LandShark

Hi all,

Sorry if this topic had discussed before. I have a 14' stock 991S, sport suspension, running factory PZero, white group driver. I'm wondering what kind of cold pressure and hot pressure should I shoot for at the track? I was running as high as 36F/44R, even tho it sounds high, it feels pretty good at the track. But I want to see what others recommended? Am I running too high? Factory full load, comfort setting, is about 36F/42R I think....

Thanks in advance guys.

ClarkGriswold

I just did a HPDE recently and was running at or higher than your 36/44 hot, more like 39/46 hot. I talked with several folks and dropped the psi significantly during the day (as the track and ambient temp rose) to like 27/30 cold which resulted in hot at like 32/36. Much much better results. 40's are too high, tires were getting mushy (edit-better description is feeling "greasy").

This was a 2012 911s on P-zero's, temps were 72 at 8am and rose to 88 or so in afternoon.

JayG

The higher the pressure, the stiffer the tire will be, so I don't know how higher pressure would make the tire mushy

ClarkGriswold

Sorry, poor word choice. Maybe a better description is "greasy". The tires just aren't gripping well and are overheated.