Sway bars, anti roll bars

[Petrus]

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.

[moca2cv]

I'm soon to fit some Whitelines... would the general consensus be to go full soft to start and work your way up?

[tatieu]

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.

[tets]

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.

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!

[Petrus]

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.

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.

[AdamR28]

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.

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.

[Petrus]

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.

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.

[AdamR28]

I know.

real word road conditions using stock size summer street rubber.

This is important though...

[Petrus]

I know.

real 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.

[tets]

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

[AdamR28]

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!

[1979scotte]

I know.

real word road conditions using stock size summer street rubber.

This is important though...

His real world conditions are nothing like mine

[Petrus]

http://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.

[Petrus]

i've bought the bar to make the dog bones.

Snelbaard has them in stock ready made on my request.

[tets]

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!

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!

[Petrus]

His 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.

[AdamR28]

no 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.

[Petrus]

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

Thanks.
Wáy easier to digest for me than Milliken.

[tets]

no 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

[Petrus]

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!

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.

[tets]

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

[Petrus]

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 

[AdamR28]

common internet myth

Fixed that for you

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 )

[Petrus]

Apologies for filling the thread with slightly tangential stuff -

Aplogies accepted, please go on :-)

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.

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.

[tets]

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