jeff49

I need help with tire sizes for C5 Z06 18 10.5,17 9.5 wheels. Id like to go as wide as possible or does that matter? If i ran 315 on the rear what would I run on the front. Im looking to buy The Kumho V710s they will go on my 01 coupe. Thank you.

gonzalezfj

I assume we are talking about SCCA Super Stock.

If you are serious about autocrossing, forget the 710s. Somebody on Hooiser A6s will clean your clock.

There is nothing out there faster than the Hoosier A6.

For a C5Z you can use 315 rears and either 275 or 295 fronts on the stock wheels.

Go to driving school. Best of luck to you.

Frank Gonzalez

jeff49

yes Im running stock

fej

275/40 Front's most likely, can't remember is hoosier makes a 285 or not. You will bulge the 295's with the A6 a fair amount, and I have not personally A/B'd them to tell you if the 295 with more bulge is better than the 275 and less bulge. The A6 is a pretty wide tire.

A6 is the way to go for the "R" rubber as mentioned.

Not sure if you have any experience with AutoX, but you might want to spend at least a few events on street tires to see if you are interested enough in dropping $1400+ on a set of Hoosiers.

Seat time is king, and with today's "street" tires, the gab between R rubber and the street rubber has dropped in half IMO. Used to be worth 4 seconds on a 60 second course, I would say 2 seconds nowadays, maybe less.



I am reworking my post, as I did not realize that you are in a coupe. I think you are going to have to stay 275/295. Maybe the coupe guys can chime in. I was thinking z06 rim sizes, and I think you are 17x8.5 and 18x9.5 in the coupe. Can you get bigger tires mounted? Maybe, but I don't think you will truly benefit from the increased contact patch due to the sidewall bulge. To be honest I am not sure 275 works in the front, might have to go a bit smaller.

G'luck
Fej

Solofast

People have run both the 295's and the 275's on the stock Z06 fronts and there doesn't seem to be a lot of speed difference. The fatter tire is more rubbery, but there isn't much difference in lap times.

The 275 Hoosiers can easily fit on an 8.5 inch rim, the Solstice runs 285's on an 8 inch rim and that works really well. Despite the recommended sizes a lot of autocrossers have been "squeezing" A6's onto some skinny rims with a lot of success.

You can't get away with that on a V710, but other than having the guy at the tire shop hating your guts, go for the Hoosiers.

drivinhard

The 275/295 ho ho's are closer in tread width than the sidewall says. They say 10.3" vs 10.8" in specs, but on the 18's, they are even closer than that.

You can put a 295/17 on the OEM 17x9.5, but I bet $100 it's not any faster than a 275/17 on the same wheel.

My .02

VetteDrmr

I haven't stepped up to A6 compounds yet, but I've been running 275/305 Toyo RA1s on stock wagon wheels autocrossing with good results. My alignment is a compromise between autox and street use, and I have good tire wear with one flip required for both the RA1s and the street tires.

HTH, and have a good one,
Mike

Solofast

It comes down to what you are comfortable with. Some people want a sharper turn in that the 275 has, others are happy with a little more sidewall flex and that prevents them from going "over the top" on turn in.

I haven't tried the 275's, and the smaller tire could get hot faster. OTOH, the 295's seem to run with a bit less pressure and with lower pressure you generate heat faster, so there's pluses and minuses for each tire.

I've said before that sometimes "wider isn't better", it depends on the tire, the setup, the surface, the driver, the phase of the moon......

That said, the 285's kick butt on the Solstice, better than any other skinnier tire by far. That's what makes this a sport, you have to go out and find what works, for you, your car and where you are running. I won't necessarily be the same for everybody.

TedDBere

Hoosier A6s: 295/315
Kumho 710s: 275/315

(Hoosiers are currently faster)

Good luck.

R Mackow

I've tried A6s and V710s. I'm running the 710s now for AX and HPDEs. I got tired of scraping stones off the A6s.