Originally Posted by kn7671

I would think mostly as a fine tuning option. Most running mod used to have one option to increase runtime, reduce heat, or get more speed, and that was to swap to a different mod motor. Not uncommon to see guys switch between a 3.5 up through to a 7.5 to tune the car for the track, BUT NOW with the software punch and timing options in the speedo, you can get that extra speed down the straight w/o having to change the gearing or changing motors.