ktlocklear

I'm planning to run 4, rear 18x10.5 speedline z06 wheels on my 2004 z06 for HPDE events and would like to run a "square" R Comp tire size. What is the recommended, squared tire size? The car is just lowered on stock bolts for now, but plan on doing coil-overs in the near future.

Thanks for any help

JeremyGSU

I've heard running anything wider than a 285 in stock configuration is too big. I run 285's and they already rub if I turn the wheel too much. I've seen guys running 315 squarred before but that was on a full race car with no fender lining.

r.hillenbrand

I run 295 square on them and the fronts rub on the cooling ducts if I turn too far.

RDnomorecobra

anything from 285/35 to 315/30 fits fine. I have a dual use street/track car and have not had a problem. I do try and avoid full lock of the steering wheel with the 315's but have not really felt hindered by that. I tried 315/35's once and were too tall in my opinion. of course make and model of tire varies in size a bit even with same size stamped on the side.

StreetSpeed

The stock cooling ducts or aftermarket? I just bought my 04Z and it came with a square 295 setup as well. I have the quantum cooling kit on order and was wondering if it was going to cause some rubbing issues.

r.hillenbrand

I have the DRM aftermarket. I have had them on for over a year and it only happens when it is on the street at full lock. I am aware of it and when backing or turing I just don't go full lock on the radius.
I am sure it is because the offset of the rear wheels being on the front. When on track I have never noticed any rubbing on the cooling setup. Look in the wheel well and see if there are any markings on them from turning or have someone turn the wheel and look at where it stops.

Z06TWT

Been there,done that . On my 02Z I installed DRM ducts and 18 square wheels. I used a 12mm spacer on front to clear my BBK and have no rubbing with 295s on front and 305s rear. I also have MTI coilovers so no issues. My advice is to keep a slight stagger for now if you want to use the comp mode for new tracks or wet days. There are many posts talking about how to measure the tire diameter to maintain the factory controls.

ktlocklear

Thanks for the input everyone!