hungryhippo

Hopefully this picture link works. My passenger front tire is feathering bad. I checked the front toe with a tape measure , checked the eccentric bolts(they are marked), and check for a bent wheel. Everything seems fine. Car tracks straight with no vibrations. Hard to see, but each horizontal tread pattern has a 2/32" lip sticking out. Any ideas from anyone? Thanks


http://s1160.photobucket.com/albums/...er_media_share

Sidney004

You need to upgrade to an R compound, you've exceeded the capabilities of what a street tire is designed to do. You probably could use more camber as well.

taken19

Link doesn't work for me. Can you post the pics directly into the thread?

AU N EGL

Wonder if your bushings are shot.

Out edge wear can mean not enough negative camber.

hungryhippo

I think i fixed the link, very hard on a phone lol. I am using the pfadt's alignment specs for a street car with slicks, that's as aggressive as I'm willing to go. I'm not worried about wearing down the tires, just the abnormal looking wear.
I'm definitely not ready to run slicks yet. I will check out the bushings. The car has under 20k miles and 12 track days on it.

taken19

I would guess that the excess rubber is beginning to melt and fold into the groove on the track. Once the tire cools off, the buildup is relaxing and creating the lip you're talking about.

You also mentioned you're running an alignment for street car with slicks - about -3.0 camber. Street tires won't do very well with this and you should be in the -1.8 to -2.0 range. Not sure if that's contributing to the issue you are seeing or not.

VetteDrmr

Looks pretty normal to me for a street tire being used at (and maybe a bit beyond) its limits on a track. Whether you move up to something like a Toyo RA1 or Nitto NT01 or stay with your current tires I think you'll be fine.

If by R compounds you're thinking of Hoosiers or Kumho V710s I wouldn't go to those simply because you're running a DE, a non-competitive event, and those tires are $$$$ for their life expectency.

HTH, and have a good one,
Mike

brkntrxn

Looks normal to me as well. My thoughts are exactly as taken19 commented.

AU N EGL

larryfs

Incorrect Toe. too much toe in or out. It's called feathering.

Canam

If your static toe settings are correct and this problem is a toe issue, that means something is changing on track to cause excessive toe probably during loading or cornering. Suspension deflection. You'll need to check every suspension component for loose bolts, something worn, a weak or broken spring, stuff like that. Was your car aligned with you in it or weight of equal value? Bump steer can also cause this. Did you do a bump steer alignment?
Suspension deflects during cornering. Its just a matter of how much. Less is better of course.

VetteDrmr

Well, if the OP is running what I think he is (a street car at a DE), he's running street tires, it's time to breathe a bit.

If I'm correct, he's not running spherical bearings in the suspension, it's not corner weighted, he's just out having fun with his car.

Of course rubber bushings deflect. Of course his alignment isn't optimized for the track, it's a *street* car. Bolts don't loosen, slip, then slip back to the correct settings. Broken transverse leaf springs will either allow more deflection statically (depending on where the break is) or will break totally.

Doesn't mean the alignment hasn't shifted, but he said in post #1 that he checked the toe (assuming it was correct since nothing else was mentioned), no visual slipping of the eccentrics, etc.

My guess is he was running a CCW event, which would put more strain on the passenger side tires.

So I suggest 1.) relax, 2.) have a Happy Thanksgiving!

Have a good one,
Mike

brkntrxn

Guys, he ran his street tires very hard on the track with his street car. End of story.

Canam

oops, just saw the Kuhmo tire. Thought they were 888's.
what they said

VetteDrmr

Now where's the fun in that???

brkntrxn

LOL.

He probably had more fun on those street tires that if he was on R-comps. I miss making a car squeal like a pig while doing four wheel drifts and leaving black marks shifting to 4th.

froggy47

Looks ok to me for a street car on street tires on a track. If he went the other direction it would probably be the other front tire.

Relax.

hungryhippo

Hey everyone, I appreciate the input. Yes, they are just kuhmo XS tires in stock sizes, it is more of a street car than track car. Now that I think about it more, i only seem to notice the feathering on the passenger side at Thunderhill which is CCW and has very hard lefts. This is also the track I have the most time at, so maybe I'm getting faster. I will be putting my street pads back on for the winter tomorrow and I'll double check the suspension and steering.

flyloeZ06

Looks like my Michelin PS2 ZP's after a weekend HPDE.

DansBlkonBlkZ06

Kevin, You still do that on Hoosier A6s!