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Thanks to JAM2 (Sir Blau) for the inspiration and Adrian at Glaswerks DMV for sourcing the wheels, who I highly recommend. IMO this is how the car should've come from Porsche as it pays perfect homage to the '89 G and 997.2 Speedsters. Wheels are 3 piece and setup is 20/21.
Looks like 315/30/21 rears - that's going to change gearing quite a bit (5%). If someone was inclined to have these PS 4S 21" tires without affecting gearing much, they make a 325/25/21 size (only 0.2" larger diameter than stock, rather than 1.3") - but not sure if that's too wide for the fender (depends on offset of the wheels). They also make a 305/25/21 (only 0.2" smaller diameter than stock - less than 1% difference)
Looks like 315/30/21 rears - that's going to change gearing quite a bit (5%). If someone was inclined to have these PS 4S 21" tires without affecting gearing much, they make a 325/25/21 size (only 0.2" larger diameter than stock, rather than 1.3") - but not sure if that's too wide for the fender (depends on offset of the wheels). They also make a 305/25/21 (only 0.2" smaller diameter than stock - less than 1% difference)
I agree - the wheel design looks sharp!
that big of a difference will result in the speedometer being off by approx 3 mph as I recall. Wheels do look good.
that big of a difference will result in the speedometer being off by approx 3 mph as I recall. Wheels do look good.
5% means it will indeed be off by 3mph at 60mph (or 5mph at 100mph or 10mph off at 200mph). But more importantly, it will make acceleration slower and make all the gears taller.
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Looks great @maineman Again @GrantG , I had the Porsche factory service rep there supervising the Installation of the wheels and same tires on my car. The gearing and speedometer difference was negligible. Actually, 1.5 mph given there’s already some fudge factor. He had no problems whatsoever with the tire size, and he is employed by PCNA. Apparently, the rennlist nannies have more issues with flexing their expertise on this EVERY SINGLE TIME. I will always defer to the PCNa factory service rep. Just let him enjoy his new toy.
5% means it will indeed be off by 3mph at 60mph (or 5mph at 100mph or 10mph off at 200mph). But more importantly, it will make acceleration slower and make all the gears taller.
i read it to be the difference to be 1.3 inches not %. My mistake.
So very happy with how these turned out! Welcome to the GlasWerks Family!
Thanks everyone for the nice comments. I was extremely happy with the way my car turned out, that is until I learned the gearing is off, my speedometer is messed up, and the acceleration is compromised. Next, I'll probably be getting a letter from PCNA that my warranty is void. Check the Rennlist Classifieds as these wheels will soon be listed for sale and my car retuned to stock.
Looks great @maineman Again @GrantG , I had the Porsche factory service rep there supervising the Installation of the wheels and same tires on my car. The gearing and speedometer difference was negligible.
I’m delighted that everyone is happy with the result. However, Ferry Porsche himself could have supervised the installation of the tires/wheels and it’s still going to gear the car 5% higher. Some may call this negligible - that’s a subjective call (I wouldn’t be comfortable with that, but I’m fine if others are).
I think I was wrong about the Speedo error - I think the modern Speedo is driven off the front wheels (the old cars use the rears). So, I apologize for that.
Not trying to spoil anyone’s fun - just want others considering alternate tire sizes for their GT3 to understand the numbers. Carry on...
05-11-2020 | 04:15 PM
Forgeline FUC3 "Fuchs Style" on Speedster
