Rear of car weaves under heavy acceleration - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

nighttowl · 05-18-2014, 08:54 PM

the short story - the back of the car slightly weaves back and forth under heavy acceleration in second gear without wheel spin (at least as far as I know). the car has BMR upper control and trailing arms, along with full poly suspension kit sway bars are an adjustable LSR set.

I recently upgraded my wheels and tires, 275's on the front, 315's on the rear. this was not apparent until I swapped on the new wheels. I know the wider tires are tracking irregularities in the pavement, it is apparent under normal driving.

I first thought something was loose, but I double checked all the bolts just now, and they are all tight.

I'm wondering if the rear differential with the wider rear tires is letting one wheel spin, and possibly the spinning tire is moving from left to right and back causing the weaving.

has anyone had a similar issue?

GFORCE1320 · 05-19-2014, 12:28 PM

Did you get aligned after doing the suspension work? It's real important to get a good alignment after disturbing control arms.

Trob85 · 05-19-2014, 02:21 PM

Did you put cradle and diff bushings in I had that problem did the swap not another issue.

axis · 05-19-2014, 03:07 PM

Check the upper control arm bushing. The vertical one.

nighttowl · 05-19-2014, 04:43 PM

The car was aligned afterwards.
the cradle bushings were changed, but I did not do the diff bushings.

the control arm bushings looked ok when I installed the poly rear upper control arm bushings.

I was thinking about borrowing a gopro and stickng it to the car to see what is moving.

nighttowl · 05-19-2014, 10:25 PM

after thinking about it a bit and testing out my theory, I figured it out.
it is the traction control modulating the rear brakes that is making the car weave back and forth in second.

first gear is worthless above 3k, it just spins the tires even with traction control on. second starts to spin the tires above 4500 rpm without traction control on. with the 275's on the rear it would spin the tires with traction control on in second, which is why I never noticed it until I put the 315's on.

wakespeak · 05-27-2014, 12:12 PM

Mine weaves around also. I was thinking it was cradle bushings or the limited slip alternating side to side. This is with the traction control off usually. You have more power so you could be overpowering the brakes with TC on. Try it with the TC off and see if you get the same pattern.

Irnwkrkev · 05-27-2014, 01:41 PM

BMR had revised one of their bushings a couple of years ago as well, it was a hair too small. The one that goes in the rear hub/spindle. Think it's the LCA.

05-18-2014, 08:54 PM	#1
nighttowl Sarcasm loading -------- Drives: 2018 ZL1 1LE Join Date: Dec 2011 Location: TX Posts: 1,806 View My Garage	Rear of car weaves under heavy acceleration the short story - the back of the car slightly weaves back and forth under heavy acceleration in second gear without wheel spin (at least as far as I know). the car has BMR upper control and trailing arms, along with full poly suspension kit sway bars are an adjustable LSR set. I recently upgraded my wheels and tires, 275's on the front, 315's on the rear. this was not apparent until I swapped on the new wheels. I know the wider tires are tracking irregularities in the pavement, it is apparent under normal driving. I first thought something was loose, but I double checked all the bolts just now, and they are all tight. I'm wondering if the rear differential with the wider rear tires is letting one wheel spin, and possibly the spinning tire is moving from left to right and back causing the weaving. has anyone had a similar issue? __________________ "The salesman actually told me to stop getting it sideways during the test drive" 2018 MBM ZL1 1LE - Stock 2014 CRT ZL1 574 rwhp, 537 rwtq - SOLD 2010 IBM SS Camaro VVT L99 w/ TR6060 swap, 489 rwhp, 444 rwtq - SOLD

05-19-2014, 02:21 PM	#3
Trob85 Svt lol Drives: 2011 ss inferno orange blown Join Date: Jan 2012 Location: Topeka Posts: 2,312	Did you put cradle and diff bushings in I had that problem did the swap not another issue. __________________ plasti dip is not a mod.......and a cold air intake doesn't make you fast!

05-19-2014, 03:07 PM	#4
axis Search Ninja Drives: 2010 Black 2SS/RS A6 Join Date: Oct 2009 Location: Central Ark Posts: 7,183	Check the upper control arm bushing. The vertical one. __________________ 2010 Black 2SS/RS A6 Halltech CF 102 fed GPI modded intake manifold Bo (knows) White ported TB Kooks LT's/ Dynomax VT Pfadted (springs/sways) Dyno tuned by Rhino and GPI I once parallel parked a train.

05-19-2014, 04:43 PM	#5
nighttowl Sarcasm loading -------- Drives: 2018 ZL1 1LE Join Date: Dec 2011 Location: TX Posts: 1,806 View My Garage	The car was aligned afterwards. the cradle bushings were changed, but I did not do the diff bushings. the control arm bushings looked ok when I installed the poly rear upper control arm bushings. I was thinking about borrowing a gopro and stickng it to the car to see what is moving. __________________ "The salesman actually told me to stop getting it sideways during the test drive" 2018 MBM ZL1 1LE - Stock 2014 CRT ZL1 574 rwhp, 537 rwtq - SOLD 2010 IBM SS Camaro VVT L99 w/ TR6060 swap, 489 rwhp, 444 rwtq - SOLD

05-19-2014, 10:25 PM	#6
nighttowl Sarcasm loading -------- Drives: 2018 ZL1 1LE Join Date: Dec 2011 Location: TX Posts: 1,806 View My Garage	after thinking about it a bit and testing out my theory, I figured it out. it is the traction control modulating the rear brakes that is making the car weave back and forth in second. first gear is worthless above 3k, it just spins the tires even with traction control on. second starts to spin the tires above 4500 rpm without traction control on. with the 275's on the rear it would spin the tires with traction control on in second, which is why I never noticed it until I put the 315's on. __________________ "The salesman actually told me to stop getting it sideways during the test drive" 2018 MBM ZL1 1LE - Stock 2014 CRT ZL1 574 rwhp, 537 rwtq - SOLD 2010 IBM SS Camaro VVT L99 w/ TR6060 swap, 489 rwhp, 444 rwtq - SOLD

05-19-2014, 12:28 PM	#2
GFORCE1320 Drives: 05 GTO Join Date: Jul 2009 Location: Wichita, KS Posts: 1,243	Did you get aligned after doing the suspension work? It's real important to get a good alignment after disturbing control arms.

05-27-2014, 12:12 PM	#7
wakespeak Drives: 2020 ZL1 1LE Join Date: Sep 2012 Location: Austin, Texas Posts: 1,335	Mine weaves around also. I was thinking it was cradle bushings or the limited slip alternating side to side. This is with the traction control off usually. You have more power so you could be overpowering the brakes with TC on. Try it with the TC off and see if you get the same pattern.

05-27-2014, 01:41 PM	#8
Irnwkrkev Drives: 2011 SS/RS LS3 Join Date: Oct 2010 Location: Miami Posts: 528	BMR had revised one of their bushings a couple of years ago as well, it was a hair too small. The one that goes in the rear hub/spindle. Think it's the LCA.