I just wrote up a spreadsheet to do this. If you want it I can email it to you. It's pretty simple, but it gives you max speed in each gear and revs at speed. You put in the variables like max revs, tire width, profile, wheel radius, diff and gear ratios etc. It's pretty simple to do yourself. Otherwise
it goes like this:
Tyre circumference = pi x total diameter
Total diameter = sidewall x 2 + wheel diameter
Sidewall = tyre width x aspect/100
eg. for 195/50 R15, sidewall = 195(mm) x 50/100 = 97.5(mm)
Make sure units are the same! IE convert wheel diameter (usually in inches) to mm. IE x 25.4
Once you have the circumference you can then convert this to metres. Then you know distance/revolution (wheel) then you just multiply in the diff and gear ratio you want and then you should get a relationship between engine revs and distance travelled. Then you can work out what you want.
Sun, 14 March 2004 01:05
