sleeper02Z06

A6's have somewhat of a bad reputation for not lasting and that is simply not true. I have gotten 12+ heat cycles ( 2 45 minute races and the rest 20 minute test sessions ) out of A6's. I usually flip them on the rim at around 6 cycles. They slow with heat cycles but every tire does and I can tell you first hand they are faster heat cycle per heat cycle against any other tire I've been on, period. Kumhos last longer but in my experience it is only because they have very thick tread. For me, even though they were not gone a Kumho after it's 12th track heat cycle was worthless anyway. For HPDE's, give A6's a try at least once to feel just how fast a tire can be, but the rest of the time look for something you can get more out of for the money. Also, as blur was saying, driving style has a lot to do with it. Driving at 8/10th's with a properly setup car I'd put money on 20 cycles from A6's.

Joe

Sidney004

285/30's; 315/30's; I think the rim width will determine the max tire size.

kermooni

Depending on where in Sioux Falls you start from, It is approx 440 miles. Averaging 73.3 MPH (excluding stops). I am sure your Z06 will make up for the stops

See you there. Do you run at BIR also? With Bimmer club? PCA?

There are two events coming up in late Sept and Early Oct. See if you can make it.

Best.

dvandentop

you are going to the september 6 event at RA right?

also i have never been to BIR that is quite the trek usually go to mam in omaha alot closer and the pavement doesnt tear up tires too bad

kermooni

Thanks Joe,

My main concern which I did a poor job of getting accross, is rubber compound and its effectiveness in Midwest weather. We do not have track temps anywhere near the folks south of us - especially in spring and fall. I was hoping that A6's were softer and hence more usable in cooler temps. Please realize that I have gone from outside window frost at 6am to 85F temps by 1:30pm. I would not run the slicks in the morning, but for mid-day sessions they would be on.
I have considered the R1 / R888 very strongly, but am not sure I want to hold on to them for as long as they last. If the slicks last the three weekends I have coming up, I would be quite happy.

Best.

EvilBoffin

I have the exact same C10 wheels & sizes on my C6. Nice choice!!

Currently I'm using 275-35 / 305-35 Toyo RA1's, and there's plenty of clearance for more width thanks to the CCW's optimum offset. The wheels can certainly handle wider rubber, too.

So 315's would be great out back, 285's or 295's up front. 315's may also fit in front, but they might feel a little sloppy on turn-in (depending on your driving style & alignment, of course).

It's worth mentioning that 285-30 and 295-30 Hoosiers are actually the SAME width (within .1 inch). The only notable differences are diameter and load rating.

FYI - I just mounted a pair of 295 A6's on OEM front 18x8.5 wheels for autocross use. They fit just fine, even mounted on these stock-offset wheels. I can post some pics if you'd like to see them on the car.
.

ScaryFast

Seems we're splitting hairs, here. I can tell you with high confidence that these tires (A6 or R6) with many heat cycles will NOT be as fast as a new(er) set of the same tires. Yes, there's tread on them. But the compound of the tire has changed and they are harder. That's why race teams that can afford to do so throw them away after three or four sessions. Argue all you want about how they can be run for a whole season.

That said, for HPDE, where lap times vary 3 seconds a lap due to driver and traffic, this is irrelevant. An A6 = R6 = V710 = Nitto = Toyo. Run them until they cord.

rhneff

Hoosier makes the A6 and R6 in the same sizes. I run 315/30-18F and 335/30-18R on those wheels, but make sure you get the offsets just right or, depending on your setup, you will get rubbing on the inner fender liners and may get slight rubbing even so.

Kumho V710 is problematic because they don't make the 315 in a 30 series sidewall and the 35 series is too tall in that size for the front unless you're willing to risk your fenders. Unfortunate, because as someone previously mentioned the V710 is the perfect HPDE tire - nearly as grippy as the A6 and lasts at least as long as the R6 or longer.

Another alternative, especially if you want to consider driving to the track in the Vette, is the Toyo R888. It's less grippy than any of the above but not that far off the R6, has enough tread to serve as a rain tire or occasional (as in to the track and back) street tire, and in my experience provides terrific wear/longevity. Another positive is that it tolerates a bigger slip angle than the Hoosier or Kumho and gives you more warning as it approaches the edge of losing grip, so it's more forgiving and easier to drive for the weekend/non-pro driver. And it's available in the same sizes as the Hoosiers. It is more expensive, the the extended life actually makes it more cost effective for HPDE use.

kermooni

I had a long conversation with an engineer at Hoosier.

Many for him/Hoosier.

He listened to everything I said, answered all my questions about their tires and compounds and ... asked a bunch of questions about me, my experience, my car, the track(s) and finally recommended the R6s. He said they last longer and compared to A6s provide little if any measurable difference in my lap times. So that is what I am getting.

Will let you know how everything goes.

Thanks.

kermooni

Right. I do not know about MAM. It is too far for me in Omaha - maybe.

There is a new track in Iowa the Northstar Bimmer boys loved. I will go to it next year. Interested?

See you at RA

EvilBoffin

OK, what SIZE R6's did he recommend you get?

(obviously this is wheel-size related, but I wanna know what a Hoosier insider would recommend for tracking a non-Z C6).

dvandentop

what is the name of the track in iowa?

i really wish the plans would come together for the track in worthington MN would come along as they are at a standstill now

kermooni

No discussion on sizes ... I did not ask and he did not recommend. Give them a call, very nice people to talk to.

gkmccready

I have C140s in 18x11+18x11. You need to run a bunch (-2.0deg) of negative camber up front. Toyo R888s 295 front, 305 rear. I'm supposed to try 18x12 rears and see if they tuck into the fenders.

18x11 up front means you will want steering rack travel limiters, though, or you will hit the inside of the wheel wells, or if you're running too little camber you will hit the tie-rod.

The guys at CCW are EXCELLENT to work with. I don't think I'll ever buys wheels anywhere else ever again.