I got a set of HR5 Hellraisers and Continental DWS 06 AS tire, staggered. Since I put them on the car feels squirmy at WOT. It happens from a stop and when I'm at speed. Even if I'm on the freeway it feels squirmy when I hit the gas WOT.
I know squirmy is not an official automotive term. To better bescribe the sensation, when I go WOT it feels like the car acceleration is pulsating. Even though my foot is 100% down it feels like I'm bouncing the pedal from 95% to 100% and back and forth.
More details: Car is a 2018 Scat Pack, basically stock.
The RPMs stay consistent and do not pulsate, it's not the engine.
When driving normal the car goes in a perfectly straight line and I had the alignment check a few months and, front and back, and it was in spec. according to the shop.
On the back I have 315/35R20 Continental Extreme Contact DWS 06 All Season tires on 10.5" HR5 wheel. The tires grip so much better than the stock RSAs, it's night and day better, but the pulsing concerns me. The front is the 9.5" HR5 with a 275 Conti DWS 06. I dont think the staggered setup ia the issue.
The car was not squirmy before when I had the WRT wheels and stock RSA tires. I put 275/40 BFG Gforce Comp-2s on just the back before I got the HR5s and it was not squirmy then either. It did walk to the left pretty good when I was doing burn outs though. I'm pretty sure the rear alignment needed some work. I had a shop check, but it was not a specialty shop and they just said it was "in spec". I shouls have had them tell me the numbers. But the car drives straight under normal conditions and corners fine, it's only at WOT when it pulses.
The pulsing is mostly front to back. If there is any left/right wiggling I can't feel it, but that doesn't mean there isn't any, its just not as noticeable as the push-pull going on.
So, I'm thinking its something in the rear suspension. I know that having wider wheels and tire with a different offset will change the alignment. My first step is to take it a shop that does custom alignments and get that checked. If that doesn't fix it I'm thinking some of the stock parts are flexing, bushings or control arms. I might even need to get adjustable control arms to get the alignment I want anyway (0.5 camber in the back with just a little toe in, 1.2 in the front with just a little toe out).
Now for my questions:
Any and all input is welcome. I have a good amount of knowledge with suspension but none when it comes to fixing issues like this.
Thanks.
I know squirmy is not an official automotive term. To better bescribe the sensation, when I go WOT it feels like the car acceleration is pulsating. Even though my foot is 100% down it feels like I'm bouncing the pedal from 95% to 100% and back and forth.
More details: Car is a 2018 Scat Pack, basically stock.
The RPMs stay consistent and do not pulsate, it's not the engine.
When driving normal the car goes in a perfectly straight line and I had the alignment check a few months and, front and back, and it was in spec. according to the shop.
On the back I have 315/35R20 Continental Extreme Contact DWS 06 All Season tires on 10.5" HR5 wheel. The tires grip so much better than the stock RSAs, it's night and day better, but the pulsing concerns me. The front is the 9.5" HR5 with a 275 Conti DWS 06. I dont think the staggered setup ia the issue.
The car was not squirmy before when I had the WRT wheels and stock RSA tires. I put 275/40 BFG Gforce Comp-2s on just the back before I got the HR5s and it was not squirmy then either. It did walk to the left pretty good when I was doing burn outs though. I'm pretty sure the rear alignment needed some work. I had a shop check, but it was not a specialty shop and they just said it was "in spec". I shouls have had them tell me the numbers. But the car drives straight under normal conditions and corners fine, it's only at WOT when it pulses.
The pulsing is mostly front to back. If there is any left/right wiggling I can't feel it, but that doesn't mean there isn't any, its just not as noticeable as the push-pull going on.
So, I'm thinking its something in the rear suspension. I know that having wider wheels and tire with a different offset will change the alignment. My first step is to take it a shop that does custom alignments and get that checked. If that doesn't fix it I'm thinking some of the stock parts are flexing, bushings or control arms. I might even need to get adjustable control arms to get the alignment I want anyway (0.5 camber in the back with just a little toe in, 1.2 in the front with just a little toe out).
Now for my questions:
- Has anyone else had this issue?
- Anyone think it might be something in the drive train and not the suspension.
- Does the Hellcat have the same rear control arms ans bushings as the Scat Pack?
- would a tighter rear sway bar help?
Any and all input is welcome. I have a good amount of knowledge with suspension but none when it comes to fixing issues like this.
Thanks.