jenk12m

i'll have to check my settings but that was all normal street driving

CorsicanBB

I have 7,000 km(about 4,400 miiles on mine) and they still have good thread left. That's highway miles + 1 track day and a lot of aggressive driving. I am running the Porsche standard street alignment.

I have a question for you guys: what do you mean by heat cycles? And how do you figure out how many you have on your tires?

amaist

You have to remember to distinguish between Michelin Pilot Sport Cup and "Michelin Pilot Sport Cup N0" tires. The "PSCs" that come stock on 997 GT3s are not the same as the ones people buy elsewhere. They have deeper and wider grooves and a harder compound. The normal PSCs gets killed by head cycles but the exact number can vary from batch to batch and by driver. Some people say they are junk after 24 cycles some keep driving until they get corded.
How long they last will depend on alignment and the proportion of track use. The famous Kusmaul (probably spelled wrong) alignment is a great compromise between street and track and the insides of the rear tires don't get corded as fast. But I started cording the outsides as I got more familiar with the car as I barely use it on the street.
For an intermediate driver I can guess that they can do 10-15 track days (PCA DE days). But if you go faster then it's all about how much you can afford to spend on tires.

A heat cycle is when your tires reach their max operating temperature (or close to it) and cool down to close to ambient temperature. A single track session can be considered a heat cycle.

OldGuy

Heat cycles are how many time you have brought your tires up to operating temps on a track. I think street driving would have to be awul aggressive to count as a heat cycle. Some race tires can wear out of heat cycles before the rubber is gone. One heat cycle would be one session on the track, heating up for the whole session and then a cooling off period before you go back on the track for another session. The real racing boys will clarify.

blake

A "Heat Cycle" is when a tire heats up to operating temperature, then cools down to ambiant temperature. The term mainly applied to track driving as road driving seldom gets the tires up to optimal temperature. These "optimal tempertures" make the tire very sticky and soft, and really help keep the car planted against lateral forces.

I attend Driver's Education track events under which I will have six 25 minute sessions on the track. Each of these sessions would provide a complete "heat cycle" as the tires would go back to ambiant temperature between sessions. Michelin Pilot Sport Cups tend to get "hard" after about 24 heat cycles. This means that they do not soften up once the tires get to optimal temperature on the track, and the tire "stickiness" goes down hill fast. Let's just say sliding around the track becomes the norm...

-Blake

jenk12m

what actual camber/toe numbers would be good for saving the inside of the tires from cording up

mooty

well, it depends on how you drive and where you drive.
right now with 3 deg of camber, and MY combined use of track/street, i wear inside slightly quicker the inside due to street use. if i didn't use it on street, i would get even wear at my speed. if you are faster, then maybe more camber. if you use it on street more you may need less toe and less camber. there is no magic alignment number. you have to trial and error.

jenk12m

thanks mooty

C.J. Ichiban

my track is pretty low speed with a few too many tight radius turns, I ended up wearing out the tread on the outside of the front tires before cording the insides...3700 miles including 5 full track days

ScottL

another point with the Cups (both the original and N0 versions) - they don't work so well below 8 degrees. Wear rates increase rapidly.

mooty

low speed tight turns. so your car probably pushes badly too right?
try a lot more camber up front, then play with bars.

C.J. Ichiban

mooty I'm getting the new GMG blade sway bars installed while I'm away. pushing isn't alignment related on my car- it's from going too fast on entry, or trying to gas too early. when I try to overpower the entry, it scrubs. when I apex correctly or even overpower the exits- it's sublime

mooty

ah, i see, you are impatient like me.
SLOW in fast out.
but no.... i fast in, f'up, and spin out.

jenk12m

LOL

Crazy Canuck

Mooty, have you tried them on a 996 GT3? I see the R888 comes in the right sizes.