cudadude

Hello forum members, I've recently been bitten by the autox (as well as 1/4 mile) bug and have a couple of questions about tires. First, I can't afford three sets of rims (one for street and the other two for racing). So, the one extra set has to do double duty for autox as well as the periodic trip down the track. My question is what tires do you recommend? (I know the demands of the autox and the strip are different - I'll be doing more autox than strip.) Next, I have been unable to find any competition tires that will fit 19" rims (I have a C6). Any suggestions here? Thanks all. Tom

gkmccready

If you've got a C6 non-Z06 there's nothing that fits the rear. Well, that's not entirely true. You can wedge a Z06-sized 325 Hoosier onto it, apparently, but you couldn't/shouldn't drive that on the street if you want more than 500mi on the tire. :-)

If you search this forum, though, you'll find lots of different recommendations for 18" rear wheels and tires for the C6 ranging from C5 Z06 rears (18x10.5) to CCW custom fit. And with an 18in rear your tire choices open up substantially.

In fact, if you have a C6 base (non-Z51) you can easily run 17in all around and then you have even more tire choices...

cudadude

So an 18" is no problem on the rear?

gkmccready

Just keep the right Front:Rear proportions for tire height if you want to run with Traction Control and/or Active Handling. Otherwise an 18" rear should work just fine, a 17" should also fit just fine in appropriate sizes (I'm not certain about clearing Z51 brakes, you'd have to check).

Note that this'll kill your autocross classing, though. SCCA'll bump you to ASP, and WSCC will shuttle you off to E2 (up to 11" wide rim) or E3 (>11" wide).

Joe_G

I run 275-40-17 and 305-35-18 Nitto 555RII's on C5 wagon wheels and they fit and work great. I have Z51 so I have to run C5 caliper mounts and C5 rotors up front (which are cheap from Napa).

They are not great for drag strip use but better than run flats. I would suggest running the front tires on the back for the strip to get an advantage in gearing.

Solofast

Most serious road racing and autocross tires aren't very good on the strip. The sidewall stiffness that makes them a good track tire compromises forward bite. Also, if you put in a good bit of rear negative camber and lower the car for autocross, that also hurts strip performance since it reduces weight transfer and angles the tire on the surface...

All that said, you might look into getting two cheap wheels and tires for the back, put a set of drag radials on them for strip work, and then a set of dedicated autocross tires and wheels. If you want to go to the strip with autocross tires look for ones with a softer sidewall, like the V710's and drop the pressures some, and get some (but not too much) heat into them. The Hooisers have a lot of sidewall stiffness and even at lower pressures aren't going to be that good on the strip..

cudadude

I'm already screwed with SCCA - first event with them three weeks ago and I'm in (N)ASP due to headers/intake. I'm not out to impress, however, just to have some fun.

The idea of a separate set of rears with drag tires might be workable - they'd have to be cheap rims however as this appears to be getting expensive (and I haven't even spent anything yet...).
Thanks for all of the replies...

cudadude

I'm already screwed with SCCA - first event with them three weeks ago and I'm in (N)ASP due to headers/intake. I'm not out to impress, however, just to have some fun.

The idea of a separate set of rears with drag tires might be workable - they'd have to be cheap rims however as this appears to be getting expensive (and I haven't even spent anything yet...).
Thanks for all of the replies...

vms4evr

Oh it doesn't appear to be expensive, it IS expensive.

Now if you went with the Nitto R2 setup that Joe_G mentioned. You could use the R2 for AX and HPDE. Then use their R (drag tire) for the strip on the rear. Basically the same tire but with softer sidewall.

I know how you feel on the ASP deal with SCCA. I have an oil cooler, which doesn't do diddly for AX. Right to ASP you go... Bad boy

Westwopper

Here is what I have on my c5.

Stock wagon wheels for the street with BFG KDW's.

OE Wheel Co's ZR1 reproductions with GS offset. BFG R1's on the way.

I don't drag, but if I did:

Get two more OE wheel co's ZR1 knock off's for the front, mount them on the rear and put 275/40R17's on the rear.

I'm sure there is a hotter set up then that.

Or just run your street tires. My KDW's hook up pretty hard on the street. I would bet I can get a 1.95 60' time.

DOT R tires for track use will suck on the strip. Maybe with a linelock, you can do a 45 second brake stand and get some heat into them, but I doubt even that will help.