[Ron Sutton]

Originally Posted by Panteracer

I am wondering about running the A6's (autocross tires)
on the race track.. it was always my understanding that
they heated up quicker but will not sustain the longer runs
of heat required by the race track and 20 minute sessions

Heat cycling always help the tire last longer but not sure
if that type of heat cycling will work... I do understand
that race slicks have several compounds from soft to hard
just wondering about the A6's??

Ron or anyone had any experience with them

Panteracer Norcal Bob

Was hoping to be going to Optima in Oregon that weekend

Originally Posted by GregWeld

WE are trying the A6 because of the tire temp measurements of the R6's when running Thunderhill.

We ARE not racing.... and I'm certainly no race car driver.... a real race car driver would most certainly generate too much heat... but I don't. I also have a complete set of R6's mounted on another set of wheels -- so if the temps tells us the A6 is getting too hot... a simple switch will be made. WE are doing this based on the science of our own measurements, rather than, what someone told someone else's buddy one time.

The tire pressures I WAS using were near but not close enough... actual measurements of the tire temps and ending pressures etc gave us the info needed to set the tires right. Now - that's the new numbers being used instead of just kinda sorta someone else is using X pressure.

I have quite a bit of experience running and/or testing most of the Hoosier tire line. In addition to being a great autocross tire, the A6's are a great track tire as long as you don't over heat them. And by overheat them I mean run them at 230°+ for several laps. That would shorten their life considerably.

What I saw at the track was ... by the end of the weekend ... Greg was driving the hot rod at 90-95% ... braking moderately ... being smooth with the throttle, braking & steering ... which all keeps the tires happy ... and cooler. As he pushed the car harder & ran those 2.08-2.10 lap times, the tires came back in the mid-to-high 160° range.

Another part of the reason for cooler temps is the track sessions are short ... 20 minutes ... about 9 laps. Frankly, it takes a couple laps for the R6's to really come in. So for 2 of the 9 laps you need to be more conservative.

Greg will have better braking on the car for Sonoma, so the rotor temps coming up will also increase the tire temps. I think that plus the softer compound will put us 20-30° higher temps with the A6's ... putting them in the 180-190° range ... which is right in their sweet spot. And these tires will warm up quicker & provide grip the driver can be confident in MUCH earlier in a session.

Greg's goal is to have more fun. IMHO, if you tow your hot rod all the way to the track and run 4 sessions of 9 laps ... 36 laps ... and we can make 8 of those laps more fun (with more grip) ... that achieves the goal. The A6's will wear quicker than R6's, but when you factor in all the cost to go run a track day, it's minor compared to having 22% more "fun."

That's the reason I suggested A6's for Greg's Hot Rod.