[arpad_m]

Originally Posted by Z OH 6

The BMR rear cradle lock out will help and you won't notice any NVH compared to the solid bushings in the 1LE. You get 85-90% of the performance of the solid bushings without sacrificing NVH.

Spot on. I have these lockout bushings with a perfect alignment, and in a straight line the car just goes with little to no rear end drama.

[BlueinTN]

Originally Posted by bjzq8

I have a 2019 ZL1 auto that has the squirrely-ness problem. The previous owner attempted to fix it by replacing the tires with Nittos all around, but it is still very scary to drive. I had it aligned by a guy who has done race alignments for almost 40 years, and he said he'd never seen a car behave that way in his life, and he's seen a lot. He aligned it to what he thought would help but it is still a dangerous car, even at part throttle. He owns a 427-powered 69 Camaro and he said my ZL1 is the only car he's ever really been afraid of.

I looked over some of the forum posts about this and they all appear to be from 2018 or similar-aged...the only answer I could really get out of it was to replace the rear bushings with solids.

My question is, has anyone else fixed their ZL1's squirrely-ness with something other than bushings or alignment? I'm at a loss as to what could be causing such a terrible condition.

Tries.


Those are DOT drag radials? 100 TW.


I bet there rock hard and Nitto are junk in my opinion.


I would look over the forums and get a nice 200 treadwear name brand tire and try that.


Also double check they are the stock size. sizing can mess with the traction control make it come on way late when your al ready tank slapping.

[Z OH 6]

Originally Posted by BlueinTN

Tries.


Those are DOT drag radials? 100 TW.


I bet there rock hard and Nitto are junk in my opinion.


I would look over the forums and get a nice 200 treadwear name brand tire and try that.


Also double check they are the stock size. sizing can mess with the traction control make it come on way late when your al ready tank slapping.

Not all Nitto's are junk, their drag radials are very good.

[BlueinTN]

Originally Posted by Z OH 6

Not all Nitto's are junk, their drag radials are very good.

Sorry I should probably edit that out.

[Dabjbr]

I installed the ZLE solid subframe bushings. It is work no question. Definitely improved the feel and I don’t really notice any increased NVH.

Suggestions…
Post alignment specs so we can provide feedback.
Find a local ZL1 or SLE owner and have them drive and compare the feel.
Maybe try out their rear OE SC3 tires to see if it helps. They’re awesome when warm.

If it turns out your alignment is good and this issue is something larger than just bushings, you might have a failing suspension arm/joint that is throwing toe off under acceleration.

[Gunkk]

I agree with the above on getting a 2nd opinion ... particularly while driving a car in January in Illinois. Traction will be garbage as the tires will be hard as hockey pucks.

Originally Posted by clg82

^^This, did the whole swap in my garage on jack stands. Completely changed the way the rear felt under load at high speeds.

How did you (re?)clock the bushings on jack stands? Did you set it on blocks or could you reach all the bolts with the car on the ground? Or can you do the job without having to touch the clocked rubber ones?

[CalgaryZL1]

Originally Posted by bjzq8

Currently it has Nitto NT555G2s on it. All four tires are at 32psi, but I've tried everything from 26 to 40, and variations on the front and back both ways. I don't know what he aligned it to, but he said the rear toe was off quite a bit. He tried changing the alignment several times over the span of a week and nothing seemed to help the condition. If it's breaking loose it's doing so at less than 1/4 throttle. Usually when I pull out to pass someone is when it presents itself most severely; as soon as I put my foot down (less than 1/4 throttle even) it acts like the rear end is very loose. He noted the same condition and suspected maybe it was something with the electronic differential, but to my knowledge, there's no way to fix that, is there? I have tried driving with all of the electronic gewgaws on and with them off; I've tried it in every drive mode and it's just the same.

I'm willing to put new stuff on the back end if it will fix it...can you tell me exactly the BMR parts you put on it?

Thanks for everyone's input! This is definitely the best car I've ever owned, but with one little flaw that might kill me!

Something is definitely not right, if both you and previous owner have been chasing this problem and having issues at quarter throttle.

[HemiDave]

Those tires are your problem IMO.

It's a 300 treadwear street tire that cant hold Scat Pack power, let alone ZL1 power.

[CalgaryZL1]

Originally Posted by HemiDave

Those tires are your problem IMO.

It's a 300 tread wear street tire that cant hold Scat Pack power, let alone ZL1 power.

It sounds like this was a problem even with the factory tires and this current tire selection was one of the changes to try and rectify the problem which obviously didn’t work, and possibly made the problem worse. To me, it is starting to sound like some unequal balanced power transfer to the wheels, quite possibly the rear end doing something weird

[HemiDave]

Originally Posted by CalgaryZL1

It sounds like this was a problem even with the factory tires and this current tire selection was one of the changes to try and rectify the problem which obviously didn’t work, and possibly made the problem worse. To me, it is starting to sound like some unequal balanced power transfer to the wheels, quite possibly the rear end doing something weird

Got you.
Then it may not be tire related as you said.

[BlueinTN]

Originally Posted by BlueinTN

Tries.


Those are DOT drag radials? 100 TW.


I bet there rock hard and Nitto are junk in my opinion.


I would look over the forums and get a nice 200 treadwear name brand tire and try that.


Also double check they are the stock size. sizing can mess with the traction control make it come on way late when your al ready tank slapping.

Sorry when I cut and pasted the tire it came back as the DOT drag radial version.


The second look there 320 TW list.




End point change out tires before re engineering the entire rear end of the car. Ted Jennety had a great long post about this a few years ago.

[Mark R]

There was also a dealer installed download that was supposed to help the diff lock up better.

[2023ZL1]

DRAG MODE MAKES A NOTICEABLE DIFFERENCE FOR THE BURNOUT IN POWER AND AND MAKES IT A MUCH MORE EVEN BURNOUT / LAUNCH BY MAKING SURE POWER IS PUT DOWN 50/50 LEFT TO RIGHT. I'M HAVING THE BMR CRADLE LOCK OUT DONE SOON AND UNTIL THEN I WONT EVEN TRY TO ROLL RACE ON THE STREET OR FLOOR IT BECAUSE IT SWAYS BACK AND FORTH. I'M NOT GOING TO SAY IT'S THE TIRES ALONE BUT MORE SO THE LACK OF CRADLE STIFFNESS AND REINFORCEMENT TO THE CHASSIS. I'VE DRAG RACED AT THE STRIP WITH MY MICHELINS WITHOUT DRAG MODE AND IT HAS NOT DONE THE SIDE TO SIDE CRAP, I'VE ALSO RACED ON THE MY ET STREET SS'S WITH DRAG MODE INITIATED AND IT DEAD HOOKS AND GOES STRAIGHT, NO SIDE TO SIDE MOVEMENT AT ALL. I DON'T HAVE A DEFINITIVE ANSWER; I BELIEVE THE TIRES / LACK OF CRADLE STIFFNESS TO CHASSIS / UNEVEN POWER PLACEMENT DUE TO THE ELSD ALL PLAY A PART IN THE SQUIRLEY BEHAVIOUR.

[JSH]

In its previous and current form, on Toyo R888R 345/45R17, if you breathe on the throttle it breaks loose. However, it behaves much better on MT ETS R 325/50R15, as long as there are minimal turns.