Wobbling, bouncing around - high speed cornering

batman_4

So was the problem fixed? I've been dealing with the same similar issue and haven't been able to solve it.

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'09 6spd. Touring: Eibach / SPC / Motordyne / Berk / Z1 / Oneighty / Mines / SSR / Stillen / CFE

zefaulter

Sway bar endlinks. So far so good.

kenchan

uhh... hope datz not ur garage flooring..

zefaulter

No, but I use it all the time. Soft and comfy to crawl under the car on

jchammond

You say alignment was good?
ck.what it was before you added the lowering parts/as you lower;it gives you more negative camber,
I don't have any lowering springs-but on alignment movement's;;;when you adjust the camber negative(top of tire lean inward)it will also move the rear toe negative(front of tire will point outwards)
Rear must have some Positive Toe or the Azz end will be dancing around;especially at higher speeds & hard acceleration or deceleration.
For a quick check before taking it in;measure the width on the front side & backside of rear tires (on a common tread groove)
Good to have a helper & be sure to stretch an even pull/as high as possible(3 or 4" from ground) without contacting underside of car.
wouldn't hurt to ck. the front also ;;;But Remember;the rear Toe Spec.call's for about twice the positive toe as the front.
On a level surface,you should have 1/8---1/4" closer gap on Front side of rear wheels.
Fuel level will affect this measurement.
Actual specs. for total Toe on rear are (min 0.079" Nominal 0.146" max 0.213")
I got mine set on the higher end w/stock ride height,,,car behave's well.
The rear camber & toe are adjustable on Stock ~Z~ w/the Factory eccentric bolt's.

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zefaulter

So it's not fixed

batman_4

.. no improvement at all???

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'09 6spd. Touring: Eibach / SPC / Motordyne / Berk / Z1 / Oneighty / Mines / SSR / Stillen / CFE

zefaulter

I thought it went away but I was wrong. Doing 80kph on a bumpy road felt unstable but 160 on a good road was fine. It might be the road plus the stiffer diff bushing. I'm out of ideas

zefaulter

Still does it

2011 Nismo#91

Remove the rear bar completely and see if the problem gets better worse. It's not really necessary a number of people that track their car find it's not too beneficial.

killrain

Updates?

zefaulter

Out of town for the week. Going to install FUCA and get realigned. I'll put the stock rear sways possibly at the same time just hate having to remove everything in the process

wanabgts

This is a problem with all of the cars IMO, my car had the same issue. Especially with the stock suspension. These cars have a TON of camber change throughout the suspension travel, which with low offset wheels or big tires etc can cause the rear to feel very unstable. The bumpsteer is actually pretty good for a car that has this much travel.

My track day car was scary with 315's until I got the suspension firm enough to limit the change to acceptable range. My car will go from negative 1.8* rear to +5* before I hit the limit of my downtravel.

When I put springs on my car and big front bar, the car was much more stable.

Zack

**edit****

I think have non-adjustable rear lower arms also is a problem, the longer arm length you will have with an adjustable arm when lowered would help greatly with geometry changes.

B&W_Evader

Couple more things to check on each tire...

Wheel Bearings: lift it off the ground and Push/Pull Top and Bottom (12 & 6 o-clock). Do it with gusto! There should be very little to no play. Less than 1/64 inch at the rim I would think is fine.

Control arms: Have someone else Push/Pull 3 & 9 o-clock. Watch the control arms. If you see the ends shift in their seats, replace them.

Shocks maybe?
How do your shocks feel? Does the car settle immediately after a large bump or does it take a 2 or 3 cycles to settle.

Also, I would expect a little instability over cobblestone type roads since we have fairly stiff suspensions. If you want better stability over that kind of surface go with the dual rate springs like swift.

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zefaulter

It's the rear shocks... I'll have to confirm but going over speed bump yesterday I went a little fast intentionally and the rear kept bouncing for a couple seconds