skxf430

I am thinking of going from a 295/30/18 to a 315/30/18 on my C6 Z06but was worried about rubbing.

Has anyone run that size tire up front with success?

Thanks for any info.

AverageVetteNut

I know it's common for us in Stock class SCCA autocrosss to use that tire size on the stock wheel and there doesn't seem to be anyone complaining about rubbing.

Are you concerned with rubbing at full lock when turning, rubbing on the fender, or a combination of that?

froggy47

My friend did on his GS, I think he had a little fender liner rub & I think he was lowered on stock bolts, don't know how far. Seems ok.

skxf430

Yes, I am concerned with any kind of rubbing as I still drive my car on the street too. I would think my Z06 should be able to fit a slightly wider tire than a GS.

RDnomorecobra

I run that on front of a c5z and I don't have any problems. I think c6z has more clearance.

skxf430

I will give them a try.

froggy47

My understanding is they are the same under the fenders. But I could be wrong.

jlutherva

I've run that size Hoosier R6 on 11" CCW wheels with minimal rubbing on the brake duct in full turn situations (paddock). With a 345 rear it gives very neutral handling.
305 fronts and 330 rears also provided neutral handling in my C6Z.

Jim

acrace

I ran that size Hoosier (A6) on my '09 Z06, with factory wheels and lowered on the stock trim height bolts. Just a touch of rubbing on the inner liner. This was for autocross only, and not driven on the street.

Gman57

.... no issues

Supercharged111

Hey, I remember you from July.

Gman57

Yup.... HPR
Great track and I'll be back next year!!

5280Racer

Me too!!! I'm looking forward to lining up next to you!!!

redhot400

I'm running 10.5 C5ZO6 rims and 305's rear and 265 fronts and for the track they are fine, BUT you cannot run them on the street cause they will rub when turning lock to lock. On the track however they are great. My setup causes a little understeer but for me thats great since I'm still a novice HPDE2. Good Luck!

skxf430

I chickened out and I am sticking with the 295's. My Forgelines are 11" up front and the offset would have had the tires sticking beyond the fender lip, and probably would have rubbed at full lock. I drive the car on the street so that wouldn't have worked too well.

Jawnathin

For C6 Z06s, any effect on AH/TC/AB using 315/30/18s paired with 335/30/18 rears?



FRONTS -
Specification | Sidewall | Radius | Diameter | Circumference | Revs/Mile | Difference
275/35-18--------3.8in-------12.8in------25.6in----------80.4in------------788--------(0.0%)
295/30-18--------3.5in-------12.5in------25.0in----------78.4in------------808--------(-2.4%)
315/30-18--------3.7in-------12.7in------25.4in----------79.9in------------793--------(-0.5%)

REARS -
Specification | Sidewall | Radius | Diameter | Circumference | Revs/Mile | Difference
325/30-19--------3.8in-------13.3in------26.7in----------83.8in------------756--------(0.0%)
335/30-18--------4.0in-------13.0in------25.9in----------81.4in------------778--------(-2.9%)

Gman57

You want to use the 345/18 for rear

drivinhard

The 295 will fit (and feel) better on a 11" rim anyway

Jawnathin

Thank you. Unfortunately Toyo doesn't make a 345 for the rear.

However, do you mean 345/30/18 or 345/35/18? I ask because I'm having a similar conversation with tire selection where the 345/35 was recommended.

I found that to be very interesting as the tire size deltas are even larger than the setup in question.

A 345/35/18 is 3.1% taller than the stock sizes and the 315/30/18 is 0.5% shorter compared to the front. That should be a combined 3.6% delta between the front and rear tires compared to stock.

A 335/30/18 is 2.9% shorter. The fronts are 0.5% shorter. Since both are smaller, that should help offset the individual differences and the delta is closer at 2.4% between the front and rear tires compared to stock.

I'm not 100% sure if that's how the math works out for these systems, but it seems to me that keeping the differential between both the front and rear as close as possible would be ideal.

Thanks again.

Jawnathin

Ended up going with the 295s. Based on the feedback with the vendor, they believed the issue was around revs per mile. Stock computer has a delta of approx 32 revs per mile between the front and rears. Anything significantly less will make the computer believe that there is wheel spin and will try to manage power accordingly. Apparently anything more is okay.

The 295/30s and 335/30s are 30 revs apart, 2 away from stock, which should be OK.