its easier to find a motor and adjust the gearing to keep the motor in the sweet spot for each track.

a motor with lots of low end torque and efficiency could perform well on a short track or a motor with lots of mid or high rpm torque for a long track but you would need 3 motors or something that is a compromise. to pick a motor per track you would need dyno curves and the ability to calculate average speeds of each track. its not for the the faint hearted.

have fun and get a good motor you can afford. if you want the right motor and gearing for a specific track ask about a specific track probabably at the track.

or calculate the average speed per lap of the track and pick a motor that emphasizes torque in the area you want. Then calculate the FDR and roll out.