posted September 11, 2003 12:18 PM
Mathmatically this is really easy guys....Take the new ratio and divide by the old ratio to get the % change  then use your current RPM's and multiply by the result... So say you're running 6000 RPM right now with the 5.43, and you're going to switch to the 5.83 5.83/5.43 = 1.07366, (or about 7%)  multiply that by the 6000 RPM and you get 6441 RPM to turn the same "speed" Of course the reason you're doing this is to get the engine into a better area of the power band, so the net result may be more RPM's or less RPM's depending, but the calculation will get you a direct relation to MPH for the effect of the gearing change
