Autopsy1

I run 19T, 27T motors indoor on carpet(19T) and on wood(27T) the track is about 1.5-1.8 wide and the straight is roughly 20 -25 metres long. My current gear ratio is the standard setup 6.5:1. I was wonderin wat is the highest gearing ratio and the lowest gearing ratio for each motor roughly that i should run so i dont damage the motor.

jgroenhof

iTrader: (3)

I don't really know much about your car there. You didn't say. Plus I drive offroad. But this should apply.

Don't worry too much about damaging your motor. The only real damage can happen from overheating. If you can't hold your thumb on the motor for 5 seconds it's too hot. (check it every couple of minutes at first, and don't burn yourself) If it's too hot gear down (use a smaller pinion gear). The motor will get warm, that's OK.

Other than that a car should ideally reach top speed at the end of the longest straight. That's a general racing rule, which applies to all racing vehicles.

Even years after you have the right gear selected you should check that motor temp after each run. It can warn you of other problems.

Autopsy1

cheers mate
by the way i run a yokomo MR-4TC

tc3team

Heres a little formula to help you with gear ratios.
the number of spur gear teeth (s) divided by the number of pinion teeth(p) times by internal gearbox ratio (igr) = final drive ratio (fdr)

simply put is s / p X igr = fdr

advanced drivers will use the fdr to describe their gearing, so even if no one else uses the same car as you, you will still be able to understand the final drive ratio of their motor. (hopefully its the same type/brand/model of motor as yours).

ask a friendly pro at your track what fdr they think is best for the track and gear your motor accordingly if you dont use the same motor as them ask them for some advice as you may need to be geared slightly different.

sinisterRC

iTrader: (9)

how do you figure out internal ratio??

jgroenhof

iTrader: (3)

Unless you've made any changes within your transmission.

Per the XRAY web site you have the "World's most efficient drivetrain with a 1.7 internal ratio"

sinisterRC

iTrader: (9)

thanks.

Marcos.J

iTrader: (239)

http://www.gearchart.com/index.cfm?f...n=chart.create