I know what they do, I understand how to tune them.
The question is how the little Spyder responds specífically.
Also the Sportivo kit goes to 23 front and 17 rear wheras Whiteline offer 22 front and 18 rear. Regardless of their respective stiffness, the diameter has the ´same´ relative effect; thicker is stiffer.
Overall experience with the anti roll bars tells me that I might want a slightly stiffer one at the rear as I like a bit looser réar end.
However, I do not want to assume that Toyata plays it safe with the TRD set up with OEM balance on the side of understeer.
Thís I why I turn to the first hand experience here.
How does the little Spyder respond to sway bar tuning?
Here a very informative thread from the forum, but I always want to know more, sorry...
https://www.mr2roc.org/forum/index.php?topic=67387.25
A perspective:
The diameters of the various available options.
They are afaik all soled bars so comparable.
It must be noted thet the stiffness increases with the square of the diameter increase.
Front/rear
Stock bars are 20/15mm 100/100
TRD Sportivo 23/17mm 175/165
Cusco 22/18mm 150/180-260 (the front is not adjustable and relatively soft because of a longer arm)
Whiteline 22/18mm 146 - 175/ 165 - 207 - 257 - 316
Intrax 25/22mm 244/463
Addco 25.4/22.2mm 261/481
May do the delta in stiffness later, now enjoying a cold vermouth and hot erotic writing from Antequera gf O:-)
Added the stiffness as an index number with stock as 100. The numbers do not reflect most being adjustable; thus being set to a bit softer/harder than the index number.
The numbers are surprising really.
The crux with ARBs is their balance, their stiffness relative to eachother.
It seems that the TRD set is aiming at the stock balance; just a bit less body roll.
The others are increasingly towards úndersteer! Bar Cusco which goes to oversteer.
To add to the weirdness, the Spirit MR-S was set up with a stock front bar and a Cusco rear which is supposed to be very stiff (not found the diameters yet). This is going for óversteer and that is what Asano san says.
Found Cusco bars. The Spirit car thus has 100 front - 260 rear. Totally the opposite way to most settings.
Oh and one footnote.
A 4 hole adjustment really is an 8 way adjustable bar.
There is no need to move a hole at both sides at the same time; it is perfectly ok to go one hole at óne side only. Thus you have an intermediate setting at your disposal.
Quote from: Petrus on October 20, 2020, 23:58A perspective:
The diameters of the various available options.
They are afaik all soled bars so comparable.
It must be noted thet the stiffness increases with the square of the diameter increase.
Stock bars are 15/20mm 100/100
TRD Sportivo 17/23mm 165/175
Cusco 18/22 150/180-260 (the front is not adjustable and relatively soft because of a longer arm)
Whiteline 18/22mm 207/146
Intrax 22/25mm 463/244
Addco 22.2/25.4mm 481/261
May do the delta in stiffness later, now enjoying a cold vermouth and hot erotic writing from Antequera gf O:-)
Added the stiffness as an index number with stock as 100. The numbers do not reflect most being adjustable; thus being set to a bit softer/harder than the index number.
The numbers are surprising really.
The crux with ARBs is their balance, their stiffness relative to eachother.
It seems that the TRD set is aiming at the stock balance; just a bit less body roll.
The others are increasingly towards úndersteer! Bar Cusco which goes to oversteer.
To add to the weirdness, the Spirit MR-S was set up with a stock front bar and a Cusco rear which is supposed to be very stiff (not found the diameters yet). This is going for óversteer and that is what Asano san says.
Found Cusco bars. The Spirit car thus has 100 front - 260 rear. Totally the opposite way to most settings.
Its not weird at all, they want to rotate the car with their foot and are prepared to catch it at all times. That way they can steer faster. I have watched one of their videos and the guy was facing the wall in 50% of the cases and steered the car with his foot. They have wider tires too, like 255 or something.
Quote from: Nvy on October 21, 2020, 11:37Its not weird at all, they want to rotate the car with their foot and are prepared to catch it at all times.
I get that for Touge as on the mountain tracks here oversteer is something you can catch/modulate but understeer ... not.
QuoteThey have wider tires too, like 255 or something.
Wider rubber indeed changes the balance. The FL´s slightly wider rear illustrates that in being a bit more understeered.
Btw, my car is equiped with lsd so will not loose traction with one wheel losing it.
Just answering the PM you sent me about the Whiteline sway bar.
The front is 2 position adjustable and the rear is 4 position adjustable. You want more adjustability for the rear because that is the most sensitive.
Before any of this people get sway bars for the wrong reasons. The purpose of the sway bars is for coarse adjustability for other variables you cant easily compensate for and to make a car tolerable for the street by being able to use softer springs for comfort or for a less then ideal road surfaces. A stiff car is not good for handling or comfort but a necessary evil which makes sway bars a good compromise solution.
The execution of using sway bars is dependent on the spring rates of your dampers and the tires as a whole system. Just throwing sway bars to the mix without taking into consideration your other mods can make things worse. If you want to get sway bars get the ones that have the most amount of adjustability to tune it.
The Sportivo bars were tuned as a complete system with the struts. You can use separate components in the system and improve on it but going outside of what the engineers intended will require some trial and error and that is why adjustability is key.
Quote from: Dev on October 21, 2020, 14:39The Sportivo bars were tuned as a complete system with the struts. You can use separate components in the system and improve on it but going outside of what the engineers intended will require some trial and error and that is why adjustability is key.
Thanks Dev.
This is why I decided nót mounting stiffer ones, in effect upsetting the stock set up.
Now I am going to Sportivo dampers/springs I think I should reconsider the sway bars as those were part of the balanced kit and yes, best the ones adjustable closest to the TRD set up.
Hello,
does anybody know the thickness of the TTE (=Eibach) ARBs ?
BR
Ralf
Quote from: ralf321 on October 21, 2020, 18:25Hello,
does anybody know the thickness of the TTE (=Eibach) ARBs ?
BR
Ralf
22 and 17, both three settings.
Here the TüV approval 2004:
http://www.mr2-tech.de/wbb2/index.php/Attachment/234-TTE-Stabilisatoren-AM27914-MR2-pdf/
Would be great if they were still for sale.... Eibach does not offer them either.
Hello Petrus,
they (Eibach) would still produce them, you only have to order 20 sets.
Price would be around €390.-/ set. I once tried to organize a GB here in Germany, but could not get enough people to order them.
BR
Ralf
Buenas Ralf.
The TTE/Eibach is basically covered by Whiteline with the latter having an extra adjustment at the rear.
Both the TTE and the Sportivo bars were thus sold under the Toyota banner. TRD USA sold the TTE ones as TRD bars in the States. The reason being the three way adjustment whereas the Sportivo bars have none.
The rain is costing me money. With the bridge in the garage swamped, I can´t do anything to my car but as I was prepared to, had the itch and thus pushed the button on a set of Whiteline sway bars. Delivery 5-6 weeks (cheapskate shipping option) so plenty of time to get the Sportivo shocks mounted and get accustomed to them.
I ordered a set of Whiteline's in the middle of September and they are not due until the end of November over here - not in a massive rush as I have plenty other things i'm doing but looking forward to testing them.
Quote from: tets on October 22, 2020, 14:00I ordered a set of Whiteline's in the middle of September and they are not due until the end of November over here - not in a massive rush as I have plenty other things i'm doing but looking forward to testing them.
Fingers crossed the eta I have will be met then.
Not in a great hurry either as I am a great believer of getting accustomed to changes before moving on to the next.
The problem with receiving them late in the year is that testing circumstances will be iffy. Over here most of the year is sunny, like 300 days/year, and warm tarmac.
Looking forward to your experiences with them.
Quote from: Petrus on October 22, 2020, 14:30Quote from: tets on October 22, 2020, 14:00I ordered a set of Whiteline's in the middle of September and they are not due until the end of November over here - not in a massive rush as I have plenty other things i'm doing but looking forward to testing them.
Fingers crossed the eta I have will be met then.
Not in a great hurry either as I am a great believer of getting accustomed to changes before moving on to the next.
The problem with receiving them late in the year is that testing circumstances will be iffy. Over here most of the year is sunny, like 300 days/year, and warm tarmac.
Looking forward to your experiences with them.
you may have seen a few of the lads at a twisty little circuit called 3 Sisters over here - I'm a member of a motor club that runs events there and I can hire it for testing for £90 per hour or £300 for a half day. Plus I need to have a cold wet set up as well as a dry warm set up so will serve a purpose whatever the weather
Quote from: tets on October 22, 2020, 15:45you may have seen a few of the lads at a twisty little circuit called 3 Sisters over here - I'm a member of a motor club that runs events there and I can hire it for testing for £90 per hour or £300 for a half day. Plus I need to have a cold wet set up as well as a dry warm set up so will serve a purpose whatever the weather
Is your´s equiped with lsd?
Quote from: tets on October 22, 2020, 14:00I ordered a set of Whiteline's in the middle of September and they are not due until the end of November over here - not in a massive rush as I have plenty other things i'm doing but looking forward to testing them.
Where did you order from? Mine came next day weirdly, just a few weeks ago.
I'd be up for some 3 Sisters action if you need numbers to make a half day / hour viable.
Quote from: Petrus on October 22, 2020, 16:08Quote from: tets on October 22, 2020, 15:45you may have seen a few of the lads at a twisty little circuit called 3 Sisters over here - I'm a member of a motor club that runs events there and I can hire it for testing for £90 per hour or £300 for a half day. Plus I need to have a cold wet set up as well as a dry warm set up so will serve a purpose whatever the weather
Is your´s equiped with lsd?
It is yes - I also have a JDM "special" LSD box on the floor to go in at sometime
Quote from: AdamR28 on October 22, 2020, 16:17Quote from: tets on October 22, 2020, 14:00I ordered a set of Whiteline's in the middle of September and they are not due until the end of November over here - not in a massive rush as I have plenty other things i'm doing but looking forward to testing them.
Where did you order from? Mine came next day weirdly, just a few weeks ago.
I'd be up for some 3 Sisters action if you need numbers to make a half day / hour viable.
I ordered them from Whiteline UK up in Scotland. It did say they were waiting stock when I ordered but no rush - plus I wanted contact to try and get there printing work!!
3 sisters is a club price for exclusive test days so I can pretty much go when I want as long as they have the marshals, medics etc on site
I was wondering if they'd rent the track for an exclusive day but you have to have the MSUK license and overalls etc for the above so they are insured by MSUK as far as I understand it - otherwise it's got to be one of the organised track days that have their own insurance unfortunately
Haha, nice idea!
Things have changed a bit since I last went for a test session then... rocked up, popped £60 cash in someone hand, they said they'd give me a shout in an hour when my time was up. That was it!
I think they still do that type of thing but the club one is unlimited track on and off when you want. Out for a few timed laps, in change settings and out again!
I have Cusco sway bars.
The rear is at 260% and my car is very balanced.
For the Spirit's MRS, all of the setup is specific like the dampers, the offset wheels...
All is important at this level.
But I was very curious to try more strenght for the sway bars for trackdays like Intrax or Addco.
But the price is expensive just for trying...
Quote from: tatieu on October 22, 2020, 20:19I have Cusco sway bars.
The rear is at 260% and my car is very balanced.
For the Spirit's MRS, all of the setup is specific like the dampers, the offset wheels...
All is important at this level.
But I was very curious to try more strenght for the sway bars for trackdays like Intrax or Addco.
But the price is expensive just for trying...
Depending on the angle of the linking rods you could try make a clamp adding an extra hole further inside.
Btw. it baffles me that you have the rear at 260% like Asano san and find the car balanced whereas many prefer one sófter than the front, even delete it at the rear!
That shoúld on comparable tyres be oversteer versus understeer, both on opposite sides of the almost neutral OEM bar setting.
I am getting really curious to try. Will have to wait a ´bit´ though :-(
It's been a while for me but when I was rallying I always set my cars up for oversteer. I'm really interested in how the MR2 will respond as I prefer catching the back than the front. If I can get it to turn in I'm of the opinion I can deal with the rear.
This has been with front and four wheel drive but the only engine over the back wheels car i've ever had was a 911 road car but I did used to drive that with the back end swinging
Guess it's just what you're comfortable with as a driver as to how you set it up
Quote from: tets on October 22, 2020, 22:00It's been a while for me but when I was rallying I always set my cars up for oversteer. I'm really interested in how the MR2 will respond as I prefer catching the back than the front. If I can get it to turn in I'm of the opinion I can deal with the rear.
This has been with front and four wheel drive but the only engine over the back wheels car i've ever had was a 911 road car but I did used to drive that with the back end swinging
Guess it's just what you're comfortable with as a driver as to how you set it up
As I wrote above, I am more comfortable without understeer but regardless I find the spread in sway bar stiffness front and rear unbelievable.
I can get the reach of stíffness but not thát stiff ut front with a lot less rear versus the reverse. Intrax/Adco are réally understeered whereas Cusco is as much over steered and Spirit ups that with the OEM up front. Thát wide a spread I don´t get.
The Spirit car nmay have wider rubber but it maintains the tyre stagger; 225 front, 245/255 rear so the sway bar balance is still as per OEM tyres.
Anyway, looking forward to play with it myself.
I would like to point out a significant perspective:
´Performance´ in the case of handling, brakes, roadholding is as much about speed as about safety. Better means safer as at the same speed the margin for error and/or the unexpected is wider.
My close shave Monday morning was a clear example: With less traction/roadholding and more weight I would have swiped the corner.
With a change in sway bars I aim to get a faster responding handling and more traction on the four wheels under real word road conditions using stock size summer street rubber.
I'm soon to fit some Whitelines... would the general consensus be to go full soft to start and work your way up?
My setup is :
195/50/15 & 205/45/16
At this point, it's necessary to compare the real size of the tyres because the AD08R like mine is really :
199 & 208
And it's necessary to compare the brand of the tyres too.
Quote from: Petrus on October 22, 2020, 23:10As I wrote above, I am more comfortable without understeer but regardless I find the spread in sway bar stiffness front and rear unbelievable.
I can get the reach of stíffness but not thát stiff ut front with a lot less rear versus the reverse. Intrax/Adco are réally understeered whereas Cusco is as much over steered and Spirit ups that with the OEM up front. Thát wide a spread I don´t get.
The Spirit car nmay have wider rubber but it maintains the tyre stagger; 225 front, 245/255 rear so the sway bar balance is still as per OEM tyres.
Anyway, looking forward to play with it myself.
The Spirit car is set up for a particular track, temp and general condition - tight twisty, bone dry and warm surface, sticky tyres etc etc
I bet if he tried that set up at Oulton Park in North West England in October he would be changing things!
Quote from: tets on October 23, 2020, 07:50Quote from: Petrus on October 22, 2020, 23:10As I wrote above, I am more comfortable without understeer but regardless I find the spread in sway bar stiffness front and rear unbelievable.
I can get the reach of stíffness but not thát stiff ut front with a lot less rear versus the reverse. Intrax/Adco are réally understeered whereas Cusco is as much over steered and Spirit ups that with the OEM up front. Thát wide a spread I don´t get.
The Spirit car nmay have wider rubber but it maintains the tyre stagger; 225 front, 245/255 rear so the sway bar balance is still as per OEM tyres.
Anyway, looking forward to play with it myself.
The Spirit car is set up for a particular track, temp and general condition - tight twisty, bone dry and warm surface, sticky tyres etc etc
I bet if he tried that set up at Oulton Park in North West England in October he would be changing things!
You´d win that bet so no dice ;-)
Those conditions btw, the Touge on youtube too, is what I have over here for most of the year, even on a January afternoon on the sunny south facing slope screaming up from La Viñuela up to El Boquete de Zaffaraya.
...and then next morning below zero with the windscreen all frosted up :-O
Also he can set up for an empty road. With traffic coming the other way you cannot set up for much oversteer.
Quote from: Petrus on October 22, 2020, 23:22I aim to get a faster responding handling and more traction on the four wheels under real word road conditions using stock size summer street rubber.
Then I would cancel your order for the sway bars, IMO, and fit some better dampers with more low speed compression and mild digressive valving - Koni Sport, for example.
Quote from: AdamR28 on October 23, 2020, 10:14Then I would cancel your order for the sway bars, IMO, and fit some better dampers with more low speed compression and mild digressive valving - Koni Sport, for example.
TRD Sportivo legs are about to be fitted today. The subchassis spacers (aka dog bones) are in already.
The complete kit includes a set of sway bars so looking to replicate that with adjustable bars suitable to my driving.
Sway bars work dífferently than shocks/spings btw. Unless you go for silly stiff ones, they have negligable effect on how the car is sprung and work more directly by/on weight transfer. As such they are an effective aid for balance of traction between front and rear. Because of the kinetics of rubber; the load sensitivity of the tyres, the load distribution can result in móre overall traction even.
I know.
Quote from: AdamR28 on October 23, 2020, 10:14real word road conditions using stock size summer street rubber.
This is important though...
Quote from: AdamR28 on October 23, 2020, 10:58I know.
Quote from: AdamR28 on October 23, 2020, 10:14real word road conditions using stock size summer street rubber.
This is important though...
Together with the personal driving style it = the sort of use = the parameters for the best matching balance.
similar to Petrus in the way the car is being set "for now" is 30mm lowered on very good stock struts (i know the TRD should be better), stiffer anti roll bars and i've bought the bar to make the dog bones. I'm also polybushing everything except the engine mounts but have opted for the sikaflex route here!!
i'm interested to find the different characteristics and understand them properly before I go coilover - thoughts being if I try everything at the same time i'll probably cock it up sufficiently to be slower on track!
I've been lowered 30mm with new standard bushes so have a handle on how the car reacts now - polybush and anti roll bars next and then i'm looking at BC ER coilovers for the start of the season. I did fancy XYX RS but having read more the BC's look a lot better spec'd, adjust compression and rebound plus they adjust ride height on the strut body, not the spring
I've said this many times on many various car forums, and it usually falls on deaf ears - but I'm repeating it here because the average level of intelligence is much higher than 'most forums'!
Consider the car and driver as one package. You might make the car 5% faster (that would be quite a jump - 3s per minute) by adding all of the go-faster bits you can find, but if the driver cannot exploit the performance, you may end up going slower.
Below is an example of that.
On the left is a 1.6 mx-engineinwrongplace with a completely standard 115bhp engine, 5.5" wide wheels on old 160 section slicks, Koni sport dampers, cut down and then re-welded because I cut them too short lowering springs, and a bunch of weight taken out to get it to 800kg (140bhp/ton).
On the right is a sprint series championship winning, 180bhp Honda CBR1000RR Fireblade powered Westfield, paddle shift, fancy electronics, stiff springs and ARBs, weighing 415kg on 8" front / 10" rear slicks (430bhp/ton). I know Simon pretty well and he is a good driver - has won his sprint class on a number of occasions, in various cars.
http://www.youtubemultiplier.com/5f7387023509c-munter-vs-blade-at-cadwell.php
(Give it a few seconds to pre-load before hitting play)
You have to be a very good driver once wheel frequencies get over ~2.5Hz, else you'll never be anywhere near the performance of the car, and how difficult it is to handle will actually hurt how fast you can pedal it. I'm not saying anyone is a bad driver - just this is something that needs to be considered carefully - the car and driver as a package!
Quote from: AdamR28 on October 23, 2020, 10:58I know.
Quote from: AdamR28 on October 23, 2020, 10:14real word road conditions using stock size summer street rubber.
This is important though...
His real world conditions are nothing like mine
Quote from: AdamR28 on October 23, 2020, 12:06http://www.youtubemultiplier.com/5f7387023509c-munter-vs-blade-at-cadwell.php
Beejeezes. The difference is só large that it took me some time to get a synchronised beginning (the first bridge).
Thanks for that!! Enjoyed it.
Ok, you can tell us now what magic sway bars you used :-)
Seriously, I totally get your point, obviously ;-)
Even fýsically so. See my observations about the need for a seat giving proper side support. Imo there is no way you can drive a car properly when hanging on to the steering wheel because slinding on the OEM leather.
Lastly I lóve your solution for the dilemma of laminated glass versus lighter weight plastic; visor tear offs.
Quote from: tets on October 23, 2020, 11:47i've bought the bar to make the dog bones.
Snelbaard has them in stock ready made on my request.
Quote from: AdamR28 on October 23, 2020, 12:06I've said this many times on many various car forums, and it usually falls on deaf ears - but I'm repeating it here because the average level of intelligence is much higher than 'most forums'!
Consider the car and driver as one package. You might make the car 5% faster (that would be quite a jump - 3s per minute) by adding all of the go-faster bits you can find, but if the driver cannot exploit the performance, you may end up going slower.
Below is an example of that.
On the left is a 1.6 mx-engineinwrongplace with a completely standard 115bhp engine, 5.5" wide wheels on old 160 section slicks, Koni sport dampers, cut down and then re-welded because I cut them too short lowering springs, and a bunch of weight taken out to get it to 800kg (140bhp/ton).
On the right is a sprint series championship winning, 180bhp Honda CBR1000RR Fireblade powered Westfield, paddle shift, fancy electronics, stiff springs and ARBs, weighing 415kg on 8" front / 10" rear slicks (430bhp/ton). I know Simon pretty well and he is a good driver - has won his sprint class on a number of occasions, in various cars.
http://www.youtubemultiplier.com/5f7387023509c-munter-vs-blade-at-cadwell.php
(Give it a few seconds to pre-load before hitting play)
You have to be a very good driver once wheel frequencies get over ~2.5Hz, else you'll never be anywhere near the performance of the car, and how difficult it is to handle will actually hurt how fast you can pedal it. I'm not saying anyone is a bad driver - just this is something that needs to be considered carefully - the car and driver as a package!
Good watch that and nice driving - 1 question, how much quicker would you have been in the Westy? serious question as I think you could pedal it quicker than it was being.
I get all of the above - I've set many rally cars up both rear and 4WD but never before with the engine in the back - Only car i've ever had rear engine was a 911 but that was a road car.
I have a certain style which will differ from yours, petrus' etc etc so need to be fully aware of how things react before I go to the next stage hence doing it in stages.
Main thing i've always started with is getting a set up i'm confident with ignoring the clock and working from there
no point gaining half a second if you're shitting yourself coming out of every bend wondering when you're going to bin it!
Quote from: 1979scotte on October 23, 2020, 12:25His real world conditions are nothing like mine
Just at the far, north, side of the village, 2 km from my farm, the road connects to Archidona. It has thréé sections that are like the Touge videos stretch. Different from eachother and again vastly different when done from Archidona. Basically síx stretches of twisty mountain bits.
It is open road ofcourse so you nééd to take every corner as if there will be a car coming the other way and you can for the same reason NÓT be on the limit, but even so it´s challenging fun. The limit being thát driver in thát car.
Because of the inherent unforseeable character of the unexpected on the open road the car must be more forgiving.
Quote from: tets on October 23, 2020, 12:44no point gaining half a second if you're shitting yourself coming out of every bend wondering when you're going to bin it!
Haha, pretty much!
That specific Westy? I don't know. I don't enjoy driving really stiff cars, or ones that have terminal understeer (I often see this as a 'symptom' of the car being so stiff that the driver can't manage it, so they go for a super safe setup).
My Westy of similar spec, but with much more manageable handling? About 10s quicker. BUT I have learned to drive like that from years of bashing about in soft / compliant cars, then translated it into stiffer ones.
It's worth calculating wheel frequencies, that will give you a really good idea of how the car will handle. OptimumG website has some good, easy to follow articles:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjIr_bl08rsAhXFUhUIHYE8AQgQFjACegQIBRAC&url=http%3A%2F%2Fdownloads.optimumg.com%2FTechnical_Papers%2FSprings%2526Dampers_Tech_Tip_1.pdf&usg=AOvVaw3l2iwo6KRAzVgIDJEO39_t
Change Tech_Tip_1 for Tech_Tip_2, 3, 4, 5 etc to get them all.
Quote from: AdamR28 on October 23, 2020, 12:55https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjIr_bl08rsAhXFUhUIHYE8AQgQFjACegQIBRAC&url=http%3A%2F%2Fdownloads.optimumg.com%2FTechnical_Papers%2FSprings%2526Dampers_Tech_Tip_1.pdf&usg=AOvVaw3l2iwo6KRAzVgIDJEO39_t
Thanks.
Wáy easier to digest for me than Milliken.
Quote from: AdamR28 on October 23, 2020, 12:55Quote from: tets on October 23, 2020, 12:44no point gaining half a second if you're shitting yourself coming out of every bend wondering when you're going to bin it!
Haha, pretty much!
That specific Westy? I don't know. I don't enjoy driving really stiff cars, or ones that have terminal understeer (I often see this as a 'symptom' of the car being so stiff that the driver can't manage it, so they go for a super safe setup).
My Westy of similar spec, but with much more manageable handling? About 10s quicker. BUT I have learned to drive like that from years of bashing about in soft / compliant cars, then translated it into stiffer ones.
It's worth calculating wheel frequencies, that will give you a really good idea of how the car will handle. OptimumG website has some good, easy to follow articles:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjIr_bl08rsAhXFUhUIHYE8AQgQFjACegQIBRAC&url=http%3A%2F%2Fdownloads.optimumg.com%2FTechnical_Papers%2FSprings%2526Dampers_Tech_Tip_1.pdf&usg=AOvVaw3l2iwo6KRAzVgIDJEO39_t
Change Tech_Tip_1 for Tech_Tip_2, 3, 4, 5 etc to get them all.
I can't work with understeer either and tend to find neutral / slight oversteer on tarmac works best for me.
Back to the topic, this is why I need to understand how adjustable anti roll bars react first in this car on smooth tarmac with my current set up (plus the polybush)
I might find I prefer it with the softer damping but I just can't see it - maybe in the cold and wet on a hillclimb it might be more compliant but on smooth dry tarmac i think i'll want more damping - we'll see and it will be fun testing it!
This afternoon was sales calls but you might have just cocked all that up with those tech guides!! haha
Quote from: tets on October 23, 2020, 13:14I might find I prefer it with the softer damping but I just can't see it - maybe in the cold and wet on a hillclimb it might be more compliant but on smooth dry tarmac i think i'll want more damping - we'll see and it will be fun testing it!
Wet-n-cold is slower going because of less traction and even simply thát; less traction, less kin.energy/lower forces, makes equivalent softer settings ´equal´ settings.
Wet-n-cold is slower going because of less traction and even simply thát; less traction, less kin.energy/lower forces, makes equivalent softer settings ´equal´ settings.
[/quote]
I can only relate to rallying front engine cars at the minute but braking force on dry tarmac shifts more weight to the front tyres and better turn in - In the wet I used to soften the front as less braking force less shift but a bit of dive used to do the trick for me - Again my experience in my old cars
Don't know if it will work in this car but we'll see. I know everyones experience in different cars, in different conditions with different styles differs
Just have a look at the brake rotor sizes: The rear ones are larger; 43/57 front/rear weight distribution.
The Lotus Elise has even more rear weight bias.
Both deliberate!!! whereas common internet wisdom is that 50/50 is best ;)
Quote from: Petrus on October 23, 2020, 14:04common internet myth
Fixed that for you :D
Some 'ish' numbers:
40:60 weight distribution (close enough), like our little cars:
--> On the brakes, 50:50 - best braking possible
--> On the power, 35:65 - tons of traction
--> Mid corner, 40:60 - just get the ARB and spring rates right and it'll work just as well as 50:50
Apologies for filling the thread with slightly tangential stuff - I have no direct experience of changing ARB rates on an MR2, yet - but I haven't yet found a car that can be driven quickly, consistently and with confidence, in a range of conditions, by the average driver, where the roll stiffness is more than approx 1.5deg/g (degrees of body roll per 1g of cornering load), or 2.5 degrees total body roll.
To put some comparisons on that, with approximate maximum cornering loads...
Mk1 mx-engineinwrongplace race car with 500/300lb springs and standard ARBs: 2.5deg/g = 3.25 degrees @ 1.3g
The chopped up mx-engineinwrongplace in the above video is around 3.5deg/g = 5.25 degrees @ 1.5g
Standard Mk1 mx-engineinwrongplace is 5.5deg/g = 5.5degrees @ 1g
Standard K-Series S2 Elise is 3deg/g (approx 38:62) = 3.3 degrees @ 1.1g
The Elise with 'race' dampers and springs, 1.5deg/g = 2.25 degrees @ 1.5g
The car in the video below is 1.7deg/g = 2.4 degrees @ 1.4g (sprint class win by 4.5s in a borrowed car, having been ridiculed all day for having a car that was too soft, ha), approx 45:55:
The car below is 1.5deg/g = 2.4 degrees @ 1.6g, approx 43:57 (As you can see I gradually stiffened cars over the years (and went more rear weight bias) to the point where I think this is about the limit for an all-rounder):
The BEC Westfield in the comparison video above will be well under 1deg/g (under 1.5 degrees total)
F1 car, approx 40:60, and 0.5deg/g (2.5 degrees @ 5g)
From all of the above, I think we can fairly safely conclude that a total roll amount of less than 2.5 degrees is going to be hard to drive.
I can do the calcs for the MR2 or pop up my shreadsheet if anyone wants it, but I am pretty confident coilovers
and uprated ARBs will put an MR2 well under 2deg/g, and make it difficult to drive, especially if you then add sticky tyres which have less of a window between grip and slip than road tyres.
I would hazard a guess that standard the car is around 4.5deg/g, adding coilovers you'll be down to 2, and then adding any of the ARBs mentioned at the start of the thread will have you into the low 1.somethings on deg/g, and under 2 on total body roll.
(Just tagging you here Phil as you might find this interesting
@JB21 )
Quote from: AdamR28 on October 23, 2020, 14:28Apologies for filling the thread with slightly tangential stuff -
Aplogies accepted, please go on :-)
QuoteI can do the calcs for the MR2 or pop up my shreadsheet if anyone wants it, but I am pretty confident coilovers and uprated ARBs will put an MR2 well under 2deg/g, and make it difficult to drive, especially if you then add sticky tyres.
Again, please do.
On real world road surface I think the available after market springs are already a step too far. A softer car may be less direct/responsive, it also is more compliant and forgiving; the safety margins are wider and you have more time for everything, which I honestly nowadays prefer for peace of mind; things appear to go quicker than 30 years ago...
That and the simple fact I cánnot drop it 30mm for resulting lack of ground clearance :-O
The Sportivo legs are supposed to be 20mm lower and on my lighter car that will fingers crossed be less.
p.s. pleased me to no end to read that you chopped your springs. I took off half and just over half a coil to get the ride height back down to OEM.
I can do the calcs for the MR2 or pop up my shreadsheet if anyone wants it, but I am pretty confident coilovers
and uprated ARBs will put an MR2 well under 2deg/g, and make it difficult to drive, especially if you then add sticky tyres which have less of a window between grip and slip than road tyres. I would hazard a guess that standard the car is around 4.5deg/g, adding coilovers you'll be down to 2, and adding any of the ARBs mentioned at the start of the thread will have you into the low 1.somethings...
(Just tagging you here Phil as you might find this interesting
@JB21 )
[/quote]
It's interesting reading Adam and especially as i've never done sums first.
With the rallying the surfaces are so different stage to stage i've always done set up's by feel and conditions. i've always aired on a slightly softer set up as it can cope with more changes and once in a corner I can use my right foot to do a lot of the adjustment.
So much that coming off rough surface onto smooth tarmac in the past i've lifted the inside front as the back has been a bit too soft.
I'd love to do the maths here as it interests me. The thing with the circuits and hillclimbs once happy it all goes in a "little black book" for next time as a starting set up which I expect will be a bit stiffer than i'm used to.
Pitty we're on lockdown as you're only 1/2 hr away and wouldn't mind picking your brains (and spreadsheet) sometime!
That said, it will be a little while until i'm back on the road!
I don't think it's filling the thread as it's all relevant
Cool beans. Glad I'm not alone in enjoying this nerdy stuff! Ha O:-)
I'll have a do at bashing the MR2 in my spreadsheet then, see what pops out...
Nowt wrong with a bit of wheel lift IMO... here's me exiting Cascades at Oulton Park doing about 80-90mph in 4th gear (on 185 section Uniroyal Rainsports!):
2094906598_Adam3wheels.jpg.bd68bb37f79a43e5b1d3844745eba234.jpg
A front wheel in the air just means the inside rear wheel still has plenty of load on it = traction for days ;D
Quote from: AdamR28 on October 23, 2020, 15:11Cool beans. Glad I'm not alone in enjoying this nerdy stuff! Ha O:-)
I'll have a do at bashing the MR2 in my spreadsheet then, see what pops out...
Nowt wrong with a bit of wheel lift IMO... here's me exiting Cascades at Oulton Park doing about 80-90mph in 4th gear (on 185 section Uniroyal Rainsports!):
2094906598_Adam3wheels.jpg.bd68bb37f79a43e5b1d3844745eba234.jpg
A front wheel in the air just means the inside rear wheel still has plenty of load on it = traction for days ;D
Looking forward to the numbers!!
Great pic that is and nothing wrong with Rainsports, I have a set for wets as do a lot of the race lads!
Right, the Sportivo legs are under.
The ´ride´ hight ís a bit lower but static less than 10mm. and the springs are slightly firmer hence I put the ´ride´ between brackets.
Did do a shake down run and nothing shaked. The ride quality is definitely better but will do nothing remótely quick till I have the allignment sorted, hopefully Monday.
Nów I want the sway bars sooner ofcourse O:-) O:-)
Also looking forward to some MR2 numbers in your table Adam. I lóve numbers as it quantifies the science, making it easier to ´get´ and it provides a solid base for settings to depart from unlike the proverbial wet finger in the air ;)
Found spring rates:
kg/mm Front Rear
Stock 1.3 2.1
Sportivo 1.6 3.4
Note that the Sportivo rear springs have over double the rate of the front ones whereas the stock rear springs under half more.
TRD ´race´ springs are 2.4 and 4.7 kg, following the doubling of the rate.
Spirit S Asano san also advises this ratio for street set up although he suggests 5 and 10 kg. I dó now understand why he did not ungrade the front sway bar!!
Now the striking thing is that after market springs follow the stock ratio, just stiffer, ending up with the front stiffer than Sportivo and the rear softer.
That sure makes sway bar settings (for stock ratio or TRD ratio) different!
Quote from: Petrus on October 23, 2020, 21:50Found spring rates:
kg/mm Front Rear
Stock 1.3 2.1
Sportivo 1.6 3.4
Note that the Sportivo rear springs have over double the rate of the front ones whereas the stock rear springs under half more.
TRD ´race´ springs are 2.4 and 4.7 kg, following the doubling of the rate.
Spirit S Asano san also advises this ratio for street set up although he suggests 5 and 10 kg. I dó now understand why he did not ungrade the front sway bar!!
Now the striking thing is that after market springs follow the stock ratio, just stiffer, ending up with the front stiffer than Sportivo and the rear softer.
That sure makes sway bar settings (for stock ratio or TRD ratio) different!
I'm on TTE springs which after much research seem to be approx the same spring rates as stock, just 30mm lower
Quote from: tets on October 24, 2020, 07:01I'm on TTE springs which after much research seem to be approx the same spring rates as stock, just 30mm lower
By Jove, that is sériously less dynamic ride hight then :-O How much tyre rubbing do you experience?
TTE springs before and tein S now.
Rubbing on stock size rims and tyres = zero.
yep - no rubbing for me either
I had some before with OEM ride hight!! and still have now: Going véry fast trough a corner and hitting a depression/bump will have it rub a moment. Will reduce with the nagative camber and no doubt also with stiffer sway bars.
Silly speed level I will admit and nothing on the smooth. Very little smooth here though, especilly up and down:
Going up after down sees the car pressed down. Have that going fast through corner and... rubs.
A more tricky one is the crown between going up and down. The car gets lighter and has less traction. Have that going fast through a corner and... you prefer oversteer to understeer 8)
Have a mail to Whiteline outstanding; would like to know the % of torsional stiffness between the adjustments. Easy enough to calculate if I could méasure the bar but as I don´t have them quite yet...
Have received answer from Whiteline and they included a pdf with a cross ref chart.
The front bar is 146 175
The rear bar is 165 207 257 316
Thus front stiffest hole, rear softest hole would be equal to TRD Sportivo.
As a rule of thumb, LSD makes a step stiffer possible at the rear. The Spirit car obviously has LSD.
Asano san´s setting of the car is stock front, Cusco rear; 100 / 260.
Those numbers look... odd. Be interesting to see if my calculations match up! I'll let you know.
Quote from: AdamR28 on October 26, 2020, 11:00Those numbers look... odd. Be interesting to see if my calculations match up! I'll let you know.
They look awfully stiff.
The Whiteline pdf is clear though and it matches with the differences in diameters.
Mind that I take the stock braces as 100/100.
That makes 47% stiffer 147.
Hence 207, 207%, twice as stiff.
The rear though... uffff!
sway bar chart.pdf
Link here for anyone who has a set and wants to run the numbers more quickly than I can!
https://balancemotorsport.co.uk/suspension/anti-roll-bars
Edit: Just seen the PDF... I think we can pretty much ignore that, too generic.
Quote from: AdamR28 on October 26, 2020, 11:14Edit: Just seen the PDF... I think we can pretty much ignore that, too generic.
It is only for the values of the settings of the Whiteline bars. It is where the stiffness values I updated come from.
Quote from: AdamR28 on October 26, 2020, 11:14Link here for anyone who has a set and wants to run the numbers more quickly than I can!
https://balancemotorsport.co.uk/suspension/anti-roll-bars
There is one aspect missing: The angle of the link rod with the arm. At 90 degrees the torsional force is the most direct, largest. As the angle increases a larger part gets vectored alóng the rod, straining, pulling or pushing the bushing on the frame and that part of the force is not resulting in torsional resistance.
This, the angle resulting in force on the bushes, is why with extreme stiff bars/setting the mounting cán shear off.
I would guess that's too negligible to make much difference? Certainly with rod end type drop links and the sorts of angles we are talking about.
Quote from: AdamR28 on October 26, 2020, 14:49I would guess that's too negligible to make much difference? Certainly with rod end type drop links and the sorts of angles we are talking about.
Just had a look at the stock set up and a virtual hole either way would be in the order of 2 degrees.
Add another hole and make it 4,5 degrees on for calculatings sake 90 = 5%, indeed not an issue.
Also noticed a glitch in my reading of the pdf. Will need to have another look when back from the garage.
Done part of 'the numbers' today, using a handy website called vSusp. Some of these values plug into the ARB calc I have, then some numbers that come out of the ARB calc can plug back in here to figure out if suspension improvements can be made.
I take no responsibility for any of this being a load of old cobblers, it's hard to measure accurately and a few mil here and there can make a big difference - BUT in general it works out as I would expect: Toyota knew what they were doing, and lowering the car is bad! Bad for body roll, bad for camber correction, bad for handling (both steering feedback and 'snappy rear end').
This is pretty tech, apologies for all the numbers. I've tried to annotate to explain best I can.
Some wording used:
Roll centre: A theoretical point, derived from the suspension geometry, through which the loading acts during cornering. Green dot on vSusp.
Roll axis inclination: Imagine a line drawn from the front roll centre, to the rear roll centre. This is the roll axis.
Roll couple: The distance (and direction) between the roll centre and the centre of mass of the car. Think of it as a lever - force (the car being acted on by lateral acceleration) x distance (the distance between the centre of mass and the roll centre). This is based upon an estimated CoG height of 18" for a standard car.
A large roll couple - therefore a low roll centre - will transfer the loads more through 'soft' items (springs and dampers) and a lower roll couple (a high roll centre) will do it more through the length of the solid suspension components / lower arm. The same comes about when the roll couple either acts in the same direction as cornering force, or the opposite, due to roll centre migration in the horizontal direction. You can then imagine that lower roll centres (and ones which have migrated in the opposite direction to cornering loads) make the car feel 'squishy' in body roll, and high roll centres (and those migrated in the same direction) make it feel 'snappy'.
Camber correction: When the car rolls over, the ideal is that both tyres are kept upright (or at least as close as possible to the static camber value). Double wishbone systems are better than Mac Struts at doing this (when designed half-right!).
A note: There is some real weirdness going on with the rear roll centre after the car has been lowered around 20-25mm or more (when using my measurements - therefore it is possible due to measuring errors that this tipping point could be 35mm, for example, especially if toyota themselves offer a kit which lowers the car 30mm). At this point the roll centre location actually reverses the direction in which it migrates compared with standard ride height during body roll (in both X and Y directions) - this will absolutely explain 'snappy' rear ends.
The diverging roll centre migration front to rear in both X and Y planes at standard ride heights (and maybe down to -30mm ish, depending on accuracy of my measurements as explained above) may explain why our cars seem to benefit so much from chassis bracing. Each end is trying to do something quite different, so stiffening the chassis will be felt drastically.
So here we go:
MR2Height.jpg
The links for the suspension setups are as follows...
Standard ride height:
http://vsusp.com/#0.8%26project_name%3Adefault%20values%26trim%7Bbody_roll_angle%3A0%7Cfront.left_bump%3A0%7Crear.left_bump%3A0%7Cfront.right_bump%3A0%7Crear.right_bump%3A0%7D%26front%7Bframe.susp_type%3A1%7Cframe.bottom_y%3A15600%7Cframe.center_to_upper_mount_x%3A54700%7Cframe.bottom_to_upper_mount_y%3A58000%7Cframe.center_to_lower_mount_x%3A36200%7Cframe.bottom_to_lower_mount_y%3A2800%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A33900%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A7000%7Cknuckles.hub_to_lower_y%3A10000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A19500%7Cknuckles.strut_incl%3A8700%7Csteering.active%3A1%7Csteering.hub_to_outer_tie_rod_x%3A6500%7Csteering.hub_to_outer_tie_rod_y%3A6000%7Cwheels.offset%3A4500%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A18500%7Ctires.aspect_ratio%3A5500%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26rear%7Bframe.susp_type%3A1%7Cframe.bottom_y%3A16800%7Cframe.center_to_upper_mount_x%3A48000%7Cframe.bottom_to_upper_mount_y%3A63000%7Cframe.center_to_lower_mount_x%3A30400%7Cframe.bottom_to_lower_mount_y%3A2500%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A37800%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A9000%7Cknuckles.hub_to_lower_y%3A10000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A17000%7Cknuckles.strut_incl%3A7800%7Csteering.active%3A0%7Csteering.hub_to_outer_tie_rod_x%3A7620%7Csteering.hub_to_outer_tie_rod_y%3A7620%7Cwheels.offset%3A4500%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A20500%7Ctires.aspect_ratio%3A5000%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26pref%7Bdiag1.px_per_mm%3A300%7Cdiag1.front_or_rear%3Afront%7Ctab.active%3A0%7Cunits%3A1%7Cshow.f%3A1%7Cshow.ca%3A1%7Cshow.k%3A1%7Cshow.st%3A1%7Cshow.stl%3A1%7Cshow.w%3A1%7Cshow.t%3A1%7Cshow.rc%3A1%7Cshow.rcl%3A1%7Cshow.ic%3A1%7Cshow.icl%3A1%7Cshow.fvsa%3A0%7Cshow.tl%3A0%7Cshow.kpil%3A0%7Credraw_during_drag%3A1%7Cchart.x_axis_center%3A0%7Cchart.x_axis_window%3A10%7Cchart.x_axis_num_steps%3A21%7Cchart.x_axis_field%3Atrim.body_roll_angle%7Cchart.y_axis_fields%3A%5BFR%5D.tires.left_camber%7D
30mm lowered (eg. lowering springs):
http://vsusp.com/#0.8%26project_name%3Adefault%20values%26trim%7Bbody_roll_angle%3A0%7Cfront.left_bump%3A0%7Crear.left_bump%3A0%7Cfront.right_bump%3A0%7Crear.right_bump%3A0%7D%26front%7Bframe.susp_type%3A1%7Cframe.bottom_y%3A12600%7Cframe.center_to_upper_mount_x%3A54700%7Cframe.bottom_to_upper_mount_y%3A58000%7Cframe.center_to_lower_mount_x%3A36200%7Cframe.bottom_to_lower_mount_y%3A2800%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A33900%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A7000%7Cknuckles.hub_to_lower_y%3A10000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A19500%7Cknuckles.strut_incl%3A8700%7Csteering.active%3A1%7Csteering.hub_to_outer_tie_rod_x%3A6500%7Csteering.hub_to_outer_tie_rod_y%3A6000%7Cwheels.offset%3A4500%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A18500%7Ctires.aspect_ratio%3A5500%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26rear%7Bframe.susp_type%3A1%7Cframe.bottom_y%3A13800%7Cframe.center_to_upper_mount_x%3A48000%7Cframe.bottom_to_upper_mount_y%3A63000%7Cframe.center_to_lower_mount_x%3A30400%7Cframe.bottom_to_lower_mount_y%3A2500%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A37800%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A9000%7Cknuckles.hub_to_lower_y%3A10000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A17000%7Cknuckles.strut_incl%3A7800%7Csteering.active%3A0%7Csteering.hub_to_outer_tie_rod_x%3A7620%7Csteering.hub_to_outer_tie_rod_y%3A7620%7Cwheels.offset%3A4500%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A20500%7Ctires.aspect_ratio%3A5000%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26pref%7Bdiag1.px_per_mm%3A300%7Cdiag1.front_or_rear%3Afront%7Ctab.active%3A0%7Cunits%3A1%7Cshow.f%3A1%7Cshow.ca%3A1%7Cshow.k%3A1%7Cshow.st%3A1%7Cshow.stl%3A1%7Cshow.w%3A1%7Cshow.t%3A1%7Cshow.rc%3A1%7Cshow.rcl%3A1%7Cshow.ic%3A1%7Cshow.icl%3A1%7Cshow.fvsa%3A0%7Cshow.tl%3A0%7Cshow.kpil%3A0%7Credraw_during_drag%3A1%7Cchart.x_axis_center%3A0%7Cchart.x_axis_window%3A10%7Cchart.x_axis_num_steps%3A21%7Cchart.x_axis_field%3Atrim.body_roll_angle%7Cchart.y_axis_fields%3A%5BFR%5D.tires.left_camber%7D
50mm lowered (figure a lot of track cars on coilovers would go about here):
http://vsusp.com/#0.8%26project_name%3Adefault%20values%26trim%7Bbody_roll_angle%3A0%7Cfront.left_bump%3A0%7Crear.left_bump%3A0%7Cfront.right_bump%3A0%7Crear.right_bump%3A0%7D%26front%7Bframe.susp_type%3A1%7Cframe.bottom_y%3A10600%7Cframe.center_to_upper_mount_x%3A54700%7Cframe.bottom_to_upper_mount_y%3A58000%7Cframe.center_to_lower_mount_x%3A36200%7Cframe.bottom_to_lower_mount_y%3A2800%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A33900%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A7000%7Cknuckles.hub_to_lower_y%3A10000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A19500%7Cknuckles.strut_incl%3A8700%7Csteering.active%3A1%7Csteering.hub_to_outer_tie_rod_x%3A6500%7Csteering.hub_to_outer_tie_rod_y%3A6000%7Cwheels.offset%3A4500%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A18500%7Ctires.aspect_ratio%3A5500%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26rear%7Bframe.susp_type%3A1%7Cframe.bottom_y%3A11800%7Cframe.center_to_upper_mount_x%3A48000%7Cframe.bottom_to_upper_mount_y%3A63000%7Cframe.center_to_lower_mount_x%3A30400%7Cframe.bottom_to_lower_mount_y%3A2500%7Ccontrol_arms.upper_length%3A24800%7Ccontrol_arms.lower_length%3A37800%7Cknuckles.hub_to_upper_x%3A15000%7Cknuckles.hub_to_lower_x%3A9000%7Cknuckles.hub_to_lower_y%3A10000%7Cknuckles.hub_to_upper_y%3A13000%7Cknuckles.hub_to_strut_axis%3A17000%7Cknuckles.strut_incl%3A7800%7Csteering.active%3A0%7Csteering.hub_to_outer_tie_rod_x%3A7620%7Csteering.hub_to_outer_tie_rod_y%3A7620%7Cwheels.offset%3A4500%7Cwheels.diameter%3A1500%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A20500%7Ctires.aspect_ratio%3A5000%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7620%7Ctires.compression%3A0%7D%26pref%7Bdiag1.px_per_mm%3A300%7Cdiag1.front_or_rear%3Afront%7Ctab.active%3A0%7Cunits%3A1%7Cshow.f%3A1%7Cshow.ca%3A1%7Cshow.k%3A1%7Cshow.st%3A1%7Cshow.stl%3A1%7Cshow.w%3A1%7Cshow.t%3A1%7Cshow.rc%3A1%7Cshow.rcl%3A1%7Cshow.ic%3A1%7Cshow.icl%3A1%7Cshow.fvsa%3A0%7Cshow.tl%3A0%7Cshow.kpil%3A0%7Credraw_during_drag%3A1%7Cchart.x_axis_center%3A0%7Cchart.x_axis_window%3A10%7Cchart.x_axis_num_steps%3A21%7Cchart.x_axis_field%3Atrim.body_roll_angle%7Cchart.y_axis_fields%3A%5BFR%5D.tires.left_camber%7D
And for comparison here is a double wishbone setup I designed for a single seater, based around a Mk1 Miata, which I never got round to building sadly:
http://vsusp.com/?tool=2d#0.8%26project_name%3AMXR1%26trim%7Bbody_roll_angle%3A0%7Cfront.left_bump%3A0%7Crear.left_bump%3A0%7Cfront.right_bump%3A0%7Crear.right_bump%3A0%7D%26front%7Bframe.susp_type%3A0%7Cframe.bottom_y%3A8500%7Cframe.center_to_upper_mount_x%3A38100%7Cframe.bottom_to_upper_mount_y%3A27000%7Cframe.center_to_lower_mount_x%3A32892%7Cframe.bottom_to_lower_mount_y%3A7800%7Ccontrol_arms.upper_length%3A17300%7Ccontrol_arms.lower_length%3A28000%7Cknuckles.hub_to_upper_x%3A12776%7Cknuckles.hub_to_lower_x%3A7745%7Cknuckles.hub_to_lower_y%3A8559%7Cknuckles.hub_to_upper_y%3A12344%7Cknuckles.hub_to_strut_axis%3A14000%7Cknuckles.strut_incl%3A8000%7Cwheels.offset%3A3500%7Cwheels.diameter%3A1300%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A18500%7Ctires.aspect_ratio%3A6000%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7600%7Ctires.compression%3A0%7D%26rear%7Bframe.susp_type%3A0%7Cframe.bottom_y%3A10500%7Cframe.center_to_upper_mount_x%3A39000%7Cframe.bottom_to_upper_mount_y%3A25200%7Cframe.center_to_lower_mount_x%3A26000%7Cframe.bottom_to_lower_mount_y%3A5900%7Ccontrol_arms.upper_length%3A19500%7Ccontrol_arms.lower_length%3A36500%7Cknuckles.hub_to_upper_x%3A15391%7Cknuckles.hub_to_lower_x%3A11907%7Cknuckles.hub_to_lower_y%3A9525%7Cknuckles.hub_to_upper_y%3A12065%7Cknuckles.hub_to_strut_axis%3A14000%7Cknuckles.strut_incl%3A8000%7Cwheels.offset%3A3500%7Cwheels.diameter%3A1300%7Cwheels.diameter_expl%3A35000%7Ctires.size_convention%3A0%7Ctires.section_width%3A18500%7Ctires.aspect_ratio%3A6000%7Ctires.diameter_expl%3A50000%7Ctires.width_expl%3A7600%7Ctires.compression%3A0%7D%26pref%7Bdiag1.px_per_mm%3A200%7Cdiag1.front_or_rear%3Afront%7Ctab.active%3A0%7Cunits%3A1%7Cshow.f%3A1%7Cshow.ca%3A1%7Cshow.k%3A1%7Cshow.w%3A1%7Cshow.t%3A1%7Cshow.rc%3A1%7Cshow.ic%3A1%7Cshow.fvsa%3A0%7Cshow.tl%3A0%7Cshow.kpil%3A0%7Credraw_during_drag%3A1%7Cchart.x_axis_center%3A0%7Cchart.x_axis_window%3A5%7Cchart.x_axis_num_steps%3A21%7Cchart.x_axis_field%3Atrim.body_roll_angle%7Cchart.y_axis_fields%3A%5BFR%5D.general.roll_center.y%7D]MXR1
Have a play with wiggling the wheels round and you will see there is very little roll centre migration, plus good camber correction under both bump and roll.
Will have to leave this until tomorrow - had a couple of beers and it's wine o-clock now!!
Thanks Adam, much obliged. Playing with it and as much confirmed as stunned.
Guys, what I now don't understand at all are the dogbones. As far as I understood after playing with the settings for the lowered car from above, they seem to make things even worse.
The subframe should be lifted, not lowered.
Do I miss something ?
BR
Ralf
Quote from: ralf321 on October 29, 2020, 20:06Guys, what I now don't understand at all are the dogbones. As far as I understood after playing with the settings for the lowered car from above, they seem to make things even worse.
The subframe should be lifted, not lowered.
Do I miss something ?
BR
Ralf
Thát
THE question Ralf.
Point is that the front roll centre lowers too.
Hence my thinking that they tried restore a bit of the balance. Meaning that with RC ball joints they should come out?
Quote from: ralf321 on October 29, 2020, 20:06Guys, what I now don't understand at all are the dogbones. As far as I understood after playing with the settings for the lowered car from above, they seem to make things even worse.
The subframe should be lifted, not lowered.
Do I miss something ?
BR
Ralf
That is correct sir. Im happy that Boris is making them for whom ever wants to tune or try them out and this is not about harming his sales for them but they do exactly the opposite of what you want and will make things worse especially if you want to lower the car further.
Quote from: Petrus on October 29, 2020, 20:22Quote from: ralf321 on October 29, 2020, 20:06Guys, what I now don't understand at all are the dogbones. As far as I understood after playing with the settings for the lowered car from above, they seem to make things even worse.
The subframe should be lifted, not lowered.
Do I miss something ?
BR
Ralf
Thát THE question Ralf.
Point is that the front roll centre lowers too.
Hence my thinking that they tried restore a bit of the balance. Meaning that with RC ball joints they should come out?
I think you actually may have solved the reason for the dog bones. It is because they were designed for the TRD Sportivo kit as a whole. Its possible that the fronts were designed with a particular amount of lowering or the rear needed to be higher for clearance which could be due to all kinds of reasons possibly regulations, looks or because the supplier for the springs and dampers could not get the right size and therefore the rear roll center had to be lowered to match the front. Toyota is quiet conservative trying to make everything safe for road use.
This is why you shouldn't use the dog bones as a separate item without considering the entire kit or what you want to do with the car as far as a radical set up but I cant see a scenario where they are beneficial for anything but the kit. If you buy a different system there shouldn't have any benefit with the dog bones and there is a good argument to be made that it will make it worse not being able to preserve the roll center.
if you have a set of coil overs you can set the ride height and do essentially the same thing.
Double post.
Quote from: Dev on October 30, 2020, 17:28I cant see a scenario where they are beneficial for anything but the kit.
They are to correct the effect of the front being lowered more than the rear i.e. the respective roll centres. It is ´roll centre tuning´. As such they are beneficial for any modification resulting in rake.
Quote from: Dev on October 30, 2020, 17:28I think you actually may have solved the reason for the dog bones.
Was reflecting on that.
Kinda cool no?!
Almost 20 years later, a Dutchman confined by Covid19 in the Andalucian mountains solves the dog bones enigma.
:-)
Quote from: Petrus on October 31, 2020, 01:06Quote from: Dev on October 30, 2020, 17:28I think you actually may have solved the reason for the dog bones.
Was reflecting on that.
Kinda cool no?!
Almost 20 years later, a Dutchman confined by Covid19 in the Andalucian mountains solves the dog bones enigma.
:-)
Oh Dev his head is big enough already.
Thats why he needs a drop top wouldn't fit in a coupe.
Quote from: 1979scotte on October 31, 2020, 07:24Quote from: Petrus on October 31, 2020, 01:06Quote from: Dev on October 30, 2020, 17:28I think you actually may have solved the reason for the dog bones.
Was reflecting on that.
Kinda cool no?!
Almost 20 years later, a Dutchman confined by Covid19 in the Andalucian mountains solves the dog bones enigma.
:-)
Oh Dev his head is big enough already.
Thats why he needs a drop top wouldn't fit in a coupe.
Sometimes flattery followed by a plausible assertion is the best way to have someone see the same reality.
For many years some were adding the dog bones under the impression they fixed the roll center for other setups other then the TRD until someone wise enough went against popular opinion. On car forums its easy for everyone to get lulled into misguided concepts especially when they complicate the math to appear that its rooted in some kind of academic wizardry but its usually the simplest and most obvious explanation that is usually correct.
Added numbers for my car (incl. driver and half tank of gas) with the Sportivo set in the formula for the natural suspension frequency and arrive at:
1.42 Hz. front and 1.85 Hz. rear (130%)
from OEM (on my lighter car)
1.23 and 1.46 (118%)
OEM weight
1.10 and 1.38 (125%)
The Whitelines are under.
Stiff setting up front, soft rear; equivalent to the Sportivo bars.
Did a short test run on moist to wet roads in a chilly drizzle. In one word; confidence inspiring!
I am very content with how the car handles now, véry.
I máy go a hole stiffer at one side at rear but then... maybe not.
You should take it somewhere safe like an open parking lot so that you can take it to the limit to see how it behaves at normal speeds and then tune to where it's safe. I tuned my Whitline to where it will oversteer with enough warning to recover.
Started with the ´safe´ TRD very mild initial understeer as before and will take it from there. I will need to factor in the increased rear traction from about 50/60 km/h.
Sofar roads are ccccold and not dry.
At the coast now. Will go back over the mountain roads.
Will take my time to xperience the set up.
This afternoon set the rear bars one hole stiffer; the second hole, that is 25% stiffer than the softest hole.
If that prooves too much, I can go one hole softer at one side only, halving the step. And hey, can be that I like the softest best 8)
Few things illustrate as clearly that a car is a single complex system as sway bars do: Change the rear bar and it affects the front ;D
Übercool I think.
Quote from: Petrus on December 23, 2020, 10:19Few things illustrate as clearly that a car is a single complex system as sway bars do: Change the rear bar and it affects the front ;D
Übercool I think.
It is but, its still a coarse way of adjusting a cars behavior and I would say the last best way to account for tires and driving style. The downside with going too aggressive with the settings is losing part of the independent suspension when the sway bars are tested at the limits on less than ideal road conditions.
Striking a balance is important. Fortunately you have a properly researched set of dampers which will keep the swaybar adjustment consistent. Also keep in mind that the demands of the tires have gone up tremendously since its being pushed to the edge of traction earlier. You might not notice this so much in the dry but it becomes very apparent in the wet.
Quote from: Dev on December 24, 2020, 14:39It is but, its still a coarse way of adjusting a cars behavior
I´d say fine tuning the traction balance as part of the overall set up.
You need the correct springs for ride hight, the suspension frequency and balance of it all with de damping to match the springs and use. The sway bars are a finishing touch to the traction balance.
That observed, for them to have effect they must be strong/stiff enough relative to the spring rate (which will increase the frequency), just not so strong to noticeably up the spring rate. Bit of a catch that.
Good thing Toyota set the bar ;-) at the right hight with the Sportivo bars.
I have only gone one notch up at the rear. Remember my car is a good deal lightened which affects things a bit. P.e. the suspension frequency is higher but the effect of sway bars less because there is less roll to counteract. Etc.
As you may have read, first impressions were on wet roads. Since then changing conditions reigned or is that rained?! ;-)
Do note that sway bars do NOT reduce the overall traction availeble. They just shiít part of it around.
If set up correctly they reduce the amount of traction loss to tyre load sensitivity due to roll, weight transfer, i.e. relatively incréase availeble traction.
Today splendidly sunny. Not going to push the envelope though; going for X-mas diner with Antequera gf and her kids.
p.s. The car drives só nicely and well balanced now, I could NOT resist nailing it through just a few corners and over a handful of roundabouts. I loved it as it came in OEM guise and lóve it now :-)