yea i know i'm doing it backwards but when i bought it i didn't know it was an 18 mph, less than a horsepower, model...so it was slow as crap and wouldn't do anything around here, i looked for a 30mph topend but couldn't find one so i just kitted it. but i really was just woundering what pipe i should go with to increase topend. and which gearing would be better. i've already done a search and looked at the different pipes but i'm stuck between the three (bullet/boss/bi-turbo) or is there another one. i can do metal work so i can use any pipe.