Originally Posted by fox947
Hi have a T4 xray with a 17.5 brushless motor,rear diff and solid spool in front. Rubber tires 2.5 inch Dia(64mm Dia). I did the gear wizard to find the roll out for a(64 Pitch) 100 spur and a 43 Pinion giving a 1.777 roll out. How do you know the most efficient gearing to produce the best value at the proper temp, other than trial and error or are their sheets giving best roll outs for that particular gearing. any suggestions, Thanks pete
It's all trial and error. It's going to be based on the track layout and driving style. There is a base that you can start with which would be about a 4.0 FDR and adjust from there. You want to check your temps to make sure your not overhearing. Different motors/rotors like different timing and gearing so you will just want to try and see what works best for you. I usually gear mine at a 3.72-3.9 and usually try to gear to about 140* on the motor.
Most people gear to FDR not rollout so to compare your setup to what I show you are at a 4.41 FDR with the 100/43 combo.