Super/turbo charged options

[nads1978]

Hello, I'm new here & think this is the place to be asking the following questions!

I recently sold a 520bhp Evo6, and would like something different, a MK3. I know that sort of power from a MK3 standard engine is a tall ask, I don't want 6/8 cylinder engines.

I'd like to get a mk3 MR2, what 4 cylinder engine options are available to fit pretty simply in the MK3?
I would like around 350 bhp (@ fly) which must be reliable and quiet (for motorways), as a daily driver (although just a toy).
Any ECU considerations? The intercooler would be a roof mount (RS200 replica).

I have only just started learning about the MR2 so excuse my ignorance, there is a lot to take in (chassis codes, engine codes)!

Many thanks, Nads.

[stargazer30]

MattPerformance on here has a build thread for this track car and is in the 350bhp range IIRC.  You are looking at serious £ and work to get that out of the 1ZZ engine in the MR2 though.  Regular turbos kits for our cars are about 200-250bhp ish.  Above this you start needing stronger engine internals, gear box upgrades, better bracing, a very strong clutch and so on.

Roof mount intercooler?  you do know the engine is in the rear right?   s:lol: :lol: s:lol:    Our coolers go infront/under the gear box usually.

More importantly though, do you have any experience driving mid engined rear wheel drive with no driver aids?  Its a whole different ball park to the fly by wire, heavily assisted evo you had before.  With that kind of power an MR2 will try and kill you if you screw up, and screwing up in our cars can be as easy as a tad too much throttle on a wet day, with the steering not straight.

[stupink]

From what i've seen you can just use the std 1zz engine, new rods/pistons,  the usual turbo kit, and then 350hp should be achievable and reliable. the gearbox won't be. so you'll want to look at options for that.
350hp should be about right for what you want imo.  im coming from 400hp but in a lighter car than an evo, so im aiming for about 300hp at the fly on mine, saves me (at least the first time around) doing the rods and pistons etc.  just build a spare engine in the garage to transplant in when it pops.
Not sure you need to faff around with a engine conversion.

assuming you did your evo yourself, you'll know what needs changing mostly.  s:) s:)  pretty much the usuals.    get the car first and drive it, you'll find it horrificly under powered, yet strangly illuring also at the same time, and perhaps it may squew your thoughts on how much extra power you need and you can save some more pennies and just keep it circa 300  s:) s:)

[Anonymous]

From what i've seen you can just use the std 1zz engine, new rods/pistons,  the usual turbo kit, and then 350hp should be achievable and reliable. the gearbox won't be. so you'll want to look at options for that.
350hp should be about right for what you want imo.  im coming from 400hp but in a lighter car than an evo, so im aiming for about 300hp at the fly on mine, saves me (at least the first time around) doing the rods and pistons etc.  just build a spare engine in the garage to transplant in when it pops.
Not sure you need to faff around with a engine conversion.

assuming you did your evo yourself, you'll know what needs changing mostly.  s:) s:)  pretty much the usuals.    get the car first and drive it, you'll find it horrificly under powered, yet strangly illuring also at the same time, and perhaps it may squew your thoughts on how much extra power you need and you can save some more pennies and just keep it circa 300  s:) s:)

A very good map and a very awear ecu, incase something does start to play up. You might find 300 possable on a std engine and it lasting.

[markiii]

Anything above 250 at the crank good luck on stock internals

[jonty]

If you want that sort of power I'd consider getting a 2zz engine (from celica 190/corolla/elise) and building that. The pistons aren't strong enough for 350bhp, but everything else is and the head design is way better than 1zz. External dimensions are the same for the two engines and you only need a different exhaust manifold and 1 engine mount bracket and it'll drop in, gearbox and driveshafts and all.

[loadswine]

I think you may be considering the wrong car really, with the power goals specified. A Mk2 turbo would be a better starting point if numbers are what you are after. You could put a 3s-gte lump in a Roadster, but it will still require modding and needs a lot of work to achieve properly. Handling will be significantly different too.
I totally agree with Mark, much above 250 on stock internals and it starts getting iffy on engine and gearbox life.
Plus if you have the sort of power mentioned, in a Roadster, you will need to be pretty skilled. I know we have driving gods on car forums, but it will definitely be a handful. It will be nothing like an Evo to drive or control.

[Wabbitkilla]

Big numbers are not what the Roadster is about, remember it only weighs about a ton (depending on years it's either just above or just below). The Roadster is about handling ability and balance. 250bhp can feel like a lot and certainly surprises more powerful and exotic cars in the real world. Sounds like you would be happier in an evo if numbers are everything to you.

[vinp182]

Anything around the 200-220 mark in a roadster will upset bigger powered more expensive cars..... Including Audi R8 and Evo's   s:wink: :wink: s:wink:

[stupink]

Anything around the 200-220 mark in a roadster will upset bigger powered more expensive cars..... Including Audi R8 and Evo's   s:wink: :wink: s:wink:

It's all very subjective. my mk3 was about 200 when I picked it up, and it just felt like a snail, I see you have a mk2 with some decent power, my mk2 na with 160hp used to loose a lot of more powerful cars, but you still have 400... and i'd agree that's a good thing..  the mk3 is no exception imo, I agree the powers not needed around the bends, but if it takes an hour to get to the next corner, or you pull out the bend and then just sit there maintaining your current speed, that just spoils the fun on track especially  s:) s:)

Random thought I just had to solve the contradictions caused by this chassis, would be to have some kind of boost/power controller that worked instead of off the gears or speed, but off the steering lol...   the more you steer, the less power you have available  s:lol: :lol: s:lol:    s:lol: :lol: s:lol:

[Anonymous]

Anything around the 200-220 mark in a roadster will upset bigger powered more expensive cars..... Including Audi R8 and Evo's   s:wink: :wink: s:wink:

It's all very subjective. my mk3 was about 200 when I picked it up, and it just felt like a snail, I see you have a mk2 with some decent power, my mk2 na with 160hp used to loose a lot of more powerful cars, but you still have 400... and i'd agree that's a good thing..  the mk3 is no exception imo, I agree the powers not needed around the bends, but if it takes an hour to get to the next corner, or you pull out the bend and then just sit there maintaining your current speed, that just spoils the fun on track especially  s:) s:)

Random thought I just had to solve the contradictions caused by this chassis, would be to have some kind of boost/power controller that worked instead of off the gears or speed, but off the steering lol...   the more you steer, the less power you have available  s:lol: :lol: s:lol:    s:lol: :lol: s:lol:

if you had an ecu controlled boost controller like the emerald ecu, you might find that possible to have a device to input a signal that you ecu uses to set the boost level.

[vinp182]

Anything around the 200-220 mark in a roadster will upset bigger powered more expensive cars..... Including Audi R8 and Evo's   s:wink: :wink: s:wink:

It's all very subjective. my mk3 was about 200 when I picked it up, and it just felt like a snail, I see you have a mk2 with some decent power, my mk2 na with 160hp used to loose a lot of more powerful cars, but you still have 400... and i'd agree that's a good thing..  the mk3 is no exception imo, I agree the powers not needed around the bends, but if it takes an hour to get to the next corner, or you pull out the bend and then just sit there maintaining your current speed, that just spoils the fun on track especially  s:) s:)

Random thought I just had to solve the contradictions caused by this chassis, would be to have some kind of boost/power controller that worked instead of off the gears or speed, but off the steering lol...   the more you steer, the less power you have available  s:lol: :lol: s:lol:    s:lol: :lol: s:lol:

400hp is awesome in a straight line............. but I thought we were talking real life driving   s:wink: :wink: s:wink:  Our mk2 V6 is the heaviest and lowest power car we have and its probably the most fun to drive round the twisties IMO

[jonty]

Just because the car is hideously underpowered as a trackday car in standard form doesn't mean that you have to leave it that way.

It is a bit of a pain to get the power from it, hence my suggestion of going 2ZZ. The MR2 mk3 does have fewer off the shelf (or tried and tested) ways of making big power compared to a lot of cars, but I don't think it's too outrageous to look for those numbers. You'll love the MR2 to for not going through tyres and brakes every trackday (and when you need to replace them you'll love the lower cost of the smaller brakes that they run) and that spare cash can be used to help develope the car!

[s12vea]

I think most people looking for big power out of a roadster need to understand what costs are going to be involved first - also having experienced many different setups of varying power it's more about the drivability and delivery that outright power. 200bhp is a sweet spot for the roadster and anyone looking for more should have a drive in a few circa 200bhp cars before making claims for wanting silly power.

[mrzwei]

As has been said, this can never just be about power.

Caterham 7 Superlight R500
263 BHP / 1115 lbs = 0.235 P/W
0-60 2.88 secs
150 mph

Ferrari F12 Berlinetta
730 BHP / 3362 lbs = 0.217 P/W
0-60 3.15 secs
211 MPH

(Ask Men 7/13).

[jonty]

I completely agree mr zwei, power to weight is king...

To want a power figure that gives 60-70% of the bhp/ton of those cars doesn't sound too unreasonable. 200bhp/ton is a sweet spot provided you've not had to come down from 350/ton in my opinion!

[loadswine]

Probably, if a 200hp Roadster is too slow for anyone, then you really have bought the wrong car. Save the money on upgrades and just buy a faster car, would be the best advice.

[jonty]

The other options for me are vx220 or elise, and i can build a faster, more individual mr2 cheaper than either of the other options. (though vx turbo would be pretty close on price I guess)

It seems to me it is a self perpetuating thing - we try put off the people who have the enthusiasm to develop and prove out the more extreme tuning options, and then it remains forever true that to tune an mr2 mk3 to 300-400bhp is a trip into the unknown and best avoided.

Just look at the honda tuning scene- there are plenty of people prepared to take a leap of faith with a turbo or supercharger, and so this encourages tuners to develop bolt on kits. Contrast that to the 1 UK based turbo kit that is no longer produced, and no one making a bolt on rotrex kit... Honda engines are not any better suited to being turbocharged- it's just the owners are more open minded and don't tell each other that if they want more than 200bhp they've bought the wrong car....

[Anonymous]

I agree with jonty so many people told me my compression ratio was to high but yet I still turbo'd it and it works. I think as a club we should support people the best we can and if we can't help just stay quiet. Was muffdan or markiii  told they were being stupid?

[vinp182]

I don't think anyone is telling anyone else not to do something to their own car. People are just giving advice from the experience of what's already been tried and tested and failed

Facts are that without forging a 1zz the figures that are wanted are not going to be met. It's been tried

My own opinion is that 200bhp in a roadster is perfect (I've had more and less). But that's just my opinion and that shouldn't matter to anyone wanting more  s:) s:)

I say go for it, I love a good project thread

[Wabbitkilla]

No I think it's only fair to point out what the engine is capable of handling in standard form.

A safe turbo 240-250bhp is achievable without modifying the engine internally, considering you have added 100-110 bhp to the standard output that's pretty impressive. There are very few engines you can do that to.

300bhp can be achieved on a standard engine but it's life will be reduced (it won't go bang immediately), but the gearbox seems to have a 300bhp ceiling if you want longevity from it.

600bhp can be done with many internal modifications and you have to consider gearbox and driveshafts as consumables.

As long as people understand these things and it's within their wallet / expectations of component life then all is fine. Most people want a road car that is easy to maintain and service, so 250bhp makes a pretty rapid and fun road car that will keep the majority of people happy. I keep getting tempted by the turbo route, I have loved driving the examples I've driven, but then I've also loved driving my NA car on the edge of its performance. I would suggest doing some chassis preparation for turbo though, improve the brakes with better pads, braided lines, and dot5.1 fluid. A bit of chassis bracing and possibly suspension replacement. The higher bhp you go the more likely the car will bite you back too, remember that balance and go enjoy.   s:wink: :wink: s:wink:

[stupink]

Personally i dont understand the "wrong car" argument....  the 2 is one of the best handling cars for a budget, adding power disrupts the handling.. so its far better to start with a car that handles well, have the power unbalence it, and try to compensate for that, than to start with a car that doesnt handle in the first place.

It clearly doesnt need to be as much power, hence myself only looking for 3/4 of my previous car and the OP loosing a couple hundred also with mental targets.

I think the concept of the argument against assumes that having 100 additional HP will ruin the 200 you start with. it can be true, when you tune to extreme limits you end up with a gutless waggon until all hell breaks loose..  but 1bar boost is barely winding the turbo up and tuned/mapped correctly you'd get the same car up to 200hp but then an additional ammount *if* you request it.

Who here can honestly say that they would turn down an additional 100hp if they knew that the car would remain the same at 90% throttle as it currently is, and only deliver the additional hp if you request it?   have you never gone full throttle in a situation and thought.... come on girl just a bit more if you would  s:D s:D

[jonty]

Yes it's definitely good to point out the potential issues - but bearing in mind Nads is coming from a 500+bhp car, I doubt having to buy some pistons for £300 is going to phase him too much - a single aftermrket brake disc will cost that for the evo. The tone just seems to be a bit negative, even though the information is perfectly accurate. I think it would be much better to phrase like this- "You'll need to fit some forged pistons and rods for that power, but brand X can be bought for Y money from Z supplier".

Nads, there are several people with cars built to a decent spec on this forum, and many with a build underway. Also, newcelica.org is a great resource for 1zz and 2zz tuning since there are way more Celicas than MR2s, and the engines are common between the cars. Spyderchat.com also has the builds of several more powerful MR2s documented and the power you have as a mental target is more common, whereas here it's the exception not the rule.

[Star_69]

Good points mentioned above, but the OP is building an rs200 replica based on a mk3. I don't think they are buying a standard mk3 to tune to 350bhp, but hoping to get somewhere nearer the 440hp of the original and not feel like they are dead in the water compared to what they used to. Yes, it won't be cheap to get there, but very possible. There's a few peeps on here that have that sort of power, but as Jonty said internationally theres lots that run that high.

Look at the DNA guys.. the amount of money going into the body alone they are not going to get talked out of a realistic sounding v6 because it 'will ruin the character of the car' or 'its cheaper to boost it'. Its about building a fun replica, and more importantly what you want.

I can't think of any option available either transplant or FI that destroys what the mk3 is about (except perhaps a DNA kit -- kidding   s:D s:D  ). Its a fun, amazing handling go-kart/car and more power is never a bad thing however its delivered. You just drive it accordingly.

[mrzwei]

Good points mentioned above, but the OP is building an rs200 replica based on a mk3. I don't think they are buying a standard mk3 to tune to 350bhp,

Yeah, I always had that trouble with exams at school! Read the bloody question properly   s:lol: :lol: s:lol: