BrntRubber

awew911

Check your tire pressures (not using TPMS). Just ran at Sebring in the cool Florida weather with the Cup 2s. Do they behave differently on hot track / cold track? Yes. The tire pressures may climb so keep an eye out on those.

991carreradriver

I had the same experience two weeks ago. Ambient temps were high 90's and track temps were in the 125-135 range. Tire pressures were carefully monitored and the tires gave up on the second day. They simply melted and became like grease. Since these SC2's only have about 350 miles on them and 24 cycles, I will give them one more event, hopefully in cooler temps. This is not the first time this has happened to me with SC2's.

Dougr743

If you consistently have too high of tire pressure increase, you have the tires too low when starting. low pressure will increase heat. In a perfect world you would want to have aprox 4 to 6 pounds of increase at full temp (or up to speed) as soon as you come off you hot lap. If they have increased way past this average, add air, yes add air, that will lower temp and keep the tire from failing (until the tire is totally wiped out) this is the tire warmer reason. Setting the tires to race temp prior to the race, then adding or removing air as needed. I see guys running too low of pressure on the street a lot and baking the tire. Same as on the track. If you run 30lbs and you are coming in at 40 you need more pressure, visa versa, if you go out on 35 and come in at 35, you need to drop pressure, as you get faster, or push harder, you should see a change in the tire pressure, but not by more than a lbs or 2

BrntRubber

BrntRubber

Nagata-San

Way too much pressure.

Use them 2.0 and 2.2 on normal track and 2.2 + 2.4 on bumpy tracks (Nordschleife - Sebring).

Dougr743

how much pressure are you gaining when pushing the car? Every climate, track, road, and car weight will affect it. I would check them prior to running hard, then adjust as needed. there is no standard setting. just because i run more or less, does not mean you should. it totally depends on operating temp cold and hot, then adjust. hope this helps. get a really good temp gauge and start from there. I use the same process that i used racing motorcycles. all processes are the same, the tire and the car will tell you if you are too high or too low

WenigerAberBeser

TRAKCAR

BrntRubber

cox1974

I'm in southern Italy.... My hot tyre pressure on the street is max 2.2 / 2.4...sportmaxx race 2

FourT6and2

My car (on the street) has 33psi front and 36psi rear when cold. The other day I was out on a long, spirited drive on a hot day. Pressure go up to 38 front and 41 rear. Measured with TPMS. Definitely felt like the car was losing grip. Should I add or remove air in a case like this?

zedcat

For the street, I always set to Porsche's recommended cold pressure (on the door jamb label) 29psi front, 33psi rear before driving. Typically see max of 36 rear. 38 to 41 will likely feel greasy and I would bleed a few psi if they got to the 40 range.

For the track I like 32 front 34 rear hot, so depending on the conditions I'll start first run at about 27- 28 and adjust from there. Michelin recommend for track 33 to 36 hot and beginning at 24 to 26 cold (but never below 22 due to risk of structural damage. My experience is 991.1 GT3 and N0.

TRAKCAR

For me cold is 27-27, I don't want the idiot light to come on below 26 if I forget to confirm circuit mode.
They come up quick enough on the street to get to the ideal street pressure (for me 29-31) and they will go higher still.

Just no need to start too low on street to get to the ideal track pressure.
This is in swamp country Florida so lots of humid air in the tires, we see bigger increases. Nitrogen will reduce.

Wet air @ Sebring you'd have to start below 20PSI and it takes 2 laps to get carefully to 26 staying off the big bumps and corner slowly.