How badly will street driving compromise the maximum number of R comp heat cycles?
11-01-2003, 03:59 AM
#16
Instructor
Join Date: Aug 2001
Location: Agoura, CA
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I have been driving my p-cars on DOT-R tires on the street for about 6 years now, mainly Yoko A008RS's and Kumho V700's. I was surprised by how many street miles could be accomplished on top of multiple track events with decent performance. Until earlier this year I drove to the track on those tires, too. I do however keep separate wheels with Hoosiers for the more "serious" track events. Those tires do not see any public roads, and now the car is trailered so I keep 2 sets of wheels with Hoosiers and 1 set with something a little more durable/streetable for canyon fun runs and such.
As the other guys said, I think tire temps in street driving are probably on the order of 60-80° less than what is considered optimal on the track.
As the other guys said, I think tire temps in street driving are probably on the order of 60-80° less than what is considered optimal on the track.
11-01-2003, 09:59 AM
#17
Kim
I drive to the track on MPSC's and have accumulated over 3K street miles (some of the tracks are a long way from home ;-)) and 55 heat cycles before they lost grip - although they still had tread. I know one driver who has over 60+ cycles and the MPSC's are still ok.
Tire pressure for MPSC has been discussed on this board before, but I now know that MPSC are VERY sensitive to inflation pressure, and I suspect that this will also effect wear as well as grip. For rear heavy 911's the target setup is 2-3 psi difference front to rear (higher in the rear) and median pressure about 33 psi HOT. Changes of ONE psi can make a noticeable difference so take that into account when tuning your setup. Pressure recommendations came from a Michelin engineer and were independantly confirmed at other events with other Michelin engineers.
Dave
I drive to the track on MPSC's and have accumulated over 3K street miles (some of the tracks are a long way from home ;-)) and 55 heat cycles before they lost grip - although they still had tread. I know one driver who has over 60+ cycles and the MPSC's are still ok.
Tire pressure for MPSC has been discussed on this board before, but I now know that MPSC are VERY sensitive to inflation pressure, and I suspect that this will also effect wear as well as grip. For rear heavy 911's the target setup is 2-3 psi difference front to rear (higher in the rear) and median pressure about 33 psi HOT. Changes of ONE psi can make a noticeable difference so take that into account when tuning your setup. Pressure recommendations came from a Michelin engineer and were independantly confirmed at other events with other Michelin engineers.
Dave
