Will 305 tire on 10" wheel have excess roll?

[dreksnot]

Thinking of trying 305/35ZR20 on the front ZL1 10" wheels. The spec for the Michelin tires states it will mount on a 10-12.5" wheel. I do have strut-tire clearance as I have camber/caster plates (not sure about fender clearance with my stock height SS yet, I will have to test fit). I having tires mounted to see about that clearance; however, will the tire suffer from excess roll when corning hard (autocross, road course)?

[dreksnot]

Half update: had the 305/35's mounted on the 10" fronts. I have at least 1/4-3/8" clearance from 6/32" left tread to strut tower, and maybe 3/8-1/2" from section width to strut. They don't look like they stick out of the fender, just flush; but it's going to be close. The car is currently up in the air on my lift so I can't see where they're going to be sitting with the car in a neutral position on the ground. If that looks good, then I'll take the car out on a warmer day and load the front suspension up with hard braking or cornering in some vacant parking lot for a rub test.

[dreksnot]

Ok, so the bulge-out isn't there like I expected it to be and the 305 fit looks pretty good on the 10" wheel.

As for the tire protrusion and the fender - does this look okay? (the car is still up on my lift so the suspension is totally unloaded and drooping). I need to slap on the rear wheels/tire, drop and relook, test drive it hard.

[dreksnot]

And, a verdict is in! To no surprise - a no, go! Got fender rub on the driver's side on a speed bump. I do have some room on the strut side but I still think I'd have the rub issue cornering and braking hard. Guessing it's the 28.7" tire height and the 11.2" tread width. Well, 305 30 20 or just go back to the 295 35 20.

[rich2342]

I currently have a square setup 285/35/20. Needing more in the back, though without adding the expense of 11 inch setup. Sorry to see it didn't work out for you.

How much is the car lowered? perhaps raise up a touch to avoid rubbing if the tires perform and don't roll in the corners?

[dreksnot]

Originally Posted by rich2342

I currently have a square setup 285/35/20. Needing more in the back, though without adding the expense of 11 inch setup. Sorry to see it didn't work out for you.

How much is the car lowered? perhaps raise up a touch to avoid rubbing if the tires perform and don't roll in the corners?

Car is not lowered - stock height.

[shu92870]

Add camber.
-2.0 to -2.5 degree camber should get those tucked in and I don’t think they will rub the inner spring.
Just my $.02

[acammer]

Originally Posted by shu92870

Add camber.
-2.0 to -2.5 degree camber should get those tucked in and I don’t think they will rub the inner spring.
Just my $.02

That could work if it's pretty close to zero'd out already. Depending on where it's at now, it could also take you way past what you want in order to get it clear. Worth checking for sure.

As for the tire rolling over the wheel, you might be ok unless you run some fairly low air pressure. I have had an NT555G2 (285/35/20 on a 20x9) roll up onto the shoulder pretty hard at an impromptu road course event where I could really load that tire hard. It was a front tire, I don't think I could load a rear tire hard enough to do it. Tight opening but increasing radius corner where I could progressive just lean into the tire and hold it right on the limit. It didn't jump off the bead, but it sure was a weird feeling, and obviously comes with a sudden change in grip. Air pressure was low, probably 30psi, and I think with 38+ pounds in the tire it may not have been so eager to flop like that. The wear marks on the shoulder made it pretty obvious what had happened, they were way over the side!

[shu92870]

I now run 305/30/20 square.
Ona 200TW tire they seem to be the easiest to acquire.
No roll on the front with a little more air pressure @ 31 cold pre track.