Build or buy expansion chamber?

[Street Ryderz]

The power band is determined by the pipe and porting not the shift kit!And a pipe that works at the top rpm isnt really the best for many reasons!If your pipe comes on in the midrange then its helping the engine to reach its topend by making the power to overcome the gearing!

 

[Jonj57]

You're right about the powerband, but the shift kit keeps you in your prefered RPM range so if you set it medium to high range you can keep on the band thru the gear range with the exception of low speed cruising/take offs, but even then I have more than enough power to start from a dead stop. Reed valve and boost port let you use the low end like it's a tractor.

 

[Deleted member 12676]

I'm not a fan of loud motocross pipes on these engines.
consider that they only have a 2000 RPM powerband and they lessen power before it comes "on the pipe".

 

[Jonj57]

While not absurdly stealthy I use a pipe adapter and some hose clamps to attach the standard muffler to the pipe and it brings down the sound a lot! Not sure if it takes a significant performance hit but it's worth bringing the sound down to almost moped levels

 

[BikeBuilder43]

I have the thrust racing muffler. I've been noticing a loss of power and realized I had some exhaust leaks. I used a 2 part putty that hardens. It has the consistency of play dough at first then hardens enough to grind on. I filled in the leaks and partially closed off the stinger. It is now a little smaller then the header pipe and I saw a noticeable difference in mid range torque. I also picked up about 2mph on my top end. Has anyone else tried this?

 

[Jonj57]

Means you had too little back pressure and you brought it closer to in-spec by making the hole narrow.