Pressure for track use?

[Matt Fojtik]

Hello,
I am having my first trackday on Monday and am wondering what pressure to run. I’m on 19/245/35f and 19/265/35r Michelin Pilot Super Sport, so OEM setup.

Thanks!

[chocolate.s65]

It will depend on the track and how loaded the car is. Are you measuring in PSI or Bar? 2.3 front and 2.4 bar rear for 2pax + small load. Run 2 bar/29PSI front and 1.9bar/27PSI Rear as a start and do a few laps or a session. When you come back in re-measure and see what PSI / pressure is in the tyres when warmed. You might notice differences across all but bleed them back to what you should run stock.

[DRLane]

Originally Posted by Matt Fojtik

Hello,
I am having my first trackday on Monday and am wondering what pressure to run. I’m on 19/245/35f and 19/265/35r Michelin Pilot Super Sport, so OEM setup.

Thanks!

I’d shoot for 36-38 PSI hot on PSS. I wouldnt go under 30s cold given it’s your first day and it’s unnecessary for street tires.

Just go out for the first session as is from arrival and bleed the air out when you’re back in the pits down to 36. Rinse and repeat. Note depending on the weather you’ll likely do this a couple times.

Might be worth bringing a compressor if the track doesn’t have one for public use to bring the tires back up for your drive home.

Don’t overthink this part, focus on trying to learn the track, look ahead, and conscientiously wave at the corner workers to broaden your vision.

[DrFerry]

Originally Posted by Matt Fojtik

Hello,
I am having my first trackday on Monday and am wondering what pressure to run. I’m on 19/245/35f and 19/265/35r Michelin Pilot Super Sport, so OEM setup.

Thanks!

With Michelin PSS ideally you're looking for a hot pressure at the end of 20 to 30 minute session of ~38 to 40psi at both ends of the car on a 3650lb E9X M3 plus a driver and half a tank of gas. Depending upon how hard you're capable of driving the car, the ambient temperature(s), and your negative camber alignment settings, the cold to hot pressure gain will be approximately 4 to 6psi. So given a hot pressure ceiling of no more than 40psi, your cold pressure starting point should be 34 to 36psi. Again, all of this is assuming Michelin PSS.

You may see a split pressure condition where the fronts are a couple of psi higher than the rears -> IF driving at the understeer limit only. IF driving at the oversteer limit - and sliding the rear axle - then the rear axle pressures may be slightly higher than the fronts. The Michelin PSS tread compounds provide their best hot regime grip when operating within the ~160F to 190F range. Use a pyrometer to take hot tread temperatures. You'll know if you're getting the tires decently hot because they'll be almost scalding to the touch when measured after immediately pitting at the end of the session.

Edit:
The Tire Talk Mega Thread
https://www.m3post.com/forums/showthread.php?t=1916791

[omgzirra_exe]

full weight = 40-42psi on the last lap... right before session ends. especially on PSS even PS4S

[Matt Fojtik]

Thanks for the help everyone!!