which pinion gear to use?

M3Jokster · 11-20-2002, 02:48 PM

i have a 70 Spur gear.....and an 11 turn motor.....
what pinion gear should i use......

i have a TC3..

which one gives me more torque (low end)? Speed (high end)? and both.

TIA..

M3Jokster · 11-20-2002, 02:49 PM

also....is there a formula out there so that i can calculate?

Speedo · 11-20-2002, 03:40 PM

The formula is spur/pinion * the internal drive ratio of your car.

EX: you have a 70 spur, 25 tooth pinion and your DR is 2.2 - 70/25*2.2 = FDR The lower the FDR (final drive ratio) the higher top end, the higher the FDR, the better the acceleration. Thus, a smaller pinion yields better acceleration, and a larger pinion yields more top end.

I can't tell you what pinion you should use, it really depends on your track.

Steevo · 11-20-2002, 05:51 PM

Speedo is 100% Right. It depends on a lot of factors that you have not mentioned like Internal drive ratio, Tyre diameter, Type of track etc.
If you search for the "Rollout figures" thread you will find a handy formula to give you an Idea of where to begin gearing your car. It provides a useful starting point from which to work from.

Steevo