Wobbling, bouncing around - high speed cornering

killrain · 08-03-2016, 03:56 PM

Updates?

zefaulter · 08-03-2016, 06:04 PM

Quote:

Originally Posted by killrain

Updates?

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 · 08-03-2016, 06:19 PM

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 · 08-04-2016, 10:43 AM

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.

zefaulter · 09-08-2016, 09:02 AM

Quote:

Originally Posted by 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.

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

zefaulter · 09-08-2016, 09:08 AM

This seems like a very common problem when you're lowered with stock struts. Scary stuff on the highway for sure

gbrettin · 09-08-2016, 10:05 AM

I had something similar happen to my car after RE-11's were mounted. I have Whiteline sways in the front and rear and both were set to the stiffest setting. When I tested my car on a long sweeping corner, after the RE-11's were installed, the rear of my car wouldn't settle and wobble.

The fix for me was to back out the stiffness on the sways all the way around the car.

gbrettin · 09-08-2016, 10:06 AM

Quote:

Originally Posted by 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

Ahhh, blown shock...

Glad you got it figured out!

zefaulter · 10-16-2016, 03:49 PM

please someone just come stab me in the ***.... car still doing it after new Koni yellow install, alignment, swaybar end links...**** me

08-04-2016, 10:43 AM	#49 (permalink)
B&W_Evader Track Member Join Date: Aug 2011 Location: CA Posts: 972 Drives: slower than before Rep Power: 387	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. zefaulter likes this. __________________ \|RIP\|6spd-sport\|OSG-LSD\|XP8\|RBF600\|Eibach Sways\|RE-71R\|FI-34Row\|Gen3-CAI\|Yaw P.S.\|

09-08-2016, 10:05 AM	#52 (permalink)
gbrettin A True Z Fanatic Join Date: Oct 2010 Location: Portage, MI Posts: 2,279 Drives: Tricycle Rep Power: 589151	I had something similar happen to my car after RE-11's were mounted. I have Whiteline sways in the front and rear and both were set to the stiffest setting. When I tested my car on a long sweeping corner, after the RE-11's were installed, the rear of my car wouldn't settle and wobble. The fix for me was to back out the stiffness on the sways all the way around the car. zefaulter likes this.

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08-03-2016, 03:56 PM	#46 (permalink)
killrain A True Z Fanatic Join Date: Feb 2016 Location: san antonio tx Posts: 1,433 Drives: 2013 370z sport Rep Power: 349779	Updates?

08-03-2016, 06:19 PM	#48 (permalink)
wanabgts Base Member Join Date: Nov 2015 Location: Portland Oregon Posts: 36 Drives: 09 370z Nismo Rep Power: 9	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.

09-08-2016, 09:08 AM	#51 (permalink)
zefaulter A True Z Fanatic Join Date: Jan 2013 Location: Toronto, Canada Posts: 1,983 Drives: 40th 370Z Rep Power: 27	This seems like a very common problem when you're lowered with stock struts. Scary stuff on the highway for sure

10-16-2016, 03:49 PM	#54 (permalink)
zefaulter A True Z Fanatic Join Date: Jan 2013 Location: Toronto, Canada Posts: 1,983 Drives: 40th 370Z Rep Power: 27	please someone just come stab me in the *.... car still doing it after new Koni yellow install, alignment, swaybar end links...** me