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Author Topic:   rpm's/tire change
turnleft43
Member
posted February 18, 2004 05:41 PM
Ive been using tires that roll out at about 83 inches and I get about 6200 rpms at the end of the straight's on a 3/8's mile track. im thinking of changing to tires that roll out too 91 inches for a 1/2 mile track to get the rpm's in the ball park for that length of track. Will this work ?


BK19
Member
posted February 18, 2004 05:43 PM
it might but what rearend gear do you have and what trans and gear do you run in


joetaylor
Member
posted February 18, 2004 05:58 PM
543 FOR A FINAL RATIO ON A HALF MILETRACK

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U LIFT U LOOSE


racer038
Member
posted February 18, 2004 07:39 PM
I'm not sure my experience is sound for dirt, but when I went from 3/8 to 1/2 mile on asphalt, I went from a 6.07 to 4.68 final, using similar size tires. That's like a 23% change in gear for a 25% change in distance. You look like your changing distance by 25% but only changing gear by 10% (with the gear change only in tire size). I would be worried about winding it out too high by only changing tire size. Lots of other variables will affect reality, but I think it's a little risky.


racer17j
Member
posted February 18, 2004 07:49 PM
that seams a little drastic to me i would go with say a 86-88 first i run a 4/10 and small 1/2 and run the same tires only about a 300 rpm difference if i would run the same tires on a 3/8 would only exspect another 200 drop


hsracer58
Member
posted February 19, 2004 01:16 AM
We run a 6.00 gear and the two speed power glide in high. Both of these tracks are true ovals and not a circle like eldora. I know there u need a 4.86. The 5.43 range is right but i was hoping to make up for it with tires and not having to change gears every week. Im going to experement with this and hope the tach tells me something good. Thanks for all the replys and any more is appreciated.


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