dEcon you get more top end power. It doesnt really make it a better pipe. You sacrifice low end power for top end power. Heres a real simple and basic explanation. A two stroke pipe has different sections to it. The header, divergent cone, belly, convergent cone and stinger. The purpose of it is to harness sound waves, and to get rid of the burnt gasses. The divergent cone pulls the burnt gasses out of the cylinder and it pulls out a little of the unburnt charge (gasses) And the convergent cone pushes the unburnt charge back into the cylinder before the exhaust port closes. The belly is the section between the 2 cones, depending on how long the belly is, is how long it takes for the waves to travel back. so if you were to have a short belly the waves made from the convergent cone would travel back to the exhaust port fast, while that is good if youre at a high RPM it wont work too well if your at a lower RPM.