I have an RC 10 B4 RTR. It comes with a 17 turn motor, but I added a modified 17 turn motor. I cant go to a lower turn motor unless I change the electronic speed control, which I dont want to do. I am looking to increase speed through gearing. What is the lowest gear ratio that I can achieve that will fit on my car without changing the transmission? Please tell me the number of teeth on the pinion and spur gears. I am looking to get the gear ratio as close to 6 as possible.