I know that the Kumho Victoracers have a bad reputation for being sensitive to heat cycles, but I don't really know any details. How many heat cycles does it take before they go bad? What exactly constitutes a heat cycle? If I drive to / from an autocross (on my race tires) where I do 4 consecutive laps (separated by only 30 seconds at grid each) in the morning, and 4 consecutive laps in the afternoon, would that be 1, 4, or 10 heat cycles?

I'm trying to figure out if I am making a mistake by driving to and from the events on my race tires.

I am also curious how many events (or runs) the average S2000 owner is getting out of a set of Victoracers. The events I go to are pretty long and fast (80~100 secs at as much as 100 mph), and we get at least 8 runs per event. Is it possible that I could get 6~10 events (50~80 runs) out of these? I know that there are a TON of other factors, but I'm just looking for an average. For comparison, I got 6 or 7 events (and 7500 miles) out of my original S-02s.

 

Not sure the exact definition of a heat cycle, but I think of it as every time the tire is brought from room temp up to operating temp and back down. So to answer your original question, I'd say as high as 4, but maybe as low as 2 if your runs were at the very beginning and end of the day. In any case I don't think you can tally heat cycles up and come up with any meaningful good/bad crossover point.

Those are some pretty serious autocross courses you have there in Plano - 100mph? Running in San Diego and LA my Kumhos lasted me about 80-100 runs, each run being about 1 mile and top speeds around 70. I think 50-80 runs is an accurate estimate of how long your tires will last, provided they're all done within about a 6 month window. The clock starts ticking when the tires are first used, and after about 6 months they really start to suck. Street wear is almost nil compared to racing, so as long as the autocross venue isn't too far away, driving them there should be just fine.

Have fun!

 

They're done at what used to be a military helicopter base. Basically, a 1/4 mile by 1/4 mile flat square. So it's possible to set up a nice 1.1 mile road course that'll let an S2000 go over 100. Z06s and 911TTs usually go above that. Typical format is a warmup lap followed by four timed hot laps. Lots of fun.

 

That's the format that the Porshe club uses for their time trials. I went to one a couple weeks ago, and glazed the HELL out of my brake pads. I don't think I like that format with a basically stock car. I almost rear ended someone at a stop light on the way home. It has been over a week, and my brakes still haven't gotten back to normal.

 

[QUOTE]Originally posted by jzr
[B]The clock starts ticking when the tires are first used, and after about 6 months they really start to suck.