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S197 Bump steer excessive tire wear

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254
119
Exp. Type
HPDE
Exp. Level
Under 3 Years
Nova Scotia Canada
After 3 track days in a row without rotating tires (yes I know. Stupid idk what I was thinking) this is what the insides shoulder of my 2 front tires look likeIMG_0483.jpeg

The tire on the right is the front right and the left is the front left. Both inside shoulders facing inward. Atlantic Motorsport Park is the track and it is a heavy right turn track so the front right tire is often unloaded and I’m guessing it’s wearing due to bumpsteer. If anyone else has any other insight that would be awesome!IMG_0353.jpeg

Going to be ordering a bump steer kit. Any recommendations are also welcome
 
I’m a little jealous, I haven’t been able to get my inside edges to wear faster than outside on track in a long time. What are your camber and toe settings? Are you driving those on the street at all?
 
After 3 track days in a row without rotating tires (yes I know. Stupid idk what I was thinking) this is what the insides shoulder of my 2 front tires look likeView attachment 110372

The tire on the right is the front right and the left is the front left. Both inside shoulders facing inward. Atlantic Motorsport Park is the track and it is a heavy right turn track so the front right tire is often unloaded and I’m guessing it’s wearing due to bumpsteer. If anyone else has any other insight that would be awesome!View attachment 110373

Going to be ordering a bump steer kit. Any recommendations are also welcome
Both inside edges worn = too much negative camber.
 
-3.6 camber and 0 toe, no street milage at all
Honestly I’m kind of surprised. Seeing your Ford K springs in your build sheet, those aren’t crazy low. I wouldn’t expect that you have a major bump steer problem, but maybe?

I guess I would either back off the neg camber a bit or push harder in the corners lol.
 
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Honestly I’m kind of surprised. Seeing your Ford K springs in your build sheet, those aren’t crazy low. I wouldn’t expect that you gave a major bump steer problem, but maybe?

I guess I would either back off the neg camber a bit or push harder in the corners lol.
The thing is. There are only a couple left Hand turns at AMP (not in Atlanta) and I’m already sending it hard through those corners. I think I’m gonna throw a bump steer kit at it and see what that does
 
Others on here know far more about bump steer than I do, and I’m not suggesting it isn’t important. But AI and Google are suggesting that bump steer typically causes toe IN on an S197 under droop. I don’t know if that is accurate. If it is, and if bump steer were the problem, it doesn’t make sense that your front right would suffer worse inside wear than the front left on your mostly right handed track.
 
Others on here know far more about bump steer than I do, and I’m not suggesting it isn’t important. But AI and Google are suggesting that bump steer typically causes toe IN on an S197 under droop. I don’t know if that is accurate. If it is, and if bump steer were the problem, it doesn’t make sense that your front right would suffer worse inside wear than the front left on your mostly right handed track.
Yeah, bumpsteer is inconsistent toe change under compression and droop. E.g. if you are in a turn and hit a bump, the car steers without you moving the wheel. Ackerman could be an issue here, but that's not exactly adjustable. A bumpsteer kit is a waste of money.

Personally, I'd pull some camber. You might have too much for the load you are putting on the car on that track.
 
Yeah, bumpsteer is inconsistent toe change under compression and droop. E.g. if you are in a turn and hit a bump, the car steers without you moving the wheel. Ackerman could be an issue here, but that's not exactly adjustable. A bumpsteer kit is a waste of money.

Personally, I'd pull some camber. You might have too much for the load you are putting on the car on that track.
Taking camber out is a pain in the ass, I run vorshlag plates and change them for every track day and at the moment they run at max on track


I run my caster setting at the middle on the plates. Could this cause this issue. More/less camber gain when turning?
 
Taking camber out is a pain in the ass, I run vorshlag plates and change them for every track day and at the moment they run at max on track


I run my caster setting at the middle on the plates. Could this cause this issue. More/less camber gain when turning?
No. Caster is not a tire wearing angle.

With all that malarkey moving the plates around (not a fan of this) are you sure toe is still zero?

It seems changing camber is less painful than installing a bump steer kit that also will require an alignment and not fix the problem?

If you are moving it anyway, move it less.
 
No. Caster is not a tire wearing angle.

With all that malarkey moving the plates around (not a fan of this) are you sure toe is still zero?

It seems changing camber is less painful than installing a bump steer kit that also will require an alignment and not fix the problem?

If you are moving it anyway, move it less.
The issue with setting it to anything less then maximum or minimum is getting both sides the same.

What I’ve done is set the camber at maximum and the toe at 0. When the camber comes out the toe goes in a bit. I’ll have to check my alignment again I suppose to be 100% sure but the steering wheel is straight and the car doesn’t pull
 
The issue with setting it to anything less then maximum or minimum is getting both sides the same.

What I’ve done is set the camber at maximum and the toe at 0. When the camber comes out the toe goes in a bit. I’ll have to check my alignment again I suppose to be 100% sure but the steering wheel is straight and the car doesn’t pull
Maybe you do not need both sides to be the same if there are only two left hand turns at AMP (not in Atlanta). Back the left side down just a tiny bit, and back the right side down substantially.
 
The issue with setting it to anything less then maximum or minimum is getting both sides the same.

What I’ve done is set the camber at maximum and the toe at 0. When the camber comes out the toe goes in a bit. I’ll have to check my alignment again I suppose to be 100% sure but the steering wheel is straight and the car doesn’t pull
Find some sort of spacer to put in there so it doesn't move as much down?

I don't mean it disrectfully at all, so please don't take it that way - you seem to be doing a lot of guessing and a lot of extra work to ignore the problem staring us in the face. It's almost 99% too much camber causing the wear assuming the alignment is still correct. But with all the moving around the plates, it needs to get on a rack and be checked to make sure it is what you thought it was.

Assuming you don't have an alignment rack handy :) can you check toe with plates?

I really feel like there is an actual alignment issue here, but that is just a wild guess.
 

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