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Author Topic:   Tire rpm help
Whitelightning
Dirt Freak

Total posts: 429
posted June 22, 2005 07:14 PM  
What will be the rpm diffence be if we switch to a 275/60/15 from a 245/60/15 I know the 245 role out between 82 and 83 most of the time. We were turning 6500 and Idont wanna tyurn new motor that hard. I want to be between 5500 and 6000.

te33
Dirt Freak

Total posts: 237
posted June 22, 2005 07:26 PM  
my tiger paw 275's are 87.5t-88.625,that will take your rpms down some,not sure exactly how much.coopers tend to run bigger on roll-out than uniroyals.

fastrack1
Dirt Maniac

Total posts: 145
posted June 22, 2005 07:31 PM  
1 INCH OF TIRE IS WORTH ABOUT A 100 RPMS USE THE TOOL BOX ON HERE IT WILL GET YOU REAL CLOSE .

Whitelightning
Dirt Freak

Total posts: 429
posted June 22, 2005 07:38 PM  
hey te33, we turned that thing 5900 in screven That Is why I am worried now about swainsboro, but he was slinging that thing in there all sideways and spinnning like crazy. So it worrys me now lol

[This message has been edited by Whitelightning (edited June 22, 2005).]

racer038
Dirt Maniac

Total posts: 111
posted June 22, 2005 07:50 PM  
I looked up various tire diameters on tirerack.com. The percentage difference in size between the 245 and 275 tires you mentioned is around 5.7%. All other things equal, this will reduce your RPM 5.7% to around 6130. If you need to stay below 6000, try 255 70 15 tires. They are HUGE and will reduce your rpm by 8.7% (in theory). If you have slow starts now, you'll get slower. If you have trouble with tire spin off the corner, it may help. Good luck.

    

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