I have driven my F-Type a few times at the race track during HPDE days, and a friend mentioned tire heat cycles. What exactly is that, and how do you know when the tires are ‘cooked’?
Those are complete cycles, from cold to hot, then back, a tire makes.
Street tires dont get “cooked,” per se… they just get tread ripped off of them. Any tire having been overheated, will show blistering, so inspect your tires for that.
Racing tires, having a completely different chemical makeup, is where the heat cycles make a difference. More heat cycles, on a slick, generally results on a hardening of the tread compound.
It’s also likely that street tires don’t get as hot as race tires, excluding track days.
In a single day, a race tire might see ambient to +170 degrees 4-5 times, for 20-30min at a stretch. They are literally getting cooked. Over a season this adds up.
Generally, that is correct: even in classes where street tires were used–as they were in the IT or SS classes at SCCA–street tires were shaved into what amounted to slicks.
I could get 4 races out of then. No such deal for slicks: one and done!
Thanks for the feedback. I’ve already gone thru two sets of P-Zeros, and now wearing Mich. PS4S. I’ve been on the track a couple of times with these newer Michelins now. The first day, I noticed the metal balance weights fell off the left front wheel, and had to get that tire rebalanced that evening. That’s when I found out how hot the wheels/tires can get, and what that silver tape is for. Anyway, I was out again last Jan., and this was when the subject of heat cycling came up. Is there any physical way to tell if my ‘street’ tires have been over cooked, and time to get another set? Thx. Glen…
Are you shaving the tires before hitting the track? They’ll handle better and last longer if you do.
Nope. I’m not that far into racing. I just like to go as fast as I can at times. Better the track than the local roads. So, I drive to and from the track (2 ½ hours each way) on the same tires I go to the store. I just want to be sure those tires are still safe to ride on.
If they are not blistered, they are safe.
Pro tip: you clearly love tracking the car… do yourself a favor. Get a spare set of rims, get some serious track tires, like the DoT Hoosiers.
The improvement in stick and handling will be dramatic.