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Author Topic:   tire size
Dirt Full Roller

Total posts: 38
posted May 05, 2002 06:03 PM  
Changing rear tire size, from smaller to bigger or vise versa, what does that do to speed and rpm. I run on 3/8mi semi oval clay track, running 2.5 tranny and 3.08 gears, current rpm around 6900. Can i gain more by changing tires, I finish ok most times but like to do better

Dirt Full Roller

Total posts: 68
posted May 05, 2002 09:55 PM  
1" of tire roll out = 100 rpm. hope this helps..

Dirt Full Roller

Total posts: 48
posted May 20, 2002 04:55 PM  
I'm still building my CRX. Here's my ?... Some models ofCRX came with 13" rims stock. Mine came w/ 14" stock. The track I will be running requires stock tires/rims for your car. It is a 1/4 mile partial clay surface carved out of some farmer's field. Do I go 13" for bottom end or 14"?
ANY help would be appreciated.

Dirt Freak

Total posts: 265
posted May 20, 2002 06:50 PM  
if you run taller tires you will go faster but loose acceleration. smaller tires will help acceleration but you will loose top end speed. if you want to find out your final drive ratios with the tires on. put a chalk mark on the top edge of the tire and put one on the axle and turn the tire one turn and count how many times the driveshaft turns and that will be your final drive ratio. if you rotate it once and the driveshaft turns 2.65 times that will be yur final drive ratio with the tires on.

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