mitsubishi-Evolution-EVO-X-Non-SSS-Vortex-Generator-CF-10.jpg)
These little fins are vortex generators. They have a slightly different function in that location, and are obviously less aggressive than an F1 front wing, but it's the same idea.
There are tons of studies out there to try and determine the best shape, height, angle, etc which I won't bore you with, but in short - imagine a 'blade' shape, set around 20 degrees from the air flow direction. The air will run into the face that is being presented into the airflow, creating a region of high pressure. On the opposing side, where the air is being blocked, is therefore low pressure.
The high pressure air tries to 'escape' to the area of lowest pressure (imagine blowing up a balloon and letting the neck go - same thing), and thus spills over the top edge of the 'blade', creating a spiral. We have generated a vortex!
(https://ars.els-cdn.com/content/image/1-s2.0-S0360319917310467-fx1.jpg)
On the EVO, this is used to mix low energy air from the boundary layer - about an inch thick layer of stagnant air which is completely stationary at the roof line, and moving slowly up to around an inch from it - with the fast moving, high energy air that is a little further from the car. The spinning action of the vortex drags these two layers together and mixes them.
Air with more energy can then flow down the rear window of the car more closely - reducing drag and lift, and putting more useful air into any rear wing / spoiler that may be down there.
This is the same deal in the image below - the vortex generators ensure the air 'sticks' to the side pod as it flows down towards the back of the car (along the top of the RedBull logo).
(https://images.cdn.circlesix.co/image/1/640/0/uploads/posts/2016/03/146ddae020303429519863abf9071ed2.jpg)
So, what on earth does this have to do with the MunteR2? I figure I can generate some vortices and use them to my advantage in a couple of areas:
1) Down the sides of the car, creating a 'curtain' preventing air spilling into the cockpit. I can use some small features - a bit like canards in shape and appearance - to spin a vortex along the top edge of the door panel, pulling air out of the cockpit and shoving it down and along the sides of the car.
2) At the rear of the car - giving the air more energy as it separates from the rear quarters, rear bumper, and rear lights, thus producing a smaller low pressure region immediately behind the car (reduced drag).
3) Down the sides of the floor, attempting to 'seal' the floor with an air curtain in the same way as the Y250 vortex does on an F1 car. Obviously this will never be quite as effective, as the air I'll have to use will not be as 'clean', or as fast, but if I can 'suck' a bit of air out from under the floor (considering which direction the vortex spins in) and make it go down the sides of the car instead, that will improve the efficiency of the floor.
I could add side skirts but as I mentioned before, I want to keep the car looking as 'standard' as possible and carry out these tricks out of sight. Side skirts also add weight and can be clattered off stuff.
There we have it. More stupid stuff to mess about with. Can't wait!
How much weight was the screen.
How much benefit?
In too gear ages ago was a car with passenger side covered over. A spare sheet of plywood fitting the gap next to you with enormous holes cut out to leave it as a frame. The holes could be filled with estate agents boards corex board. Fixed when upside down by expanding foam which would encroach onto the hole areas and help keep them from flapping around or worse still, selling a house to somebody trying to drive a car.
Cars.
Porsche boxster might be a good one, hence asking about weight.
I have broken a few 944 cabriolets and some of the parts you would sell wouldn't be needed. You can not a car removing the lights (in the case of 944 the pop up ones). Fibreglass panels available as well.
How about removing a screen from a car and leaving the rear screen out? I have a 944 s at the moment with a new screen not fixed in it. I could take the heavy rear lid (almost 30kgs). It just sets off loads of ideas.
This guy has done the passenger cover.. https://youtu.be/R0Z9uP7DIJE
Thanks for the ponderings and explanations Adam. Aero réally is a huge factor. As I wrote several times earlier in several threads; even in cýcling!!! from some 20 km/h....
LOVE it that you are doing your own thing with it.
Here one of the forum favorite with OEM fitted rear wing for rally use thus none too high speed cornering
(https://cdn.motor1.com/images/mgl/2RLjn/s1/alpine-a110-rally.jpg)
Meanwhile faffing with the sway bars and the ongoing project of adding lightness; sent some mails out again about lightweight bonnet/rear lid.
Quote from: Jondoeclsm on December 16, 2020, 19:20How much weight was the screen.
How much benefit?
Can't remember exactly now, but it is earlier in the thread. 20kg maybe?
The benefit for me is the open-ness and improved driving experience. That said, reducing overall height does reduce the 'plane wing' effect that all cars naturally have due to their shape.
You really want me to fit a rear wing don't you Petrus? ;) Haha. I'm afraid that won't be happening on this car.
I spent some time looking at the dirt on the car after Oulton. Found some interesting stuff...
Looks like the little 'shelves' under the headlights are an aero feature that works in conjunction with the front wheel arches. Check out the flow lines here...
thumbnail_20201218_172253.jpg
thumbnail_20201218_172308.jpg
I think my front 'deflectors' are doing more harm than good, causing flow separation down the sides of the car. Lots of randomly flung dirt there, not showing any flow, which means drag.
thumbnail_20201218_172338.jpg
Having a nosey at the data again, Munter vs MunteR2, the M2 seems to pull bigger gaps on the straights where there are uphills. On the flat, not so much. So I think there is considerable drag here, and also from the dirty air at the back of the car.
I also looked at the front and rear wheels. I'd mentioned before that I thought the fronts were doing all the braking effort - well, looking again, it appears the rears got to at least the same temperature (if not higher). So why is all the brake dust up front? I think it was being 'sucked' out of the wheel area by those front deflectors:
(https://www.invetr.com/uploads/2/1/8/2/21829402/3126116_orig.jpg)
It appears that air curtains are a modern way to ensure good flow attachment down the sides of a car, so I will add something like in the video below - albeit a bit more crude - where he reports 5% reduced drag:
There is also some interesting flow over the frunk lid - it appears to be kind of acting a bit like a diffuser, with the air 'expanding' the further towards the bottom of the screen it goes. This makes sense as the features running back from the headlights are effectively 'boxing in' that air, and guiding it outwards.
thumbnail_20201218_172938.jpg
Towards the back, flow is attaching again before the intake ducts behind the doors.
thumbnail_20201218_173327.jpg
And the tape is preventing a 'stall' on the panel gap, which is happening on my daily:
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And there is attachment after the intake duct, too:
thumbnail_20201218_172410.jpg
Right at the back, the area of low pressure still remains as the CFD model - this will be a good place for a vent to help 'suck' air out of the wheel well.
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Bad news though - this means I have to clean the car before its next outing! I may make up some DIY flow viz type stuff as well.
I've also been looking at borrowing a McLaren feature for the floor, which is some curved deflectors immediately inboard of the front wheels, kicking air out sideways. I have a feeling these are designed to push away the 'squirt' from the front tyres, leaving smoother airflow under the rest of the car to the diffuser.
(https://scontent.flba1-1.fna.fbcdn.net/v/t45.5328-0/s552x414/32299333_1775556135841630_6957550473503047680_n.jpg?_nc_cat=111&ccb=2&_nc_sid=c48759&_nc_ohc=cHYvoh_K3-sAX8HYBs1&_nc_ht=scontent.flba1-1.fna&tp=7&oh=098ed1882b3cc087683d317497b26de4&oe=6003CCF9)
Quote from: AdamR28 on December 20, 2020, 14:30Quote from: Jondoeclsm on December 16, 2020, 19:20How much weight was the screen.
How much benefit?
Can't remember exactly now, but it is earlier in the thread. 20kg maybe?
The benefit for me is the open-ness and improved driving experience. That said, reducing overall height does reduce the 'plane wing' effect that all cars naturally have due to their shape.
You really want me to fit a rear wing don't you Petrus? ;) Haha. I'm afraid that won't be happening on this car.
Perhaps a luggage rack just for use to and from the track ;)
Quote from: SV-3 on December 20, 2020, 14:46Perhaps a luggage rack just for use to and from the track ;)
A tray is a tray is a tray. Make it aero shaped, call it a wing, you can still strap luggage to it ;-)
Concerning the windscreen, removal reduces the frontal area so the overall drag. It also scuppers the airfoil shape of the car thus effect thus does away with most of the lift causes by that. Win - win - win, with he last one being added lightness :-)
Quote from: Petrus on December 20, 2020, 16:44Quote from: SV-3 on December 20, 2020, 14:46Perhaps a luggage rack just for use to and from the track ;)
A tray is a tray is a tray. Make it aero shaped, call it a wing, you can still strap luggage to it ;-)
Concerning the windscreen, removal reduces the frontal area so the overall drag. It also scuppers the airfoil shape of the car thus effect thus does away with most of the lift causes by that. Win - win - win, with he last one being added lightness :-)
Always thought a particular Porsche model featured a picnic table at the rear.
Quote from: SV-3 on December 20, 2020, 14:46Quote from: AdamR28 on December 20, 2020, 14:30Quote from: Jondoeclsm on December 16, 2020, 19:20How much weight was the screen.
How much benefit?
Can't remember exactly now, but it is earlier in the thread. 20kg maybe?
The benefit for me is the open-ness and improved driving experience. That said, reducing overall height does reduce the 'plane wing' effect that all cars naturally have due to their shape.
You really want me to fit a rear wing don't you Petrus? ;) Haha. I'm afraid that won't be happening on this car.
Perhaps a luggage rack just for use to and from the track ;)
At least one member on here has a tyre rack on his engine lid for that purpose.
Ok, so the McLaren floor looks like by sweeping the air out to the side, this will leave lower pressure underneath, so down force greater. Also would that less pressure mean any rear underbody components be less draggy?
In a way like breast stroke pushing air out sideways to make an easier path for the centre, like Moses in a hurry.
Quote from: Jondoeclsm on December 21, 2020, 22:09Ok, so the McLaren floor looks like by sweeping the air out to the side, this will leave lower pressure underneath, so down force greater. Also would that less pressure mean any rear underbody components be less draggy?
In a way like breast stroke pushing air out sideways to make an easier path for the centre, like Moses in a hurry.
The Moses underfloor. I like it! I'm going to borrow that one ;D
Regarding the McLaren 'sweepers', I think it is more complicated than we know.
There's going to be vortices spilling off the sweepers, and these will in fact be rotating in the 'wrong' direction, sucking air in under the floor from down the sides of the car, interestingly. However I assume they have tested this and the effect is less than the gain made by keeping the dirty air out, that would otherwise be under the floor if they weren't present. At least a vortex is highly energetic, flowing well over whatever surfaces it hits - compared with turbulent air which isn't, stalling and sticking to said surfaces.
Regarding reduced drag from lower pressure - I'm not sure on this one, but I will take a stab. Remembering that low pressure under the car is usually created by higher speed of air (Bernoulli principle), this means the air has the same amount of energy either way - either faster but with low pressure, or slower with higher pressure. So my best guess is that it makes no difference, and any 'features' under the car against which the air can act are generally bad news for drag.
On a similar note, watching a Kyle.Engineers (YouTube) video about canards the other day was interesting. It stated that they were poor in terms of absolute lift/drag values (which I knew), but going on to explain why made perfect sense.
The top surface of the canard has high pressure acting upon it. The angle of the surface is usually quite high - say 30 degrees. If you split the force down into vectors (and simplify a bit!), there is a vertical downwards force, but also a horizontal force acting backwards on the canard / car = drag.
The same happens on the underside - which is in low pressure. The low pressure amount can be as much as the high pressure above (again simplified). This 'suction' from the low pressure underneath has exactly the same effect as the high pressure on the top side, just reversed - it now 'sucks' the canard downwards (downforce), but also tries to pull it backwards = more drag.
You can apply this to any part of the car - high pressure on the front of something pushes it back, AND the resultant low pressure behind it also sucks it backwards. Double whammy.
Quote from: AdamR28 on December 22, 2020, 10:23The Moses underfloor.
My previous car was a proper 4x4 ragtop. Looked rather agressive ánd had bullet holes.
We dubbed it Moses´s car because in the city people may way for it :-)
Swith on the indicators, count to 5 and simply go. Ok, I díd look first, but that was courtesy ;-)
The MR2 seems to be invisible. The no-muffler is an essential active safety device.
Long time, no update!
Track days now open again, and having shared the original Munter with
@Maurici at Oulton Park this week (thanks mate!) I'm very much looking forward to the 'return leg' at Cadwell Park this coming Thursday.
A few pics from Oulton first...
The Munter in all its glory.
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Forgot a spoon for my lunch, so the lesser spotted 22mm spanner and some tape was employed.
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Wore out some brake pads a bit too much...
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And watched a 458 set on fire.
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Anyway, with Cadwell looming I thought it was about time to start tackling the todo list.
I had a GRP diffuser lined up, but that didn't happen in the end, so set to with some ali sheets to make this monstrosity. Went full Time Attack for shits n giggles.
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Supports courtesy of some brackets removed from an IBC that I'm currently converting into a wood fired hot tub. Fred Dibnah would be proud.
Full pikey mode for the newly adjustable rear ARB.
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And a new deflector for the front duct, hoping it'll make the cockpit a bit less buffety.
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Still a few more bits to do, but the diffuser was the main job after the first outing many months ago.
Some pics for
@Petrus ...
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Yiiiihaaaaa!!!!
Im so excited about crashing this one. Difuser and all. Will be absolutely spectacular!!
See what you did Adam. Thanks! Much appreciated!!
Unfortunately that spot is not working in my case: I need to be able to swap for the OEM bonnet and the inner frame thwarts it. Also not a lot of ´meat´ from the edge for a fiber one.
May best be using the hinges after all. Lange flat head bolts may look not too bad.
Will be using those push buttons you have at back, at the front.
Am working on a tonneau cover. Maybe something for you to close the tub? If we get the first made, the second will be less pita. I´d do it without eyelets/buttons so you could fit it as suits yoú.
Loving it! More videos
I am still trying to work out where the half barrel is going!
Quote from: Topdownman on April 24, 2021, 19:30I am still trying to work out where the half barrel is going!
We drank the content ages ago... is now a surplus.
🤣 jokes aside, I have also spotted it, and wondering where it goes...
As I know you love mx5... im going to leave this here to be hated.
I expect a similar one in cadwell but with MrPoo.
Ladies and gentleman... MrPoo's inspiration, the original Munter. (Im now the lucky person fostering Adam's original pride and joy)...
Cadwell is a bit less power dependant as you rarely have your steering wheel straight, I expect the MR2 will keep up much better with heavy machinery.
@AdamR28 r you building the spare shell already?
Love this thread. 8) >:D
(Sorry, I'm very late to this one)
Quote from: TopdownmanI am still trying to work out where the half barrel is going!
Passenger seat ;D
Managed to get a few more bits done on the car before Cadwell, namely an extra deflector for the front duct, tweaked rear ARB setup, and a set of louvred arch vents, aka The Cheesegraters.
u1.jpg
u5.jpg
Awful, eh? Still, they are a talking point, and they won't harm.
u2.jpg
Tried to remove the rear ARB, bolt snapped, didn't have time to fix it properly.
u6.jpg
So had to do the welding in situ. Worked ok. The clamp slides up and down for adjustment, only one 13mm spanner required.
u7.jpg
Ready to rock! Bits of red tape because I kept walking into the Max Power Time Attack ALLLLthedownforce rear diffuser. I take the piddle but it does actually work, which is nice.
Anyway, yesterday (Cadwell) came round rather quickly, but once we'd left the house felt pretty chilled. There was a bunch of half a dozen of us who camped over the night before, had a BBQ, chatted some crap about cars and other things.
@Maurici came along for 'Leg 2' of our car-swapping session, and apparently managed an amazing night's sleep in the back of his car. Legend.
The day started veerrryyy chilly, with talk of shivering in tents and extra hats, and even a bit of frost very early on, but was mostly dry apart from a couple of hail showers which just so happened to coincide with my sessions... ;)
The car went really well - the balance is better than last time, but it is still a bit too lairy. My thoughts now are that there is too much roll in the car, allowing the rear to toe out (a lot) under hard cornering and transition to throttle on the exit (squat). I have a set of Whiteline ARBs I'll play around with before next time. The front deflectors ground out a LOT (which sounds horrible - you can hear it on the videos) and the front splitter got a bit scuffed, so I'll raise it 10mm or so. Other than that, not much to do.
Buffeting in the cockpit is better (bearable now), brake pads hardly worn at all, tyres barely worn and they are actually pretty good (datalogger shows over 1.5g lateral through Coppice!), stuff didn't fall off (although Maurici gave it a good go, managing to bump a tyre wall mid spin - and somehow not damage the car at all, I'll let him explain that one!), and oil consumption has even reduced a bit. Slightly disappointed at that, given the previous oil burning rate would have seen a full oil change every 4 track days, which would have been perfect self-maintenance - never mind.
Minimal damage from 'the off'!
u3.jpg
I have a few more posh things to add to the 'Kill List', including a Cayman GT4, latest Focus RS, an M140i, and it appears the little Snotrag was also lapping faster than some 200bhp+ kit cars that were there. Bonus.
Must be the eXtreme MotorsPOO stickers and mirrored 'FULL SEND' that Maurici made up and stuck on. Thanks mate ;D
u4.jpg
Just realised I forgot to mention the side air curtain generator things and a hugely cut out front wing. There they are. I say win
g, because I didn't have time / couldn't be arsed to do the other one. So it'll probably stay like that forever now.
u8.jpg
Video from my perspective...
And Maurici has one which I'll let him post up if he likes.
Cheers for reading!
Yep. I did manage to crash (pretty heavily from the inside) in barns... did about a 360 and managed to hit the tyre wall while spinning in the grass... wall deflected a lot and I was expecting the same result in the car. I still cant beleave i didnt damage anything. Took the car out of track on my own... I was medically checked and all. Despite i got a new wristbant and i was cleared for driving again, I called it a day. Again... sorry
@AdamR28, it could have been much worst. It now feels wrong that I joked about it in my last post.
Pretty ashamed about the whole thing... specially because for what Adam told me, watching from the outside they were expectind the crash in hall bends for several laps.
I was driving waaaaaaay to hot and the car is still a bit of a handfull. Mostly controlable... till you flogg it in to the barriers. Pretty fun tho.
This is my morning session. Sadly the crash was not recorded...
Quote from: Maurici on April 30, 2021, 17:05It now feels wrong that I joked about it in my last post.
Makes it even funnier if you ask me! Really not a problem mate, no need to apologise - only thing that matters is that you aren't hurt and will still continue to drive like a lunatic again in future ;)
That looks like such amazing fun. Good driving!
Love the thread. It's properly different but brilliant
@AdamR28 is Maurici needing to be smoother going in to corners? I can understand you using opp-lock in the wet, but is it needed in the dry?
Quote from: Gaz mr-s on April 30, 2021, 22:18@AdamR28 is Maurici needing to be smoother going in to corners? I can understand you using opp-lock in the wet, but is it needed in the dry?
Looks like it was intentional. For fun :)
I'd be doing the same for laughs and practice.
Quote from: Gaz mr-s on April 30, 2021, 22:18@AdamR28 is Maurici needing to be smoother going in to corners? I can understand you using opp-lock in the wet, but is it needed in the dry?
The car's back end is extremely loose.
Even without wanting it, the rear rotates A LOT... and the line between rotating it with throttle and having the back end completely off was waaaaaay to fine
Shall i be smoother? Probably... but I maybe also need more talent to keep the car rotating without having to go completely sideways...
Or just stop driving that bloddy thing before it kills me🤣🤣🤣
I love this build. Home built, light, quick, cheap, totally original, stone great engineering, doesn't look like much but pisses off big bucks cars... Perfect!
Quote from: Maurici on April 30, 2021, 23:10Even without wanting it, the rear rotates A LOT...
That comes with a low MR2 ;-)
As you mentioned already, playing tith the ARBs can help. Going front relatively stiffer would balance the car towards more rear grip.
Mind you, it will still rótate just as quicky, that is the low moment of inertia, but the rear might let go less binary.
Also tyres. Find a set that has a broader top.
Lastly the driving.
The tyre adhesion graph has TWÓ points with the same grip; one before the top, one over. The latter is at a larger angle of slip so scrubbing off more speed ánd it is at the downward slope meaning more slit anle = léss grip = going quicker.
Driving at the one on befóre the top is exactly the same max corner speed, less power needed to maintain it and it has more margin of control.
Works like that on motorcycles too :-(
(https://external-content.duckduckgo.com/iu/?u=http%3A%2F%2Fcfile2.uf.tistory.com%2Fimage%2F230C0E3A550DE6A334F060&f=1&nofb=1)
Cheers
@Petrus .
The MunteR2 has pretty much standart ride height... according to Adam, the toe out transition in roll (bump) with the current geometry is what screws the back end.
The current plan aparently is stiffen quite a lot the rear ARB keeping the suspension as it is so it will limit the roll and make the back end more predictable.
Obviously front will have to be stiffened equaly to balance the front/rear grip. Adam will explain it way better than me.
We are familiar with tyre behaviour too. Will see how many times I crash it till it behaves how we like :).
Eres de Malaga? No es muy comùn encontrar españoles en foros ingleses!
Quote from: Maurici on May 1, 2021, 10:54Cheers @Petrus .
The MunteR2 has pretty much standart ride height... according to Adam, the toe out transition in roll (bump) with the current geometry is what screws the back end.
The current plan aparently is stiffen quite a lot the rear ARB keeping the suspension as it is so it will limit the roll and make the back end more predictable.
Obviously front will have to be stiffened equaly to balance the front/rear grip. Adam will explain it way better than me.
We are familiar with tyre behaviour too. Will see how many times I crash it till it behaves how we like :).
Eres de Malaga? No es muy comùn encontrar españoles en foros ingleses!
Thanks Maurici.
I think that it the wrong way round. It will redúce grip at the rear.
The simplest is to cut down the spring a bit to set the ride hight a bit lower. That will address the geometric issue.
Than stiffen the front ARB móre than the rear. That will give relatively more grip at the rear.
The ARBs are so simple to play with. Just try.
Pues si soy residente en la provincia de Málag desde 20 años pero nació en los Paises Bajos. Dus Nederlands gaat ook perfect ;-)
Quote from: Petrus on May 1, 2021, 14:08Quote from: Maurici on May 1, 2021, 10:54Cheers @Petrus .
The MunteR2 has pretty much standart ride height... according to Adam, the toe out transition in roll (bump) with the current geometry is what screws the back end.
The current plan aparently is stiffen quite a lot the rear ARB keeping the suspension as it is so it will limit the roll and make the back end more predictable.
Obviously front will have to be stiffened equaly to balance the front/rear grip. Adam will explain it way better than me.
We are familiar with tyre behaviour too. Will see how many times I crash it till it behaves how we like :).
Eres de Malaga? No es muy comùn encontrar españoles en foros ingleses!
Thanks Maurici.
I think that it the wrong way round. It will redúce grip at the rear.
The simplest is to cut down the spring a bit to set the ride hight a bit lower. That will address the geometric issue.
Than stiffen the front ARB móre than the rear. That will give relatively more grip at the rear.
The ARBs are so simple to play with. Just try.
Pues si soy residente en la provincia de Málag desde 20 años pero nació en los Paises Bajos. Dus Nederlands gaat ook perfect ;-)
Well. Will leave the geo setup and discussion to Adam, who happens to know a bit more than me on the topic :P
Im from Mallorca, but life got in the way and ended in Cheshire, uk... hope you enjoy spanish weather a bit for me...
Had a good long read of this thread today. Great work, love the out of the box thinking and great ideas of building what and how you want it to be.
Quote from: Maurici on May 1, 2021, 14:15... hope you enjoy spanish weather a bit for me...
I will, I will, it´s a rotten job but sómeone will have to do it :-)
Staying with Bubbly; Antequera gf, and for sure enjoying doúble ;-)
This evening open air concert en ´el Cortijo´.
Tomorrow in the mountains with Mountain Girl; Vva del Trabuco.
Lunes, a por Torremolinos.
Ademá un dia de semana que entra a Motril. Iré por carreteras comarcales de Granada con el MR2.
Watched this round Caldwell on YouTube last night, looked to go really well!
Thanks for the input and comments guys - glad this thread is offering at least a little entertainment!
I'm going to brain-splurge a bit now, but hopefully some of it may make sense and even assist another member in future.
So, the main issues with the car at the moment... these can be driven around but that's not really my style, I like to feel completely in-tune with the car so I can take my brain out and just enjoy.
1) It bottoms out all over the place. Solution: Raise the front splitter a bit. Simples.
2) It oversteers like buggery. Solution: A bit more long-winded.
So we know the rear of the MR2 toes out in bump. This is a desireable characteristic for a low powered sports car, allowing the rear to roll through the corner without scrubbing speed off. Porsche spend millions developing these sorts of 'active rear steering' systems for their cars, we have a budget version already built in.
It seems that one of the main reasons for toe out in bump is actually to produce the opposite effect, toe in under rebound - what this does is help to tuck the rear back in if a less experienced driver gets into oversteer and lifts off the throttle. The lift shifts weight to the front end, making the rear suspension extend, and the outside rear wheel goes towards toe in, keeping things in line.
However, when you have an experienced driver who keeps his or her foot in during oversteer, this makes the car bite / squat more at the rear, compressing the suspension further, and giving more toe out, which means more oversteer!
This reared its head at Cadwell many times, and was more prevalent with a passenger in - more compression on the suspension due to more weight in the car = more toe out.
Compare the oversteer here at 1:59:
To that here 4:36:
Perhaps on a more 'normal' track version of this car the whole rear toe thing isn't too much of an issue, but with very soft suspension and aero (which actually works - the car pulls 1.5g through Coppice and 1.3g on other flat high speed corners - it should only be doing about 1.0 - 1.1g on these tyres!), the wheels are moving up and down a lot, and the suspension is under considerable load. Note comparison to other cars: https://fastestlaps.com/lists/top-grip-kings
Now, the standard rear bushings are pretty floppy, for compliance on the road. Under the sorts of loads I'm subjecting Mr Poo to, the rear end is going to be flexing all over the place. I think I need to add some more static toe to get the rear end to not go into wild toe out under load. I could spend ages and loads of money adding fancy bushings / rose joints etc, but I can't be arsed. That isn't what this car is about. So a bit more rear toe in it is.
There is also a lot of chat online about adding loads of roll stiffness (springs and / or ARBs) to the front of these cars for track use - which would have the effect of adding understeer / reducing oversteer - but I'm not sure. I like the car to rotate when I tell it to, and I hate understeer. The car is for fun, not racing, so while it may be faster with some more 'push', that isn't the aim.
The car also doesn't have excessive body roll, and body roll is what tells the driver what's going on with the car (more body roll = more feedback). So I am a little loathed to stiffen the car. See below.
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(Photo copyright MSV, I have since purchased this photo)
The rear toe change is also very easy to do - so that's my next step. Completely at odds with what 'the internet' says I should do, but hey, isn't the whole car?
A couple of questions in the posts above...
Opposite lock in the wet or dry is no different. The car gets a slide on to x angle, it needs y amount of steering lock to keep the car pointing forwards. You just (usually) see it more often in the wet because the driver has more time to react to a slide (lower grip levels means the car transitions the point of adhesion with less violence), thus they let the car get closer to the limits more often. In the dry, the car can get away from you very quickly (especially with stiff suspension and sticky tyres), so most drivers don't go there for fear of binning the car. The 2nd video in this post at 4:36 (and also a few times at 1:02) shows a lot of opposite lock, applied and removed very quickly - in the wet this would take place over a much longer period of time, so it is also more noticeable. But let me tell you, in the car this is pretty scary!
Maurici is pretty aggressive with the car. That's his style. He prefers a car that has more understeer because of this - it means there is a wider window before it gets out of hand. This in itself is a testament to his skill and car control, 1) that he has generated a preference and 2) he can still catch a car that oversteers a lot!
The ride height of the car I mentioned earlier in the thread and will go and have a look after this post, but from memory it is technically around 10mm lower than standard. The car just looks stupidly low because of the splitter and tiny wheels / tyres (2" smaller diameter than standard). I knew lowering it a lot would significantly upset the geometry, so didn't want to do this.
Not sure when the next outing will be, so this thread may lie dowmant for a while now...
Quote from: AdamR28 on November 22, 2020, 18:11Total: 306lbs / 140kg of downforce! That would be enough to lower the car about 15mm at speed, which would be, er, interesting.
Just spotted this...
It looks from photos that the car does drop ride height noticeably at high speeds.
Estimating 1.0 - 1.1g (say 1.05) of lateral g without downforce in an 830kg car (inc driver and fuel), but it actually pulling 1.3g consistently, means the car 'weighs' (generates vertical load) of more like 1020kg at high speeds. I can't say that is 190kg downforce, but there seems to be around 190kg difference between the amount of lift the standard car produces, and any amount of negative lift (downforce) Mr Poo has. Significant!
Quote from: AdamR28 on May 6, 2021, 08:15Maurici is pretty aggressive with the car. That's his style. He prefers a car that has more understeer because of this - it means there is a wider window before it gets out of hand. This in itself is a testament to his skill and car control, 1) that he has generated a preference and 2) he can still catch a car that oversteers a lot!
I'm now over the moon... taking in account I had a shag with the tyre wall...
Thanks! :)
Q&D:
Stiffen the front ARB a bit.
Stiffen rear springs a bit.
Bolt on a Silly Big Wing on the back.
The latter adds traction at the rear only, not changing the frequency of the rear suspension (apart from slówing it down a whiff because of extra load), can be done in half an hour for 100 Euros while you think about the rest.
Don´t like it; it´s off in 15 minutes and resold or re-used in a different project easily.
Oh and mine now is under 3 kg. in all.
Quote from: Petrus on May 6, 2021, 10:52Stiffen the front ARB a bit.
Stiffen rear springs a bit.
Bolt on a Silly Big Wing on the back.
Thanks for your input as always!
However, these three things will also achieve the following:
- Make the car stiffer (already said I don't want to do that).
- Add weight (don't want to do that)
- Add drag (don't want to do that)
- Add cost (don't want to do that)
- Take a lot more time to do than the solution I came up with (don't want to do that)
Will be interesting to see how the changes go :), ive played around with the Whiteline bars on mine and found with rear one even on full soft it was too much for me on a sprint event with cold tyres, it just kept trying to swap ends mid bend as car loaded up outside wheel coming onto power no matter how smooth i was, disconnected it and next run was fine so i refitted stock rear bar which seems to work for me and sold rear whiteline.
I probably should of kept the rear whiteline for trackdays as it felt ok on the one i did with it, no doubt the warmed up tyres helped and it certainly helped reduce body roll a touch as well, im like you i prefer car of softer side but some reduction in roll is good and why ive kept the front whiteline which is on stiffest setting, car doesnt understeer for my style at all and is very balanced even on cheap hankook road tyre i ran at croft on monday in wet.
Had a EP3 Civic owner lad drive it as well and he was expecting understeer with snap oversteer but was amazed how well it turns in and just grips and its so hard to unstick the rear! to be fair it was on the Zestinos semis at time but he was passenger for many laps when Hankooks went on and rain came down and was still impressed, as was i for budget tyres!
Keep up the good work :D
Really good info that, thanks Ian! I have a set of Whiteline ARBs knocking about as an option if I want down the line.
Still have some wheels for you! Might be up in the Lakes next weekend (15th) if any good to you?
;D ;D ;D ;D ;D ;D
Enjoy!!
I have the marine quality pleather for the tonneau in and am out sourcing the fittings.
Quote from: AdamR28 on May 6, 2021, 11:43Really good info that, thanks Ian! I have a set of Whiteline ARBs knocking about as an option if I want down the line.
Still have some wheels for you! Might be up in the Lakes next weekend (15th) if any good to you?
If you decide not to use the rear whiteline i might be interested to have it for trackdays just let me know :)
Hmm what were the wheels? sorry ive totally forgotten! :-[ :-\ :o
Cadwell looked a lot of fun mate. A track i'm desperate to do.
Interesting points on dynamic rear toe too, if you don't want to stiffen it up then looks like you'll have to find a nice static toe in balance? I current run 3mm total toe in on the rear, but as its quite stiff it wont affect dynamic toe nowhere near as much as yours. Mine is set-up quite safe with 3mm, but I like the balance, it suits my intermediate skill level.
Would love a go of the MunteR2 versus mine, polar opposite MR2's but in your hands would pump out very similar lap times I'd bet. Managed to weigh mine last time out at Oulton....950kg bang on so running just shy of 200hp p/ton.
Crazy how you can pull similar G's to me running wide rear AR1's, just shows how functional your aero is. Aero is next on my list of mods.
I'm back at 3S on Monday, first time since the evening session we attended. Hopefully it goes better for me this time, lol.
Keep up the good work.
All interesting stuff. Glad you're sticking with your mantra of keeping it supple. I like a bit of roll to feel what the car is doing.
A bit off topic but do you still recommend the Apec brake pads
@AdamR28?
May not relevant but I've seen it written that some of the race guys don't use a rear a/roll bar at all.
Quote from: Gaz mr-s on May 6, 2021, 21:10May not relevant but I've seen it written that some of the race guys don't use a rear a/roll bar at all.
It is mostly about whether the driver needs or prefers understeer or oversteer.
For a given set up, the less rear sway bar the more grip at the rear and relatively less at the front.
Personally I get nervous by understeer. Again a heritage of motorcycle racing probably.
There is a bit of an adder under the gras. By changing the sway bar either fron or rear the roll frequency of the car is changed.
As a rule of thumb the rear needs to be a bit quicker that the fron, just like the suspension frequency.
The reason being that the front not only gets into the corner firts, it also it stééred. To get a balanced response, the rear needs to be a bit quicker.
It is therefor interesting that TRD doúbled the rear spring rate for both the Sportivo and Racing springs whereas the stock is 50% stiffer; it ups the rear frequency.
By softening/removing the rear sway bar the roll frequency is lówered at that end; it will set in the corner later.
More grip but lagging a bit. It will be most noticeable in chicanes. Will also have more ´swing back´ when correcting oversteer.
It illustrates thé tricky thing with suspension; everything affects everything else. There is no such thing as júst more/less grip at either end.
Quote from: thetyrant on May 6, 2021, 12:35If you decide not to use the rear whiteline i might be interested to have it for trackdays just let me know :)
Hmm what were the wheels? sorry ive totally forgotten! :-[ :-\ :o
Okey doke, will do, cheers!
Pair of FL 16" rears, FOC if you still want em mate.
Quote from: JB21 on May 6, 2021, 15:10Keep up the good work.
Thanks Phil, and thanks for the toe info! I am pretty sure I have less than 3mm at the moment, we'll see in a couple of weeks when I check it out.
Quote from: Roj on May 6, 2021, 20:31A bit off topic but do you still recommend the Apec brake pads @AdamR28?
Yep, still using them - and still no visible wear! Not really that surprising, as the car is much lighter than say an MX5, and has much bigger brakes.
Got an interesting day set up at Blyton Park mid June - a mate of a mate has a couple of supercars and has hired the track for the day. We've been invited along to share the day, so Mr Poo will be in some slightly less tatty company!
Quote from: AdamR28 on May 12, 2021, 06:28Pair of FL 16" rears, FOC if you still want em mate.
Ah yes had forgotten all about those!, i picked up a set of mx-5 15's for track use last week so dont really need those 16's now but sure someone will have them off you :D
Quote from: AdamR28 on May 12, 2021, 06:28Quote from: Roj on May 6, 2021, 20:31A bit off topic but do you still recommend the Apec brake pads @AdamR28?
Yep, still using them - and still no visible wear! Not really that surprising, as the car is much lighter than say an MX5, and has much bigger brakes.
Great stuff, cheers. I have an afternoon at Knockhill in a few weeks, so I'll give them a try.
Quote from: Roj on May 12, 2021, 07:57Great stuff, cheers. I have an afternoon at Knockhill in a few weeks, so I'll give them a try.
How did you get on Roj?
So, a bit of Blyton prep today. All went very smoothly which was nice!
First up, rear toe setting. It was at 10 minutes in, and my theory of it crossing to significant toe out under hard cornering seems to have been correct.
Car at full 'lift', with the rear wheel just about to come off the floor (gauge is reading 'backwards' here):
20210608_144557.jpg
Car at ride height...
20210608_144715.jpg
And with 100kg balanced on the rear corner.
20210608_144932.jpg
Quite a significant toe change!
Now set to 40 mins in across the axle, see how that goes.
Had a nosey at tyres and brake pads.
Pads all good.
20210608_152938.jpg
20210608_153022.jpg
Tyres, more wear rear than front, and more on the left than the right - as you'd expect. They've done well for two sideways track days though, should get 5 days out of them in total I reckon. Nice even wear shows the camber settings are about right too.
Front right.
20210608_152923.jpg
Rear right.
20210608_152928.jpg
Front left
20210608_153407.jpg
Rear left
20210608_153416.jpg
Swapped them front to rear, and given next outing is Blyton (anti clockwise) that should even the left-right wear out nicely.
And finally a small shifter hack. Both
@Maurici and myself missed 2nd a few times at Cadwell, due to the 6 speed box having reverse up to the side of 1st. You get a bit excited and push a bit hard sideways, so the shift doesn't go in at all and you're left fumbling mid corner without any engine braking!
Step in a random offcut of ali, a bolt, a nut, and a few washers.
Stops in just the right place to slip nicely into 2nd (or 1st).
20210608_163940.jpg
Need reverse? Just swing it out the way, then back again afterwards!
20210608_163958.jpg
Quote from: AdamR28 on June 8, 2021, 22:23And finally a small shifter hack. Both @Maurici and myself missed 2nd a few times at Cadwell, due to the 6 speed box having reverse up to the side of 1st. You get a bit excited and push a bit hard sideways, so the shift doesn't go in at all and you're left fumbling mid corner without any engine braking!
Step in a random offcut of ali, a bolt, a nut, and a few washers.
Stops in just the right place to slip nicely into 2nd (or 1st).
20210608_163940.jpg
Need reverse? Just swing it out the way, then back again afterwards!
20210608_163958.jpg
Get a 5 speed even the UK ones shift better. A JDM is better still with better ratios.
Yeah, prefer the 5 speed in my daily. But can I be arsed to swap it? Nooooope!
Quote from: 1979scotte on June 8, 2021, 22:32Quote from: AdamR28 on June 8, 2021, 22:23And finally a small shifter hack. Both @Maurici and myself missed 2nd a few times at Cadwell, due to the 6 speed box having reverse up to the side of 1st. You get a bit excited and push a bit hard sideways, so the shift doesn't go in at all and you're left fumbling mid corner without any engine braking!
Step in a random offcut of ali, a bolt, a nut, and a few washers.
Stops in just the right place to slip nicely into 2nd (or 1st).
20210608_163940.jpg
Need reverse? Just swing it out the way, then back again afterwards!
20210608_163958.jpg
Get a 5 speed even the UK ones shift better. A JDM is better still with better ratios.
Surely this thing is crying out for a 2ZZ gearbox swap!
Cheap and weight penalty free way of improving acceleration.
Quote from: AdamR28 on June 8, 2021, 22:13Quote from: Roj on May 12, 2021, 07:57Great stuff, cheers. I have an afternoon at Knockhill in a few weeks, so I'll give them a try.
How did you get on Roj?
I didn't get my 2.1 gearbox back in time so I ended up taking my Golf on track. The standard brakes on that didn't hold up well at all, horrendous pad transfer when hot.
Quote from: Alex Knight on June 9, 2021, 07:04Surely this thing is crying out for a 2ZZ gearbox swap!
Cheap and weight penalty free way of improving acceleration.
That sounds interesting. Thanks for the heads up!
Blyton Park yesterday was quite fun!
How often do you see a Huracan?
How often do you see a Huracan on track?
How often do you see a Huracan exiting a track backwards and entering a field?
How often do you see that twice in two laps? ;D
The owner was clearly a very confident driver, giving it full beans all day, but after coming out for a few drifty laps in Mr Poo decided to turn all the electronics off and have a go at some drifting.
It was probably the funniest thing I've seen for ages. The guy was loving it, didn't seem to be worried at all about the car, just treating it like the pile of metal, plastic and rubber that it is.
I'm glad I persuaded him only to try it at Bishops, Bunga Bunga and the final corner though!
Other cars in attendance were along the lines of... Two R8s, one V8, one V10, C63 AMG, new Panamera hybrid, 911 Turbo, Cayman GT4, Giulia quatraformagia (or whatever its called - the 510bhp one anyway), Yaris GR (also sideways a lot and in the field a couple of times), Elise, VX220, E92 M3, a 200SX that could not keep in a straight line (it was wet all day) and various others I have forgotten. So Mr Poo was obviously the shittest thing there.
My mate Danny, who was due to share my car, absolutely loves supercars / fancy cars so he only ended up doing 3 laps of driving all day - instead shepherding / persuading as many people as he could to jump in for some pax laps with me, and chatting everyone else up so he could jump in with them!
The Huracan and V10 R8 sounded glorious, and despite the wet track kept lapping with gusto, with everyone else getting plenty of track time given the low numbers and chilled vibe.
20210618_152825.jpg
With all the excitement I barely got any photos and completely forgot to stick the camera in the car, but I can confirm that adding more rear toe in has helped. The car will still get wildly out of shape (and catch it well) if you want, but it does actually understeer a bit at times now.
I'm unsure if it was wind direction or aero balance related, but coming out of Port Froid the car wanted to oversteer every lap - perhaps a balance shift towards a bit more understeer is required for next time.
Even in the wet the rear brakes lock first, so that bias valve I've had knocking around for ages needs to go in ideally. May explain why the car will pull 1.3g in the bends but I struggled to get over 0.9g on the brakes last time out!
Oil consumption is about the same, perhaps a little better again, though the tensioner seal is very leaky now and I have feeling that is letting as much through as the piston rings :))
The shift stopper works perfectly, love how a simple mod cam transform a car!
So all in all a very successful and enjoyable day, with a few tweaks to make for next time if desired.
Sounds belting Adam, love a Blyton track day. Especially one littered with exotics. How did you find the new orange look Blyton? Have they lowered any kerbs? Is it any faster?
The exit of Bishops is sooooo wide, it takes a bit of getting used to. Its about 1s faster over a lap because of this.
The rest of it is the same bar paint, except psychologically the points where the new tyre stacks are make you give them a bit more of a wide berth, if you see what I mean!
Quote from: AdamR28 on June 19, 2021, 14:44Quote from: Alex Knight on June 9, 2021, 07:04Surely this thing is crying out for a 2ZZ gearbox swap!
Cheap and weight penalty free way of improving acceleration.
That sounds interesting. Thanks for the heads up!
I'm mid way through a 2.1ZZ 'box swap. C66 1ZZ 6spd with LSD, with first to fifth and the final drive from a C64 2ZZ' box swapped in, keeping 6th and the slipper from the original 'box. New clutch and lightweight flywheel are in but I've been struggling to get the box lined up using a trolley jack and engine support beam, so I can't report back on the results yet!
I posted a comparison of the ratios in this thread: https://www.mr2roc.org/forum/index.php?topic=70628.msg845311#msg845311
Car went well yesterday mate! looked good fun on track , I got so caught up I couldn't get over to say hi. So many people were asking for passenger laps, and chatting etc
Franks days are such a good laugh.
I reakon it would be great if you stuck a 2zz gearset in there, with the weigh you are down to, I should think you'll be on par with the 2zz in the straights, if not a bit quicker.
But man that car is desperately calling out for some track tyres after following. Looks like fun going side ways, but in comparison, when its clear in front I can happily be flat from the first corner of bunga bunga to the corner before pit exit.
With some track tyres on it, it would be a weapon!
I do like the new exit of bishops! its such a great corner now. TBF its a fun track and really suits the MR2 well
I'm three sisters next, then off to Anglesey
On a side note reading above about oil consumption, there was no blue smoke out the back ;D
Quote from: pistol pete on July 2, 2021, 08:20Car went well yesterday mate! looked good fun on track , I got so caught up I couldn't get over to say hi. So many people were asking for passenger laps, and chatting etc
Franks days are such a good laugh.
I reakon it would be great if you stuck a 2zz gearset in there, with the weigh you are down to, I should think you'll be on par with the 2zz in the straights, if not a bit quicker.
But man that car is desperately calling out for some track tyres after following. Looks like fun going side ways, but in comparison, when its clear in front I can happily be flat from the first corner of bunga bunga to the corner before pit exit.
With some track tyres on it, it would be a weapon!
I do like the new exit of bishops! its such a great corner now. TBF its a fun track and really suits the MR2 well
I'm three sisters next, then off to Anglesey
On a side note reading above about oil consumption, there was no blue smoke out the back ;D
By the end of the day we managed to make it flat... ish too.
It was sort of scary, but to be fair, the quicker we were going through the last corner on port foid the better the car was handling. I think Adam managed to go flat a few times, I learnt to do it without a full lift...
@AdamR28 did some further changes yesterday on track and finally the thing is driveable. Prior to the changes I span in my second lap... again!
Quote from: Maurici on July 2, 2021, 08:31By the end of the day we managed to make it flat... ish too.
It was sort of scary, but to be fair, the quicker we were going through the last corner on port foid the better the car was handling. I think Adam managed to go flat a few times, I learnt to do it without a full lift...
@AdamR28 did some further changes yesterday on track and finally the thing is driveable. Prior to the changes I span in my second lap... again!
Brilliant.
I know what you mean by flat ish. a very small lift on the left-hander But there is a huge difference between flatish and flat when you get to the last corner, all morning on the r888r's i had to do a very small lift (flat ish) then i swapped to the A052s. and could go flat, the speed difference is quite a lot :)
I don't know your budget or build direction you plan on, but tyres would completely transform the car, even just a set of AR1's
Not sure who was infront of me out of you two, but I did stay back quite a bit coming to corners, as it was "entertaining" to watch on the corners shall we say, its a fabulous concept. Can't wait to see what you do with it moving forward.
I want to do the same with my doors as you have done (single skin) but I need to get some plastic windows first.
I had a quick look first thing but no one was around the car at the time to chat to
What changes did you manage to do on track. Everybody likes a slightly different setup on a MR2, I tried the rogue alignment, and wasn't for me. I have mine own and its so stable
Quote from: pistol pete on July 2, 2021, 10:22Quote from: Maurici on July 2, 2021, 08:31By the end of the day we managed to make it flat... ish too.
It was sort of scary, but to be fair, the quicker we were going through the last corner on port foid the better the car was handling. I think Adam managed to go flat a few times, I learnt to do it without a full lift...
@AdamR28 did some further changes yesterday on track and finally the thing is driveable. Prior to the changes I span in my second lap... again!
Brilliant.
I know what you mean by flat ish. a very small lift on the left-hander But there is a huge difference between flatish and flat when you get to the last corner, all morning on the r888r's i had to do a very small lift (flat ish) then i swapped to the A052s. and could go flat, the speed difference is quite a lot :)
I don't know your budget or build direction you plan on, but tyres would completely transform the car, even just a set of AR1's
Not sure who was infront of me out of you two, but I did stay back quite a bit coming to corners, as it was "entertaining" to watch on the corners shall we say, its a fabulous concept. Can't wait to see what you do with it moving forward.
I want to do the same with my doors as you have done (single skin) but I need to get some plastic windows first.
I had a quick look first thing but no one was around the car at the time to chat to
What changes did you manage to do on track. Everybody likes a slightly different setup on a MR2, I tried the rogue alignment, and wasn't for me. I have mine own and its so stable
Ah. You were there with the posh mr2 silver, green, massive gay wing... :P
Pretty sure it was Me in front of you. Dont tell me you was holding back, i was sooooo excited you could not keep up.
You have just ruined my day. Bollocks.
We stiffened the rear ARB to avoid body roll and again toe out in bump... a bit counter-intuive, and i wasnt sure about it but adam was convinced it would work. And it did.
I know what you mean with the difference of flat and flat-ish... I have driven blyton with several CRAZY power cars and posh tyres and yes there is a difference at the end. But... is only a super cheap trackday tool, and with the eco tyres is so fun. What is the point to make it faster? We have other toys for that.
Not sure of the future direction... Adam is the project manager there, but ill be very suprises if i ever see any posh rubber in that car.
Project manager. Ha!
I'll write more later, but for now - shame we didn't get to chat Pete, I also tried a couple of times but you were speaking with someone else or not there. Never mind!
Couple of vids:
And later in the session when Port Froid was flat. Not comfortable, but a lot of fun on the ditchfinders!
Have some data to look over too, which should be interesting.
Quote from: AdamR28 on July 2, 2021, 10:45Project manager. Ha!
I'll write more later, but for now - shame we didn't get to chat Pete, I also tried a couple of times but you were speaking with someone else or not there. Never mind!
Couple of vids:
And later in the session when Port Froid was flat. Not comfortable, but a lot of fun on the ditchfinders!
Have some data to look over too, which should be interesting.
Haha brilliant, looks so much fun. Lap times look quick also, 1:14's maybe...on ditch finders too. Very similar times to mine last time out at Blyton (pre-track layout tweak) and I was on AR1's, just shows you don't need fancy rubber to go quick, driver skill can easily make up for the lack of grip available.
Quote from: Maurici on July 2, 2021, 10:33Ah. You were there with the posh mr2 silver, green, massive gay wing... :P
Pretty sure it was Me in front of you. Dont tell me you was holding back, i was sooooo excited you could not keep up.
You have just ruined my day. Bollocks.
We stiffened the rear ARB to avoid body roll and again toe out in bump... a bit counter-intuive, and i wasnt sure about it but adam was convinced it would work. And it did.
I know what you mean with the difference of flat and flat-ish... I have driven blyton with several CRAZY power cars and posh tyres and yes there is a difference at the end. But... is only a super cheap trackday tool, and with the eco tyres is so fun. What is the point to make it faster? We have other toys for that.
Not sure of the future direction... Adam is the project manager there, but ill be very suprises if i ever see any posh rubber in that car.
Yeah that was my MR2
Sorry, Yeah you car was quick when you intially get on the power , but I was short shifting around 7.5k and holding right back into corners as yours was going so sideways I didn't want to "push" you into spinning in and then me pile into you.. but I had a lot of fun watching the MR2 going very sideways, not sure my passenger at the time liked it, he got a bit worried :) :)
On the way to Blyton my nephew wanted to know how much i had spent on my MR2, it was pretty eye watering, yours is a much lower buck option and i love it, it is quick
ECO tyres for the fun you were having is perfect. It did look at lot of fun! Maybe keep eye out for some used track tyres, they tend to be cheap and a good budget but be a great step up for the car
I compete in mine so i spend too much on it :), but i love it. Ended up doing loads a passenger laps too, they seemed to enjoy it
I was really surprised how quick it was in the straight compared to a normal 1zz, but you have lost soo much weight, like said with a 2zz box I reckon it'll be slightly quicker than a 2zz on the straight,
TBH I have an ECU and a lot of weight out and development in mine, so you are probably quite a bit quicker than a stock 2zz as your are
next time on track together i'd love to go out in it, happy to take you out in mine too if you ever fancied it
what are your next plans with the car?, or just run as is and enjoy!
Quote from: AdamR28 on July 2, 2021, 10:45Project manager. Ha!
I'll write more later, but for now - shame we didn't get to chat Pete, I also tried a couple of times but you were speaking with someone else or not there. Never mind!
Couple of vids:
And later in the session when Port Froid was flat. Not comfortable, but a lot of fun on the ditchfinders!
Have some data to look over too, which should be interesting.
top work bet it was scary on eco tyres going Flat! good work i'll watch when i get home from work
Yeah defo catch up next time! It is great to see what a mk3 can do with some weight loss, stock engine and a couple of good drivers
Quote from: pistol pete on July 2, 2021, 11:28Sorry, Yeah you car was quick when you intially get on the power , but I was short shifting around 7.5k and holding right back into corners as yours was going so sideways I didn't want to "push" you into spinning in and then me pile into you.. but I had a lot of fun watching the MR2 going very sideways, not sure my passenger at the time liked it, he got a bit worried :) :)
I'm now crying in a corner. I'll never get over this!
Glad you found it fun tho! :)
Quote from: Maurici on July 2, 2021, 12:40I'm now crying in a corner. I'll never get over this!
Glad you found it fun tho! :)
I'm sure you'll be fine. :) just go do another trackday and overtake all them cars you were going past (especially those pesky MX5s that were everywhere!)
It was properly well driven, it is always good seeing an MR2 going sideways, the amount of people saying it can't be done etc etc, you prove it can be
I had the wrong set up and tyres in the damp done most of silverstone GP circuit sideways, that was a lot of fun
Quote from: pistol pete on July 2, 2021, 13:04Quote from: Maurici on July 2, 2021, 12:40I'm now crying in a corner. I'll never get over this!
Glad you found it fun tho! :)
I'm sure you'll be fine. :) just go do another trackday and overtake all them cars you were going past (especially those pesky MX5s that were everywhere!)
It was properly well driven, it is always good seeing an MR2 going sideways, the amount of people saying it can't be done etc etc, you prove it can be
I had the wrong set up and tyres in the damp done most of silverstone GP circuit sideways, that was a lot of fun
Sadly, the camera in that session was not on. I´ve salvaged some of the fun stuff when I had the camera on...
The MunteR2 in all its glory
https://www.flickr.com/photos/frankhall/sets/72157719490115241/with/51285457244/ (https://www.flickr.com/photos/frankhall/sets/72157719490115241/with/51285457244/)
Glory. Now that's not a word I expected to see in this thread :)) Thanks for the link
@JB21 Thanks also for the kind words Phil and Pete - the car is pretty 'mobile' if you want it to be, but can be driven neatly as I hope my vids show. I know you don't always get on track with everything, but I had nothing at all come past all day and managed to keep up with the boosted kit cars (with the help of a little traffic ;) ).
It'd be awesome to have a blast in your car
@pistol pete and you would be very welcome to have a go in the Munter too - thanks!
As we have discussed before,
@Maurici has a certain Mediterranean flair when it comes to pedalling a car round, so the car does tend to make some quite funky shapes >:D During the afternoon he really got the hang of it and seemed to enjoy the car more (I hope so anyway mate!). I find that the transition between brakes and throttle has to happen just a tiny bit sooner than something like an MX5 - I guess that is down to the rear weight percentage - and if you hang on too long before transitioning you really get stung with a big slug of oversteer. Tme it right though and the car dances nicely with mild countersteering while on full power. Much fun.
Lap times... It turns out, same as Cadwell, the car ended up exactly the same pace as Munter Mk1 (on slicks - and the layout tweak at Blyton is a bit faster) with a couple of consecutive mid 1:14s not displaying on the datalogger that I didn't have in the car at all at any point. Cough. I have no doubt Mr Poo would be faster on some proper tyres, but then it would go through brake pads faster, put more load through the ageing suspension components, need a second set of wheels for when its really wet, and give more chance of oil starvation - especially not comfortable with this as it can burn 200ml in a long session! Weird that it doesn't appear to belch out any smoke though (thanks Pete).
I also feel that being mid-pack on a track day is the best place to be. For a competition car, sure, make it as fast as you can, but minimising the amount of overtakes (both overtaking and being overtaken) seems to make track days more enjoyable. I've tried both ends of the spectrum (completely bog standard 1.0L Micra & 550bhp/ton kit car on slicks) and decided I like being mediocre ;)
Having just one set of wheels / tyres is much less of a pain too, again for competition having wets and drys and something in between is ideal, but to just turn up, burn some fuel, share the car with some mates, and go sideways a bit no matter what the weather I think it works well. I can't say I'm not tempted by some 888s or AR1s or something, but I am 99% sure the next set of tyres that go on with have 'ECO' on the sidewall again!
On that note: that's 4 days completed now, 1 of them very wet, another half wet, and 2 dry (a pretty good approximation for the UK!), and the tyres look to have over half tread remaining overall - they'll easily do another 4 days. I figure that to £35's worth of tyres per track day, which will do nicely. Obviously the rears wear faster cos there's more weight there, but with them all being on the same wheels and the same tyres I have just rotated them. Blyton is a good one for evening out left-right tyre wear too!
Brake pads... the rears started wearing a bit too fast at Blyton, they're a bit over half done now (fronts still no visible wear). It was a hot day, Blyton is hard on brakes, and I think we reached the top of their 'window'. The rear brakes also definitely lock first if you really press on too, so the planned tweaks are: Step 1) fit that bias valve, Step 2) add brake cooling if that doesn't even out the wear. Average cost per track day: about a fiver.
Damping... we actually took a bit off the damping (now at 0.5 turns from full stiff all round) and the car felt better because of it. May go softer again next time as it is still way stiffer than the theory dictates and I run other cars.
I had been trying to use a lot of rebound to calm the car down during those crazy 'fling itself off the track backwards' oversteer moments, but as Maurici said above it turns out that seems to have been almost exclusively down to dynamic toe at the rear. With the rear ARB stiffened up (I modified the drop link and added an adjustable clamp) it really settled the car down on power / corner exit, while (as you would expect) also making the front end point in with more gusto.
Oil consumption - seems about the same, maybe a little better. Got through about 40L of fuel and didn't use a full 1L of oil, more like 750ml this time. Other than oil and fuel, the car needed nothing all day once again 8) Fuel and oil cost per day: About £60
Have settled on 35 front and 40 rear for tyre pressures. The car drives just fine like this and tyre wear is pretty even. Obviously the very outside edges are getting a bit feathered but that's to be expected!
Total track day 'normal consumables' cost: Approx £100. I'll take that, and suggest nobody else does the same maths in a fully honest way if you don't want a shock :))
Great write up Adam, and totally agree that mid-pack is most fun on track days. I always seem to put in my fastest lap of the day chasing faster cars.
How come your tyre pressures are so high compared to OE spec? I currently only run 26 front and 30 rear with AR1's, you reckon these should be bumped up?
Quote from: AdamR28 on July 7, 2021, 09:16As we have discussed before, @Maurici has a certain Mediterranean flair
I genuinely dont know what you are talking about.
Phil, I run them so hard to get a bit more feedback from the tyre and stop them wobbling around. The sidewalls are a lot less stiff than a proper track tyre, so you need the extra pressure to add stability. The tyres are effectively a spring - sidewall stiffness plus air pressure stiffness. I would say you're in the right window for the AR-1s, defo.
I did a bit of YouTube stalking from your latest Blyton lappage (slightly tweaked / faster layout for my lap) - basically it looks like we need to get together on track sometime and have a play (with you in front so I can have a tow and try to keep up)!
BlytonCompare.jpg
@JB21 Also grabbed a screenshot of the data from two consecutive laps after lunch. Pleased with the consistency, and that braking and lateral Gs are now clsoer to each other (confirms I was being a wuss on the brakes previously!).
Blylaps.jpg
Quote from: AdamR28 on July 11, 2021, 13:25Phil, I run them so hard to get a bit more feedback from the tyre and stop them wobbling around. The sidewalls are a lot less stiff than a proper track tyre, so you need the extra pressure to add stability. The tyres are effectively a spring - sidewall stiffness plus air pressure stiffness. I would say you're in the right window for the AR-1s, defo.
I did a bit of YouTube stalking from your latest Blyton lappage (slightly tweaked / faster layout for my lap) - basically it looks like we need to get together on track sometime and have a play (with you in front so I can have a tow and try to keep up)!
BlytonCompare.jpg
@JB21
Also grabbed a screenshot of the data from two consecutive laps after lunch. Pleased with the consistency, and that braking and lateral Gs are now clsoer to each other (confirms I was being a wuss on the brakes previously!).
Blylaps.jpg
Love it Adam. I do exactly the same things with data, very close indeed. 100% we'll get out, let me know once your booking and I'll jump on it with you.
We'll go out and do a few laps, with you on your eco specials, me on AR1's or slicks. Then come back in and you can lend my wheels with AR1's or slicks and I'll go out on your eco specials, just to see the difference.
Then you can take my car out on slicks and show me how its done. I reckon you could push a 1:09 with optimum conditions👌
Well, a bit of a bump here! The car has done the odd track day since the last post, but we've been too busy enjoying it to do write-ups etc. I think I have some clips from Oulton though, which I will dig out and upload.
Handling has been calmed down significantly with the addition of more rear toe in, and the oil consumption issue has reduced somewhat too. I'd say it's more of a 1-and-a-bit stroke than a 2 stroke now, if you see what I mean! So, consistent high rpm / load running *can* start to unstick the rings 8)
I've also decided to downsize my fleet so would like to move the car on. If anyone on the forum wants it, I'll take offers in the region of £1200, and happy to attend a track day with you to help you get comfy with the car.
I've priced it such that even if you don't like it, you could break it and recoup your money (and maybe more) from:
- Koni Sports with Tein springs (I bought them new so they've not done a lot of work)
- GRP kit car seats and Schroth harnesses
- 6 speed gearbox which works perfectly
- Rear subframe is in great condition
- Wishbones, radiator, front brake calipers (rear ones have no handbrake function), fuel tank etc obviously all work well
- Custom PPE style 4-1 stainless mainfold / exhaust, no cat, makes about 98dB, ideal for track / race car
- Wheels / tyres (14" MX5 alloys)
Every body panel has some sort of hole / dent / damage so they would only be fit for the scrap man.
Of course, I'd love to see the car used as a track hack like I have, but I'm just thinking practicalities as I know this sort of thing is not for everyone!
Any questions shout up :D
Quote from: AdamR28 on June 30, 2022, 14:13Well, a bit of a bump here! The car has done the odd track day since the last post, but we've been too busy enjoying it to do write-ups etc. I think I have some clips from Oulton though, which I will dig out and upload.
Handling has been calmed down significantly with the addition of more rear toe in, and the oil consumption issue has reduced somewhat too. I'd say it's more of a 1-and-a-bit stroke than a 2 stroke now, if you see what I mean! So, consistent high rpm / load running *can* start to unstick the rings 8)
I've also decided to downsize my fleet so would like to move the car on. If anyone on the forum wants it, I'll take offers in the region of £1200, and happy to attend a track day with you to help you get comfy with the car.
I've priced it such that even if you don't like it, you could break it and recoup your money (and maybe more) from:
- Koni Sports with Tein springs (I bought them new so they've not done a lot of work)
- GRP kit car seats and Schroth harnesses
- 6 speed gearbox which works perfectly
- Rear subframe is in great condition
- Wishbones, radiator, front brake calipers (rear ones have no handbrake function), fuel tank etc obviously all work well
- Custom PPE style 4-1 stainless mainfold / exhaust, no cat, makes about 98dB, ideal for track / race car
- Wheels / tyres (14" MX5 alloys)
Every body panel has some sort of hole / dent / damage so they would only be fit for the scrap man.
Of course, I'd love to see the car used as a track hack like I have, but I'm just thinking practicalities as I know this sort of thing is not for everyone!
Any questions shout up :D
Shame you're selling up Adam :(
Yeh, that is a great shame - I used to enjoy reading and watching your vids and how you were getting on with it Adam.
Change is inevitable.
Very happy to read that Adam is offering the fun to be continued at a bargain.
Sad news Adam, but nothing lasts forever. Hopefully someone snaps the munter up for some fun
Bit of a bump... but a year and a bit on, and the car hasn't turned a wheel again since. Which is a shame, but life moves on and I would still love the car to move on to another good home.
Price is still the same, deal is still the same. Any takers for some cheap winter fun? ;D
Appreciate this is hardly the best advert ever, but I will get round to creating one soon!