Still doesn't make sense.

[QuadParkour23]

I have always thought expansion chambers only worked on two-strokes & there exhaust systems. I have the Dasa Joe Byrd Limited Edition exhaust for my 450R, and it has a small tube like thing on the header pipe. I have no clue to what the tube does, can someone help me out?

[kaw45026]

lowers sound output.

[veenser2000]

Both previous statements may be true... here it is straight from dasa

This TRX450 Dasa pipe is handmade here in the USA and the quality really shows with perfect tig welds, trick billet end caps, a billet canister mount, thick head pipe flange andthe end caps do unbolt for easy canister repacking.

This pipe will meet 98 db restrictions without any HP loss... NO QUIET CORE AVAILABLE FOR THIS VERSION.

I think your right smoker the actual exhaust portion is more restrictive while the header is used to generate more power vs. a conventional header therefore keeping the overall power output the same!

[Sjorge450R]

its for sound. I beleive the pipe still has the same HP #'s as before, but now with all the series gettign serious about sound, they compromised and made a header that looks rediculous so that they could lower sound levels and keep the power the same.

[pro-rider46]

i would think that the actual tube itself would quiet it down because the sound bounces around and is like a resonator. but idk.

[motomxman450]

someone hit up roostar or somthin idk his user name but he had a topic with his race bikes and explained it there..... long story short its for both, power and sound. i alows you to run no core but still be quiet, so therfore you make more power cuz no core but sound as if you have one in. and yes it was developed to meet noise restrictions without loosing power