My target RPM is 6200 on a green plate big pipe, biggest driver I can get away with, Usually 1 tooth above what the adult classes are running. SO if their on a 13 were probably on a 14, Carries more speed into the corner and with a 100lb weight advantage over say the 350# class we scrub off less speed, Thats how we can normally get away with going 1 bigger. Now if it seems like it is going to be a wreck fest with multiple cautions ill drop a tooth just to assist on the restarts...... Very few times has it worked in my advantage though lol