That exhaust gave me the biggest gain over all and is the only thing you can see not stock cept for my manual choke since I haven't permanently installed it yet. I still need carb tuned perfectly and get weights springs set perfect but I really like it I get close to 50 sometimes but cruise around 45 most of the time. That exhaust with stock everything else gave me better overall acceleration, higher top speed, and a huge rocket from 25 or 27mph even with two people on it. Now once I put BBK on I will tune it all over again lol. It's sitting in garage a probably won't start install till I have a beater to ride around.