What is the formula for finding out speed from rpm, trans gear, rear gear and circumfrence? I need to know soon. My VSS isnt hooked up right now. And dont tell me to go to the calculators, I want to know the formula.

James

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If the women don't find you handsome they should at least find you handy

[This message has been edited by scooter (edited November 03, 2000).]

 

The formula is there.

[This message has been edited by MRZ28HO (edited November 03, 2000).]

 

MPH = tire radius ~ 168 X engine rpm ~ gear ratio

28" tire = 14" radius

Gear ratio = 4.10

RPM = 6000

Example #1
Transmition ratio in 3rd/drive = 1

14 ~ 168 X 6000 ~ 4.1 ~ 1 = 121.95 mph

Example #2
Transmition ratio in second = 1.34

14 ~ 168 X 6000 ~ 4.1 ~ 1.34 = 91 mph

Mike

 

Are you using the ~ as a divide?

James

 

Nevermind about the second post. How do I make the formula have the rpm as the variable but the MPH is known?

James

 

Ya, the ~ is divide. Spose I should have used \ for the symbol.

RPM = 168 X gear ratio X MPH ~ tire radius

Same parameters as above:

RPM = 168 x 4.1 X 1 X 121.95 ~ 14
RPM = 5999.94 (not exact but close eh?)

RPM = 168 X 4.1 X 1.34 X 91 ~ 14
RPM = 5999.448

I got these formulas from the Edelbrock sight a couple years ago. They had all kinds of formulas, you might want to hop over there and check them out if they're still there.

Mike

[This message has been edited by md (edited November 03, 2000).]