Hey Drew this is CREWS from Wolf Pack i run a Ninja at Wolf Pack and have been running a 086 pipe but the motor did not have anuff bottom end so i am trying a 063 and i all so have a 053 so far i like the 063 lots of bottom end and lots of top end i will be running at the track this weekend if you wont to try some of the pipes i have.
I have all so been running a 8 restrict helps in flue but don't hurt the motor on power the best i can tell.