-=RX-7 KID=-

Me and a few og my friends were debating over which wheel size would be better to run for drag. I have 17 inch enkie racing wheels, they were sayin that they like 15 inch wheels over 17. The only thing i could figure that would make a 15 better for raing would be that it is lighter. Am i wrong? They were sayin the 15's turn faster giving yoiu better times but that didnt make any sense to me because your 17 inch wheels just have more rubber to turn even if it's not as fast it all equals out in the end. So what do you guys say?



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rx-7addict

When you're talking weight of wheels the more important part is the distribution of mass. IT's physics I forget the formula exactly but the placement of the mass and distribution all affect the centripital (sp? it's been a while since i read my physics book) acceleration. Anyway so all these people that base what wheel to get upon the pure weight forget about that. A 15 inch wheel with very little weight that's evenly distributed will be easier to start moving if you compare it to a 17" wheel that weighs more and has the same weight distribution. That's the key factor in the comparison....

rx-7addict

guess I really didn't answer your question full out basically you can't generalize it based upon what you were saying there are other major factors that come into play

1988RedT2

The Outside Diameter ( O.D. ) of the tire is the key factor. Running a smaller than stock diameter tire is like putting a lower (numerically higher) gear in the rear end. The smaller tire will give you better acceleration, with the trade-off being a lower top end.

1988RedT2

See also this post from earlier:

QUOTE (Dumbrotorkid @ Jan 6 2003, 04:58 AM)

heres why i ask. whenever i drag race i shift into 4th almost at the end of the track and just wanted to know if that was right.i believe in 3rd i top out around 80...does this sound weird?



If you're doing any drag racing, it will probably be worth your time to do this: Get the diameter of your rear tires with a tape measure, then multiply by Pi and divide by 12 to get the circumference in feet. Your speed in any gear at any given RPM can be calculated by the following formula:



MPH = RPM * gear ratio / rear axle ratio * tire circumference in feet * 60 / 5280



My T2 is about redlined at 90 mph in 3rd with 24.5" diameter tires.

-=RX-7 KID=-

Thanks for all the info





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