Calculators
Straight From The Team Healey Texas Garages
An Awsum
Austin-Healey Speed Calculator
A real nifty way to figure out how fast you're really going!
The gauges in a Healey are notoriously unreliable - especially the speedo! Most drivers have learned to average out the wildly swinging needle oscillations. Even more likely, since the bloody gauge is probably broken, most folks just keep a sharp lookout for the cops. Since the tachometer generally works pretty good on Healeys, the following is in interactive calculator specifically set-up to allow you to calculate speeds at different RPMs, taking into account tire sizes, and any gear ratios that you may be running.
Try it out!
- Enter:
- the outside tire (tire) diameter in inches
- the rear axle (differential) gear ratio
- the gear ratio of a selected gear in your gearbox
- the overdrive ratio (in Healeys this is either 22% or 28% - or 0 if you don't have one)
- the RPM that you want to determine the speed for
Select the "Compute" button and the speed will automatically be calculated. You can enter additional values in the other rows to get additional speeds. Hitting the "Reset" button in that row, clears the row.
Tire Diameter (in inches) |
Rear Axle Ratio |
Gear Ratio of gear selected in gearbox |
Overdrive Ratio (typically 0, 22, or 28) |
RPM |
Speed in MPH |
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