Newbie Tire Question....what do ya'll mean by HEAT CYCLES?

[ulev1st]

I am new to NASA and Track Days...I totally ruined a brand new tire my first event..(this can get expensisve I see!) anyway..someone asked me how many heat cycles I had on the tire...of course I gave him that "deer in the headlights look"....as I didn't have a clue what he was talking about..

Can someone explain what it is and how it helps or why it is important?

Thanks for your patience for answering a "newbie question".

Don, newbie to NASA MidSouth.

[kbrew8991]

heat cycles = how many times the tire has been brought to operating temps and then allowed to cool back down

 

Rubber is a funny material, doubly so the stuff in performance tires, so nothing is set in stone BUT generally as a tire has more heat cycles it gets harder and has less overall grip.

 

The number of cycles is important, but also what kind of heat cycle it was matters a bit, as well as what car it was run on (weight, suspension design & setup, etc) and a bunch of other factors. And certain tire makes / models will drop off in grip at lower number of heat cycles than others

 

Confused yet?

[krystar]

what kind of tires are u running? if it's a street tire, you must have been pushing alot to ruin a brand new set of tires in one weekend.

 

basically 1 heat cycle = 1 track session.

[kbrew8991]

based on posts I've seen about the event the surface at that track is unusually abrasive. That coupled with a car that might not be setup perfect, a driver that's still learning, or many other factors along those lines I could see wiping out a tire prematurely

[Light on Fuel]

Not to jack the OP's thread, but;

 

What would be a good tire for a noob on a first outing? These tires would need to transport me to and from the track, however, the car isn't used as a daily.

 

Thanks.

[n80]

Manny, from one noob to another I can tell you what a lot of people have told me and what my experience was. This relates to the OP as well.

 

Anyway, most everyone says to learn on street tires. They tend to let you know where the limit of traction is so you learn your car and the track better while track tires tend to hold grip much better but when they go, they go suddenly.

 

I did my first track day on Hankook v12 Evo tires. These are a high performance summer tire but have a slightly harder compound than other high performance summer tires. I selected them almost purely based on price. They're cheap, they have good wet traction and good behavior around town and should last longer than the softer tires....probably at the expense of performance.

 

Anyway, for me they worked out quite well. Even in my heavy car they gave good feedback. First with a little squealling, then louder squealing and when they did lose traction it seemed to be incremental and not all at once. I only got sideways once (gators) and got back straight without too much drama.

 

As far as wear, well, it was pretty dramatic. These had only about 1500 miles on them. After track time there would be places on the front where thin bits of rubber where shredded and sometimes balled up on the tread. There was also some feathering on the outside edges (on the street my car usually causes feathering on the inside edge). Anyway, after each session the tires would look terrible. But, after a few hundred miles on the street they look pretty much back to normal without as much tread loss as I was fearing.

 

I think any fairly soft high performance summer tire would be reasonable to start with. Again, I'm a noob too so take it for what its worth.

[getfast]

As far as wear, well, it was pretty dramatic. These had only about 1500 miles on them. After track time there would be places on the front where thin bits of rubber where shredded and sometimes balled up on the tread. There was also some feathering on the outside edges (on the street my car usually causes feathering on the inside edge). Anyway, after each session the tires would look terrible. But, after a few hundred miles on the street they look pretty much back to normal without as much tread loss as I was fearing.

 

The rubbery bits you saw were pickup from the tires of others... on the track, on pit road, and in the paddock. You may have similar "worms" inside your wheels as well.

 

Feathering on the outside edges = wrong pressures and/or not enough negative camber and/or overdriving and/or too much understeer. Pretty common for street cars at the track... especially on the outside front tire.

[philstireservice]

One of the biggest mistakes that people ( noobs and experienced) make with street tires is that they start the tire pressure way too low !!!

 

Remember this if you remember anything about tires -

 

Street tires don't like heat. Tire manufacturers build street tires to resist heat so they last longer.

 

Race tires/track tires (R compounds, i.e. Hoosiers, RA-1's, Z214's, BFG R1, etc. and some wanna be R compounds, i.e. RS3's, Star Specs, R1R's etc) like heat or should I say need a certain amount of heat to operate well.

 

So with the above info - Street tires should end up in the 47-48psi range - hot. These are not starting pressures but ending pressures after a session on the track. Don't start the tire pressures below what is on the door sticker ....EVER !!!

 

Don't worry novice guys and gals, most "experienced" track guys and gals start their tire pressures too low also........my pet peeve..