My e30 is thinking it's a VW!

[JJ1]

maybe it's too late and i'm missing something, but a bigger rear bar won't help motive traction for the rear. If that were the case fwd cars would run no rear bar and rwd cars would run a small front bar.

I never said it would, infact I said the opposite.

A big front bar will lift the front inside wheel to lift when rocketing out of a corner. Am i missing something here? Ps, i think sway setup should be used only to change the handling characteristics of the car. If it feels good and it's lifting a wheel, it's not 'horrible' in my book as long as there are not much other ill effects

I agree.

[Lof8]

I would bet those GC upper mounts have a lot to do with it.

Without those, you'd be drooping more and not see any lift. I doubt that the lift is a "bad" thing in that case.

[Jean]

M3 sway links dramatically improve turn in and responsiveness on any sway bar. Everyone should have these on their cars!

As far as lifting the inside rear tires, do you have poly bushings outback for the RTABs and subframe? Those will dramatically improve the responsiveness of the rear, and allow you to run a slightly softer rear spring rate.

That's odd that you're rear wheel is lifting lifting with no bar outback though...

I plan on giving the m3 links a try for the last two events this season, my strut housings have the tabs for them so need to get the right size links.

Car has new oem subframe/trailing arm bushings, but the upper mounts are the tall GC kind. So the trailing arms I imagine do not droop as much and may have to do with it as well. I can jack the car up and not worry about the rear springs falling out.

[e30polak]

Instead of using an Ireland bar would running existing bar but with m3 end links be just as effective?

M3 sway links dramatically improve turn in and responsiveness on any sway bar. Everyone should have these on their cars!

As far as lifting the inside rear tires, do you have poly bushings outback for the RTABs and subframe? Those will dramatically improve the responsiveness of the rear, and allow you to run a slightly softer rear spring rate.

That's odd that you're rear wheel is lifting lifting with no bar outback though...

[Jaxx_]

Alot of these guys run more rear bias and more rear spring or more rear sway bar. It gets the car to rotate better but the over sprung rear will cause FRONT inside wheel to lift.

maybe it's too late and i'm missing something, but a bigger rear bar won't help motive traction for the rear. If that were the case fwd cars would run no rear bar and rwd cars would run a small front bar. A big front bar will lift the front inside wheel to lift when rocketing out of a corner. Am i missing something here? Ps, i think sway setup should be used only to change the handling characteristics of the car. If it feels good and it's lifting a wheel, it's not 'horrible' in my book as long as there are not much other ill effects.

[Holland]

Wow, extremely interesting! I'm kinda sad to see this discussion end so soon, as it really spiked my interest.

[Wanganstyle]

Yeah, people modify the Subaru to stupid big rear bar and overly slammed front suspension and end Up loosing all the droop travel and inducing ridiculous bump steer

[JJ1]

I see what your saying about the center diff, but even if it was 100% front wheel drive when you step on the throttle weight transfers to the back regardless of what wheels have the power going to them. On an AWD car (STI) people who road race there cars want it to rotate better. Alot of these guys run more rear bias and more rear spring or more rear sway bar. It gets the car to rotate better but the over sprung rear will cause FRONT inside wheel to lift. Most people dont realize stiffer springs equal LESS traction as a rule, but stiffer suspension makes a car easier to drive and recover slides (much more forgiving). It also may allow you to run more aggressive tire fitment without rubbing which gives you more traction.

[Wanganstyle]

Yes, was 1995 sti-ra with rear 65% drive bias center diff and clutch rear;

It seemed to me that with the clutch rear vs viscous car would lift front inside tire more often on wot on steep high g cornering. Perhaps the diff change just gave me more traction to transfer mote weight??

Car had matched street spec medium size sway bars front and rear and would lift front inside tire on power sometimes.

[JJ1]

1) rear inside wheel lift is different than both inside wheels lifting. If both wheels are lifting during lateral load than you have to examine your spring rate (too stiff), your center of gravity (too high), and/or your roll center (too low).

2)

what would happen if:

1. rear spring rate was lowered
2. add rear bar

Adding or stiffening a swaybar is just like increasing spring rate. The only two reasons to have a swaybar are 1.ease of adjustment (if you have an adjustable swaybar) 2.ride comfort (because it only stiffens suspension if only one side is being compressed)

3)

how would adding more front sway bar stiffness reduce rear tire lift under braking?

answer:

Mine did the same. All the weight in the front compresses the front outside spring, not enough weight to compress the outside rear, so inside rear comes up. Needs a fat front sway bar, unfortunatley that equals understeer.

4)

I have lifted front inside tire cornering before on heavy spring rates but with rear bar, this was on an AWD car with rear bias and a tight set rear diff, for some reason the weaker locking diff would not lift as much front tire. Perhaps I just transferred more weight to rear?

again this has NOTHING to do with your diff. Its the reverse of Jeans problem you had a big rear bar and had inside front wheel lift under acceleration. Probably had an STI.

[Wanganstyle]

I assumed so. I dont think its possible to induce inside rear wheel lift under acceleration.

I didn't think so either but I have seen photos of gymkhana cars (evo or sti I think) lift 2 wheels while turning (one side of the car). I don't know how that works. I will see if can find some photos of this-

also have seen them accelerating and lifting rear wheel @ same time:

http://www.youtube.com/watch?v=9e2f5N3lNyE&feature=related

sorry for the strange questions, I'm interested to know of how different e30's are setup footwork wise; I have not autox'ed seriously since 2003.

what would happen if:

1. rear spring rate was lowered
2. add rear bar

compared to:

adding larger front bar and leaving rear no sway bar?

I do not understand the remove front or rear or both sway bar phenomenon, seems done in these cars more than others? Or is this an autoX thing? I have heard of civic's removing front or rear bar for autoX reasons.


how would adding more front sway bar stiffness reduce rear tire lift under braking?



would the rear still be jacking up on braking?

is this rear tire lift caused by the front braking force and turning to send all the weight to one side (like how full suspension mountain bikes can have strange rear tire hopping issues under braking)

I have lifted front inside tire cornering before on heavy spring rates but with rear bar, this was on an AWD car with rear bias and a tight set rear diff, for some reason the weaker locking diff would not lift as much front tire. Perhaps I just transferred more weight to rear?

[JJ1]

I assumed so. I dont think its possible to induce inside rear wheel lift under acceleration.

[Jean]

For what it's worth, pics 5345 5184 are with the car slowing down / on the brakes.

[JJ1]

yes, its not ideal for any reason to lift a wheel, but If the car had an open diff or less aggressive setting I don't think it would be as prone to lifting rear wheel on power.

lift has nothing to do with the diff

the car also has no rear sway bar, so the rear of the car is rolling more than normal - with the higher rate rear spring than front transferring the weight

the reason the wheel is lifting is because the suspension is not compressing on the outside wheel. It is TOO stiff already, so the weight of the car is not compressing the spring. But because of the lateral load being transferred and the suspension not working (that is compressing and rebounding, in this case compressing) the inside wheel comes up because the outside wheel cant compress. Imagine if you had two 20lb cars. One with very soft suspension and one fixed with no suspension. If you pushed the left side of the soft car it would sway to the right. If you pushed the left side of the fixed suspension car it would just roll over on its side.

does that make sense?

[Wanganstyle]

sorry, I did not specify more clearly;

yes, its not ideal for any reason to lift a wheel, but If the car had an open diff or less aggressive setting I don't think it would be as prone to lifting rear wheel on power.

the car also has no rear sway bar, so the rear of the car is rolling more than normal - with the higher rate rear spring than front transferring the weight

--wouldn't the addition of ANY rear sway bar reduce the sway of the rear end of car?

I'm guessing it may cause oversteer because of the high rear spring rate; but does not a sway bar "reduce sway" or keep the body tensioned against itself while cornering?

I have never (personally) lifted a rear wheel in a RWD car before while on power or trail braking for more than a split second on bumpy stuff-