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fredmeister fredmeister is offline
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Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,232
Michelin Pilot Sport tire pressures

Thought I would post on this forum as well as Racing Autocross Forum;

Hey, was hoping to get some info on actual cold inflation pressures for my Michelin Pilot Sport Track tires.
Took them out on my 79 930 turbo for the first time and am having hell of a time getting any front grip. The car understeers horribly, even after 5-6 laps on a real twisty course, Gingerman Raceway in Michigan.
Tire sizes are 255 rear and 225 up front, so the sizing balance is pretty normal in keeping with Porsche 911 practice of having more/wider rubber on the rear.
Measured tire pressures after 5-6 laps on the rears were 39-40psi which sounds about right, but the fronts were 33-35psi which seems low in comparison to the rear tire pressures which had lots of grip.
Can anyone supply the cold pressures they use on these tires for a 911/930?
What hot running temps should I see as well, is 40psi correct?

1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 04-25-2008, 02:42 PM
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