so today i was in policecustody for riding a 47cc mini bike on the streets at the age of 15 aparently im fooked due to no licence registration speeding blowing off a stop sign and riding "wrecklessly" well now that thats over with i plan on making the wee littl bike faster. im goin to build a new frame with non crap welds and over all larger so i can actual put my feet on the pegs, i want to know if building an octoganal or similar shaped expansion chamber is sensible. i have all the tools except a pipe desinger to get dementions. is cone shaping the only way to get efficent flow and preasure waves? let me know thanks