LandShark

I'm wondering what kind of tire pressure do you guys run on the track? I believe the stock is 36/42 for street(?). But I've heard the Cup 2 doesn't like anything over 36psi?! What should I aim for hot psi at the track then??

Thanks in advance guys.

kfmcmahon

This is for MPSC1's , but same idea..I shoot for 32F/34R hot.
Beware starting cold pressures below 26 psi, because the TPMS in circuit mode does some weird stuff if the psi starts below 26?!?!?!?!?!?!

https://www.tirerack.com/tires/tiret...nd_Feeding.pdf

LandShark

yeah, read that. That's why I asked should I run them <36psi hot as recommended (btw, those were for the Cup 1), or sticks closer to the Porsche's recommendation (36/42hot)?

If I go for the Michelin, it will be more like 4-6psi lower than what Porsche recommended, and will it be OK for the track (safety-wise)? And would I be running over to the (tire's) shoulder, like go over the sidewall mark?

Car is in stock suspension setup BTW (camber, toe, everything else).

Thanks again.

kfmcmahon

you would be sliding all over the place at 36/42!

If you are worried about too low a starting pressure, then start at 28-30 and build up speed/heat until you feel the tires getting "greasy"...note that pressure and hot-pit and adjust down to the pressure where the tires grip felt best...trial-and-error kind of thing.

best to use a pyrometer if possible...the Michelin pdf has fine tuning point on tire tread temps (better measure than pressure) across the width of the tread

mwar99

Isn't that too high even for the street. I use 30/33 starting on the street. It goes up from there. I try to keep 30/32 on track hot if possible.

loopsandsounds

With a long session (say 20 minutes or more) you'll see over 42 at the rear regardless of starting pressures. This is why the side muffler bypass is so important for folks that regularly track their cars as it significantly reduces heat and hence tire pressures on the rear. I found a consistent reduction of 6-7 lbs on the rear tires for a 20 minute session. Now if you are overcooking the fronts then you aren't using enough throttle...

TRAKCAR

Cold PSI innthe door is often a good indicator for hot temps on the track.

MPSC2 like to be 30-32 hot.

This means starting 22-24 on a cold day..
So to be a bit on the safe side and to keep the TPMS happy, start at 26 and bleed down to 32 after a few laps.

SmokinGTS

delete

SmokinGTS

^^ Trackcar has it right.....

bccars

I've read on the Michelin website optimal grip between 33-36 psi hot for the sportcup2 ...

levd

28 psi HOT both front and back works best for me on track. 30 psi is still fine, but more than 30 is no good for both tyre wear and grip.

LandShark

So front and back about the same tire pressure too, +/-2? (seems like that's what most of your recommended)

Thanks again guys!

levd

All 4 corners the same pressure.

RFGGT3

+1

Forestek

Got this file from Michelin with the latest recommendations in pressures.
Seems higher than what most of us are running. I run around 30psi Hot on 4 tires