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               MPH and RPM Calculations


At some point you may be curious as to your top speed in a certain gear, or how changing your tire height will
effect your mph at the end of track.  There are endless variables with the different transmission gearing, ring and
pinion ratios, and assorted tires.  The following calculations will give you the information you need to make an
educated guess as to how your car may perform.


Engine RPM:
                 RPM = MPH x Transmission Ratio x Gear Ratio x 336
                                                     Tire Diameter


Miles Per Hour:
                                     MPH = RPM x Tire Diameter
                                                    Gear Ratio x 336


Gear Ratio:
                                   Gear Ratio = RPM x Tire Diameter
                                                              MPH x 336

Transmission Ratios:

        Stock T-5 World Class                                 G-Force Street T-5
        Tremec TR - 3550                                        Richmond Street T-5
                    TKO 500                                          Stock AOD
                    TKO 600                                          C4 / C5 Automatic
                    TKO 600 Road Race

Available Charts:


MPH by RPM and tire height


RPM by MPH and tire height

Ford Gear Ratios
8.8"
9"
2.73
3.00
3.08
3.25
3.27
3.50
3.55
3.70
3.73
3.89
4.10
4.11
4.33
4.30
4.56
4.56
4.88
4.71