[Z OH 6]

Originally Posted by mlee

In my 2017 I tried different tires with no help at all. Mine consistently went side to side under hard throttle and got worse with MT DRs. So bad under a full launch I could barely keep it in my lane. Tires are not the issue but may very well be alignment. After I had it aligned and bushings replaced it stopped but I also didn't keep the car very long after that to really test.

I think tires are a contributing factor just like many other things. The BMR rear cradle lockout also helps tremendously on the standard ZL1.

[SATINSTEEL1LE]

Its the ELSD doing its magic to keep you straight and with traction. Why is this a 24 page thread??? LOL

[raptor5244]

Originally Posted by SATINSTEEL1LE

Its the ELSD doing its magic to keep you straight and with traction. Why is this a 24 page thread??? LOL

I sometimes feel the rear wag back and forth a bit under hard acceleration but I figured it was normal and does feel like the e-diff is controlling it. I also notice the e-diff control a lot more on hard turns vs. standard LSD under acceleration and you can relax it a bit in the different track modes.

[Mark R]

Originally Posted by SATINSTEEL1LE

Its the ELSD doing its magic to keep you straight and with traction. Why is this a 24 page thread??? LOL

What??? This thread exists because the ELSD is NOT doing its magic, and cars are wiggling in the back under hard acceleration.

[Z OH 6]

Originally Posted by Mark R

What??? This thread exists because the ELSD is NOT doing its magic, and cars are wiggling in the back under hard acceleration.

Exactly.

[Krowser]

Originally Posted by Mark R

What??? This thread exists because the ELSD is NOT doing its magic, and cars are wiggling in the back under hard acceleration.

The "wiggle" is coming from the soft rubber bushings on the diff cradle.

The fix is either:
1. dropping the cradle and replacing the soft rubber bushings with the stock zl1 1le solid aluminum bushings

2. purchase the BMR rear cradle lock out kit. the kit does not require you to completely dropping the cradle..

[raptor5244]

Originally Posted by Krowser

The "wiggle" is coming from the soft rubber bushings on the diff cradle.

The fix is either:
1. dropping the cradle and replacing the soft rubber bushings with the stock zl1 1le solid aluminum bushings

2. purchase the BMR rear cradle lock out kit. the kit does not require you to completely dropping the cradle..

Does the wiggle only happen while the e-diff is making its corrections? I only notice it once in a while but it is very slight and slow wag during the pull but does't feel like I am going to lose control or anything.

[Krowser]

Originally Posted by raptor5244

Does the wiggle only happen while the e-diff is making its corrections? I only notice it once in a while but it is very slight and slow wag during the pull but does't feel like I am going to lose control or anything.

Im not a suspension engineer, so this is my opinion.

When you accelerate, all of the weight is transferred to the rear of the vehicle.
The diff is attempting to disperse torque evenly between the axles.
The tires and rotating mass is consistent, what's not consistent is the road interacting with the tires and the flexing of the soft rubber bushings in the cradle.

By eliminating a large amount of flex, the diff is more stabilized to transfer torque more evenly, therefore putting more power to the ground. This results in more stabilization of the suspension while moving and steering.

The downside is harder cradle bushings may result in more NVH.

[SATINSTEEL1LE]

NO absolutely not. There is no physical movement of the rear cradle. Someone put a gopro on the underside and SHOW US the actual movement. This is a normal condition of the elsd/stability control.

You can eliminate this by using the PTM modes like sport 1,2 and race. You will see the "wagging" goes away as the car lets the rear do what it wants traction wise. The car will do all sorts of weird things like lock the outer front tire to stop fish tailing. You can see it in the motorweek videos of the ZL1 release when they are trying to drift it. The car does not want to do that, and uses many systems to keep traction. You people are INSANE!.....AHAHAHa

Starting at 3:27 you can see the car locking the front outer wheel to stop a drift as I said. THis is normal as is the rear wagging as the car grabs individual rear brakes to keep you going forward with no spin.

[Z OH 6]

Originally Posted by SATINSTEEL1LE

NO absolutely not. There is no physical movement of the rear cradle. Someone put a gopro on the underside and SHOW US the actual movement. This is a normal condition of the elsd/stability control.

You can eliminate this by using the PTM modes like sport 1,2 and race. You will see the "wagging" goes away as the car lets the rear do what it wants traction wise. The car will do all sorts of weird things like lock the outer front tire to stop fish tailing. You can see it in the motorweek videos of the ZL1 release when they are trying to drift it. The car does not want to do that, and uses many systems to keep traction. You people are INSANE!.....AHAHAHa

Starting at 3:27 you can see the car locking the front outer wheel to stop a drift as I said. THis is normal as is the rear wagging as the car grabs individual rear brakes to keep you going forward with no spin.

The rear cradle absolutely moves under stress. There's a reason why the 1LE comes with solid bushings and why the BMR cradle lockout kit solves this issue for most people.

[pauly1119]

With all that said an alignment fixed mine today for 129.00 including tax. There are several people here that have had the problem resolved with a alignment. Hard to ignore the facts.

[Z OH 6]

Originally Posted by pauly1119

With all that said an alignment fixed mine today for 129.00 including tax. There are several people here that have had the problem resolved with a alignment. Hard to ignore the facts.

Same with the rear cradle lockout kit and some with just a tire swap, so we're back to square one.

[Joshinator99]

Originally Posted by Mark R

What??? This thread exists because the ELSD is NOT doing its magic, and cars are wiggling in the back under hard acceleration.

Originally Posted by Z OH 6

Exactly.

Bingo! Also, FWIW this happens to us peasants with SS cars too (no eLSD on non-1LE models).

Originally Posted by Z OH 6

Same with the rear cradle lockout kit and some with just a tire swap, so we're back to square one.

Yep. It doesn’t seem to be one clear cut answer for every situation.

[Krowser]

Originally Posted by SATINSTEEL1LE

NO absolutely not. There is no physical movement of the rear cradle. Someone put a gopro on the underside and SHOW US the actual movement. This is a normal condition of the elsd/stability control.

You can eliminate this by using the PTM modes like sport 1,2 and race. You will see the "wagging" goes away as the car lets the rear do what it wants traction wise. The car will do all sorts of weird things like lock the outer front tire to stop fish tailing. You can see it in the motorweek videos of the ZL1 release when they are trying to drift it. The car does not want to do that, and uses many systems to keep traction. You people are INSANE!.....AHAHAHa

Starting at 3:27 you can see the car locking the front outer wheel to stop a drift as I said. THis is normal as is the rear wagging as the car grabs individual rear brakes to keep you going forward with no spin.

I think you need to do a little more research.

There is a reason why the zl1 1le has solid rear bushing in the diff cradle.

If what you say here is true, GM would have the same bushings in the zl1 and zl1 1le.