All engine manufacturers have their pipe selection for their engine models, and also a selection oh headers in different sizes. Basically they have pipes which enhance low end power (torque) and others which enhance high end power (high RPM), and different lenght headers (shorter= more RPM, Longer = more Torque). So if your track is tight and twisty you´ll probably best suited with a torquier pipe, and if it is a fast flowing track where you are at the gas most of the time, you are better with an RPM pipe...if it is a mixture between fast and tight and you´ll probably need the rpm pipe with a médium or long header.

By the way waht engine do you have? is it 1/10 or 1/8th On Road??

AFM