Posted by Roy Sanders on Sunday, November 19, 2000 at 16:34:19:
In Reply to: Max Speed of a C-3-PW posted by David Pratt on Friday, November 17, 2000 at 21:13:50:
For manual transmissions without overdrive:
RPM = Gear Ratio x MPH x 336 / Tire Diameter
Example: A Powerwagon with 5.83 gears and 36 inch tires, traveling 45 MPH will run at approximately 2450 RPM.
Keep in mind this formula is approximate and will depend on other factors inherent in your particular vehicle.
Here's some other formulas:
Gear Ratio = RPM x Tire Diameter / MPH x 336
For vehicles with overdrive:
RPM = Gear Ratio x OD x MPH x 336 / Tire Dia.
For manual transmissions, OD = .8
For Automatic transmissions, OD = .7
For automatic transmissions without overdrive:
RPM = Gear Ratio x MPH x 335 / Tire Diameter