Thanks for the feedback guys. Sorry, but I also forgot to mention that the car only engages forward like full throttle only when it is on the ground (i.e, wheels under load). When the wheels are off the ground (i.e, off load), the speed of the motor seems to repond smoothly through out the whole throttle range.

Does this eliminate the radio gear and leave the only option of tweeking the gearing? Also does the timing/punch values need to be adjusted if this solves my problem. I don't understand what timing is recommended or just left stock.