Tracking on less than perfect wheels
 

So big track newb here.. long story short. Found out 3 of 4 OEM wheels on my C7Z06 are out of round, slight but noticeable when spun, and its pretty slight while driving. See video..

Since dealer wont replace, lack of warranty and such.......... I'm curious, would you use it for tracking, or am I just asking for trouble? And if so, what sort of trouble?

Side note.. man do these OEM wheels stink or what?!?

If it doesn't cause vibration, fine for running on track. A lot of us don't bother to balance wheels if just used on track.

Why are they out of round? Any impacts? I would just make extra certain to inspect for any cracking.

Yea that's what I've ben trying to determine.. I don't recall hitting anything major, 8k miles so far.. its been to 2 track days, but I also don't recall any major event on track to do that. 3 of 4, weird. I could see bending 1 or 2 on the same side but who knows.

I read that these wheels have a bad rep for being 'weak', I think that even a sun spot would bend them out shape :(

Good point on checking for cracks, I will have to do that!

There are shops that specialize in wheel straightening and wheel repair. Even alloy wheels can be repaired/straightened.

Inspect for cracks first. I would never use a cracked wheel.

If no cracks, I'd have it measured on a road force balancer and see what you can get the numbers down to with proper mounting and balancing. If you can get it reasonably straight with mounting the tire the right orientation, I would run them. If not, I'd have them straightened.

The down side to shaky wheels is that you absolutely won't get maximum braking force or cornering force from them. There will be some variation in force between the tire and the road as the wheel turns, and at the "lightest" point, the thing could stop or transition from gripping to sliding. How bad that is depends on how close to the limit you drive on the track, and how much variation there is in force as the wheel/tire assembly turns.

Awesome, thanks for the insight!

I read somewhere on this forum that GM's policy on these wheels were that they shouldn't be straightened. Not that a warranty would guarantee me for repairs due to track use (despite what should be the contrary).. I'd hate to have an broke wheel event because I straightened them when I shouldn't have and make worse the chance of being warranty covered. But still, it all depends I guess. Some have told me why even track it on suspect cast OEM wheels anyway, be real and get a forged set.. :( lol. Current wallet level doesn't allow for a separate track wheel set yet... but when it does, I'm on the fence between 18s vs 19s. the track rabbit hole is only begun for me hahah

Anyhow, I took the wheels to Discount Tire and they attempted to balance them as best they could despite the wobble. I'll inspect it closer for cracks and see how they fare. Thanks!!

Depends on kind of wheel as well. A steel wheel will survive anything. I'd be leery of a cast wheel that is much out of round as they crack depending on porosity, forged will stay together a lot better. Slicks and cheap wheels do not always go well together.

My rule of thumb is 060" out trash can. They only get worse not better. more vibration increases stress on wheel. In the old T1 days we ran CCW's with drawn metal lips. I used to rebend those when they got to 040 out. I would not bend a cast wheel. Worst wheel failure is when spokes brake under braking and you hit the wall. That's a bad day...

:iagree:
I've seen much worse, and (surprisingly!) with no vibration problems. But to me, that's bad enough to warrant replacing on a street car, and I wouldn't track it.
Last thing on earth I'd do is have a race wheel straightened.
No good things are going to come from that...

+1

If you can feel the vibration then its putting extra stress on the wheel, hub, axle, etc. Given enough time those parts will wear and even break. Take it from someone who has ruined his fair share of hubs - having one explode on track leaving nothing more than the caliper holding a wheel on is not fun.

I've tracked on worst wheels. And tracked them heavily. Two things to consider.

1: Are they holding pressure?

2: Can the wheels/tires still be balanced?

If yes on both, I wouldn't worry TOO much. Heck on one set of track wheels, the tire grip was so strong that the tires have a tendency to move on the rims about 1/4" on very heavy braking. The wheels do not have "knurled beads" to prevent a mounted tire from rotating. So eventually they go out of balance after a few track days and I usually leave it until I unmount and flip to extend the life of the track tires.

If you track extensively, maybe it's time to get a separate set of rims/tires for track.

I can prevent that 100% of the time when I mount my tires and wheels. If I'm traveling and I have to pay Hoosier my tires spin on the wheel. There is a reason for that.

i tracked a bent replica wheel for over a year. never had any issues. didnt noticed any vibs either, but it was a rough and old concrete track.

Me personally, I'd never run that. It's going to upset the suspension on every rotation.