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GaryR GaryR is offline
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Join Date: Mar 2005
Location: Valencia, Spain
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Originally Posted by KTL View Post
Tire usage/choice is unfortunately often driven by availability. If people ain’t buying a tire size/diameter, tire makers don’t make them. Just that simple. So it leaves us to seek out another size

That said, I respectfully disagree with Kent’s assessment in saying the suspension doesn’t work “at all” with tire diameters different from those sizes original to the car. The wheel sizes for the earliest cars were sized around the size of the brakes- you need a wheel big enough to clear the brakes and not much more than that. Plus, tire construction and materials have changed a ton since the 911 was first designed

My own experience with the suspension working has been good. My ‘79 car running 17” wheels was able to perform very well against good drivers with newer 993 cars running 18” tires. However there’s also guys running 15” Hoosiers in PCA stock class that are very fast cars. Those 15s run shorter sidewalls (275/35 rears) that bring down the ride height and also establish a higher effective gear ratio for faster acceleration due to greater torque multiplication. So it’s not as easy as saying these cars were designed for 14” & 15” wheels and anything else is less than optimum
Agree with Kevin, my experience is 95% track use (DE and Racing) and we started out with 31/24 TB's and 275/35 245/40 18's on our PCA Stock D SC's. We went to the max size TBs (35mm IIRC in the rear) and 275/35 15's and with the gearing advantage dropped track records across the board. The system worked well, as long as we kept the suspension movement and didn't lower the car too much all was well...
Gary R.
Old 02-17-2019, 02:22 PM
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