Imagine a circuit that is a perfect circle, such that you are at a constant speed throughout the lap. This circuit would be gearing insensitive. You could run basically any gear that allowed the engine to keep the kart at that speed.
Now imagine a drag strip. The length of the strip is going to determine the rpm/speed range over which you will need to operate. The longer the straight, the bigger the range. This will dictate an optimum sprocket.
Kart circuits are somewhere between the two. Some will have a small speed range where min speed and max speed are pretty close. Others will have a larger speed range, where min speed and max speed are far apart.
How does this help with gearing? If you race at a circuit with very tight corners and very long straights, you're going to have to rev your engine. The time made up getting off the corners quickly might be more than the time lost at the ends of the straight. If you race at a circuit with fast corners and long straights, you might find that faster laptimes are achieved by operating around peak power for longer.
As an example, in Comer's:
Rye House: Min Revs: 6000, Max Revs: 12500 Wigan: Min Revs 8000, Max Revs: 12100
Rotax is a little more complicated because it has a small surge of power above 12,500rpm which at some circuits is worth using, and at others not so much. If you're not sure if dropping teeth will reduce laptimes, try it. This will give you a much better answer than any you will recieve on here.
|
|