Originally Posted by
English365
Anyone running the reedy Mach 3 17.5 1s with the 12.5 rotor in stock? Gearing and timing?
Gearing is going to be more about the surface and layout than anything else. I can tell you now, you're going to need to figure a fan out, as the short stack motor is pretty sensitive to heat fade.
I would start at 43 degrees of timing, 32x72, and work from there. When you run a fan, you worry less about temps, and more about feel. I would tell you, run 4 laps with this setup, then try a 31. run 4 laps, then try a 33. Once you find the right feel and speed, and lap time, run for 8 minutes and see how it feels around the 5 minute mark, if it's not fading, bump timing up a little.