Please explain exhaust theory to me

[portokiwi]

Thanks for that

[stormy1]

What can i say. As long as they dont rob power i'm all for an exhaust syetm that makes a bike sound like a bike! Just love the sound of the two brothers cans on my VTR! Sound good, look good = makes me feel good, no more needs to be said!

[FROSTY:Me]

Short version.
Factory pipes have to do their bit to help the bike perform as well as keep its noise town to a level accepted by whatever countrys gubiment the bike is sposed to be sold at. AND has to pass the emmission laws of said gubiment.
Aftermarket pipes in NZ dont have those worries.

What it means to you is that within reason you can buy a louder pipe cos it sounds good.
You can buy a pipe which has tuned size/width to suit better bottom end,midrange or top end.

Thats the simple version.

[wharfy]

have a read here, you are pretty brainy so it should answer some of your questions.

http://www.burnsstainless.com/TechAr...ry/theory.html

Pretty good read...

All that good stuff is directly related to the intake side as well - You have to consider the entire FUEL system from airbox,intake,carb/injector,inlet-tract,inlet-port(s),combustion chamber,exhaust port(s) and everything after that.

Modern bikes have to consider emissions, noise, economy, as well as performance in the market the bike is intended for.
Change any of the components of the entire fuel system and you will compromise some of the others.

BUT knowing ALL that I still removed my bikes vacuum operated intake flap (noise control for the rev range measured for compliance) fitted a K&N filter and removed a bit of the exhaust baffle with NO evidence that it has altered the performance/economy/emissions (for better or worse) but it does SOUND much cooler now (and still gets a warrant)