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Howard Jones · 11-26-07, 03:11 PM

My advice is if you are thinking about a second set of wheels for track use, you should at least consider 17" wheels. The number of tires avaiable in 17" is too long to list. Many can be bought for 1/2 the cost of equal peformance 15" tires per set.

The look of 15" or 17" wheels is what it is, but if you intend to run on track then I think that performance bang for your buck is much greater with 17 inch wheels. Some of the Z rated summer only max performance tires are really very good trackday tires.

I run my 17" 245.40.17 F and 315.35.17 R at 26psi F and 27psi R as a starting point pressure. I usually see at least 3-5 psi increase on a warm day. warm = 80F - 90F air temp
and have seen 6-7 psi increase on hot day +90F AT.

Oh and I agree on the 15" BFG's. Be very careful with these on track. They will really get slick (read no grip) when they get hot. On a hot day they go off in about three laps. Just about the time it takes for you to feel good about going for it.

11-26-07, 03:11 PM	#5 (permalink)
Howard Jones 10 tenths Join Date: Jun 2002 GT40: San Francisco Bay Area California USA Posts: 1,884 Rep Power: 25	Re: tire pressures My advice is if you are thinking about a second set of wheels for track use, you should at least consider 17" wheels. The number of tires avaiable in 17" is too long to list. Many can be bought for 1/2 the cost of equal peformance 15" tires per set. The look of 15" or 17" wheels is what it is, but if you intend to run on track then I think that performance bang for your buck is much greater with 17 inch wheels. Some of the Z rated summer only max performance tires are really very good trackday tires. I run my 17" 245.40.17 F and 315.35.17 R at 26psi F and 27psi R as a starting point pressure. I usually see at least 3-5 psi increase on a warm day. warm = 80F - 90F air temp and have seen 6-7 psi increase on hot day +90F AT. Oh and I agree on the 15" BFG's. Be very careful with these on track. They will really get slick (read no grip) when they get hot. On a hot day they go off in about three laps. Just about the time it takes for you to feel good about going for it.