Tail wagging on hard acceleration
Thread Starter
Racer
Joined: Sep 2016
Posts: 304
Likes: 67
From: Bay Area CA
Tail wagging on hard acceleration
Hi All, 17 z07 with 700 miles, just replaced the tires and rims to 20x10.5 and 21x13, pirelli zero corsa system 295 and 355.
Now under hard accel in 2nd or third gear the rear starts going side to side as if its got rear steering. I have to let off to get it under control. Seems to happen at lower speeds upwards of 80mph. then it kinda dies down when in 3 digits.
Still very scary 'cuz cant tell if its going to mellow out or get more violent and loose control.
I had the same issue with my supercharged C5 after installing new tires and rims.. but killed that car after couple hundred miles of the upgrades so never found out the cause but the rears tires had very soft walls so I thought that might be the contributor.
Has anyone experienced this? I'm thinking possible issue with the toe alignment? Intelligent or experienced responses only please. Thank you in advance.
Now under hard accel in 2nd or third gear the rear starts going side to side as if its got rear steering. I have to let off to get it under control. Seems to happen at lower speeds upwards of 80mph. then it kinda dies down when in 3 digits.
Still very scary 'cuz cant tell if its going to mellow out or get more violent and loose control.
I had the same issue with my supercharged C5 after installing new tires and rims.. but killed that car after couple hundred miles of the upgrades so never found out the cause but the rears tires had very soft walls so I thought that might be the contributor.
Has anyone experienced this? I'm thinking possible issue with the toe alignment? Intelligent or experienced responses only please. Thank you in advance.
Safety Car
Joined: Jun 2003
Posts: 4,250
Likes: 656
From: San Diego Ca
Hard Accel? Tires losing traction? What mode are you in. The ediff may just be learning the new tires. It measures a number of things and decides how to lock or not lock the diff for you. Thinks like mode (W, E, T, S, Tr), steering angle, tire slippage, etc.
If you have the steering wheel dead straight and the car in any mode the ediff should be locking and you should not have any side to side movement. You could also be experiencing traction control a bit again depending on settings. Given only 700 miles learning the car in T will give you a lot of electronics protecting you and your $100k investment until you are totally comfortable and experienced with the car and what it may do.
If you have the steering wheel dead straight and the car in any mode the ediff should be locking and you should not have any side to side movement. You could also be experiencing traction control a bit again depending on settings. Given only 700 miles learning the car in T will give you a lot of electronics protecting you and your $100k investment until you are totally comfortable and experienced with the car and what it may do.
Last edited by pkincy; Mar 25, 2017 at 10:57 PM.
Drifting
Joined: Sep 2008
Posts: 1,884
Likes: 210
From: Somewhere on earth
Mine does it in any mode at those speeds, on OEM wheels and tires. Normal for this car. Traction control can't keep up with this much power and instant TQ delivery. It wags its tail, but eventually falls back into line.
Throttle control is the key here. No mashing the throttle in this car...
Throttle control is the key here. No mashing the throttle in this car...
Thread Starter
Racer
Joined: Sep 2016
Posts: 304
Likes: 67
From: Bay Area CA
Hard Accel? Tires losing traction? What mode are you in. The ediff may just be learning the new tires. It measures a number of things and decides how to lock or not lock the diff for you. Thinks like mode (W, E, T, S, Tr), steering angle, tire slippage, etc.
If you have the steering wheel dead straight and the car in any mode the ediff should be locking and you should not have any side to side movement. You could also be experiencing traction control a bit again depending on settings. Given only 700 miles learning the car in T will give you a lot of electronics protecting you and your $100k investment until you are totally comfortable and experienced with the car and what it may do.
If you have the steering wheel dead straight and the car in any mode the ediff should be locking and you should not have any side to side movement. You could also be experiencing traction control a bit again depending on settings. Given only 700 miles learning the car in T will give you a lot of electronics protecting you and your $100k investment until you are totally comfortable and experienced with the car and what it may do.
Tech Contributor
Joined: Oct 1999
Posts: 41,066
Likes: 9,829
From: Charlotte, NC (formerly Endicott, NY)
Might want to have the rear toe checked. It might be toed out a little too much. That could cause the back end to move around a little under hard accel.
Bill
Bill
Le Mans Master
Joined: May 2000
Posts: 8,729
Likes: 1,508
From: Redmond WA
Mine rear-steers a lot with drag radials, but track pretty much perfectly with the stock MPSS tires. For a road trip or similar I'd definitely want the MPSS back on there.
For city streets and to-from the track, the Nittos aren't bad, but they rear-steer some on their own too, though nothing like the spooky MT ET Street SS tires. They had two minds of their own and didn't always agree with each other!
For city streets and to-from the track, the Nittos aren't bad, but they rear-steer some on their own too, though nothing like the spooky MT ET Street SS tires. They had two minds of their own and didn't always agree with each other!
