tire swap what rpm
08-25-2008, 09:41 AM
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CRAFTSMAN
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Join Date: Mar 2005
Posts: 59
tire swap what rpm
we are running a s-10 350 sbc , turbo 350, with ford 9 inch with 4.86 gear.and hoosier 32.0 x14.5 x15. want to go to smaller and shorter hoosier 29.5 x 11.5 x15 right now at finish line we are at 6000 rpm's .any ball park idea what rmp might be now. thanks.
08-25-2008, 11:11 AM
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Location: Rifle Colorado
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I'd say around 6400-6500rpm.....
08-29-2008, 11:44 AM
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Join Date: Mar 2003
Posts: 127
4.86 32"tall tire @6000 RPM
should be @ 118 mph
if the only thing that chages is RPM then these would be your #'s
4.86 29.5" tall tire at 118 mph
should be just over 6550 RPM
11-05-2008, 03:59 PM
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my math @ 118 mph would be a tick below 6500.so id split diffrence and say right on at 6500,good luck
11-05-2008, 04:49 PM
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RACING JUNKIE
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speed
According to my spreadsheet, the RPM will be 6505 @ 117.83 mph.
But, the only sure way to know is ,DO IT.
11-05-2008, 06:21 PM
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MPH X 336(WHICH IS THE CONSTANT) X REAR GEAR RATIO / TIRE DIA.
THIS FORMULA WILL WORK NO MATTER WHAT MPH YOU PUT IN.BUT THIS FORMULA IS WITH A TIGHT CONVERTER.A REAL LOOSE CONVERTER WILL OBVIOUSLY BE MORE RPM.
11-05-2008, 06:25 PM
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Everytime I change tire size every inch is about 2-300rpm in the 1/8th.
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