Has anyone tried to fit a 18x10.5 / 315/30/18 tire?

[fastTa]

Has anyone tried this size wheel/tire on the rear of a 4th Gen f-body? They are 56mm offset and I already know I will have to do the BFH mod, but I was just curious if I would have to roll the fender to get the tire to clear. Thinking about getting these ZO6 wheels off ebay for my TA:

ZO6 Wheels

[Jay 02 TA ws6]

I am wondering the same thing for the black Z06 wheels Tunder Racing has...

[Injuneer]

Just reference it to the 17x11 50mm offset 315/35-17. That's a 7.93" backspace, 4.00" frontspace. Some cars take no alterations, some take hammering the inner fenders, cutting the edges off the jounce bumper brackets and even recentering the body over the axle with an adjustable panhard rod. Nothing you wouldn't be willing to do for better performance. I did all of those, and also rolled the inner edge of the fender lip up a bit, because the body would move enough on a really hard shift (back in the M6 days) to put that lip into the outside edge of the tire.

Check the specific brand of tire you are usihng with the dimensions shown on Tire Rack. There is a large variance in tire section width, even though they are the same nominal size. I use the BFG 315 DR's which appear to be substantially wider than the Nitto DR's. People report far fewer problems with the Nittos that they do with the BFG's.

The chart I have from VETTE magazine shows the factory 18x10.5" Z06 wheels as a 58mm offset, and that gives just about an 8.00" backspace, 3.45" frontspace. That just enough deeper into the wheel well that its bound to be a problem. Numerous people have confirmed this on the CZ28.com "Wheel and Tire" forum.

You indicated you have a 56mm offset (repro wheel?), and that would alleviate the problem by 0.08" but you are still in the area where you will have a problem rubbing the inner fender if the tire is meaty enough. But once you solve the offset problem, you could avoid hammering altogether. Just a matter of whether you like spacers on the rear wheels. I don't but that's just a personal preference.

[fastTa]

Thanks Fred. What method did you use to roll your rear fenders?

According to Nitto, the largest 18" 555R tire they make is a 305/35 ZR18 with a cliamed overall width of 12.40". And according to Tire Rack the overall width of the BFG drag radial is 12.60". I'd really like to stick with a 315 though.

Fred, have you heard any good input as to the quality and performance of the new M/T drag radials over on cz28. I saw a few people on ls1tech that said they felt like they were quite a bit stickier than their Nitto 555R's.

Just for kicks, this guy is running Forgeline GT3 18x12.5's with a 345/35/18 on the rear of his Camaro. Details in the link:

http://www.ls1tech.com/forums/showthread.php?t=207860