For the pipe gurus...

[Scro]

What part of an exhaust system determines whether it is more of a mid-top exhaust or bottom-mid exhaust? I would think it would be more in the header, rather than the silencer.

[4TraxRider]

From what I've understood about pipe building it lies within the diameter and length of the header. But I just buy them and read about them.:cool:

[400exstud]

Every part affects this

Small diameter = more vacume = more low end
Large diameter = more flow = more top end
Long header = more low end
Short header = more top end

Generally:
Short canister = more low end
Long can = more top end

[2muchquad]

That is so true.If you notice the mx bikes during the supercross season,they run the "lowboy" pipes which means longer header for lowend style of delivery and for the outdoors the pipes go almost straight back for a shorter header and tiop end for the faster mx tracks.

[250exrider15]

400exstud, i have the 2003 style curtis sparks X-4 for my 250ex and my hearder pipe is big but its also really long and my canister is pretty long to so what power increase would i get with cause both are long????:confused:

[250exkid]

thats my friend that tryied to type my stuff ill explain my question better. well 400exstud said the powerbands and stuff well what would my power band be if it has all oppisits? my header pipe is big and really long..... and my canister is big to and long bigger then HMF, this is the 2003 style sparks X-4 for my 250ex so what gains and power ups should or am i getting???:confused:

[400exstud]

What I stated about the pipe characteristics is taking into account that that would be the one thing that would be changed and all other groups would be controls. As for what happens when you change more than one thing at a time............that's a question for the dyno.:p

[wilkin250r]

Give me reasons. Don't just tell me that a short canister makes more low end, tell me HOW and WHY it happens.

[Ron89]

Don't take my word for it but I think I read a short silencer gives almost no performance advantages other than it not getting mangled in a race from sticking out too far.

Originally posted by Ron89
Don't take my word for it but I think I read a short silencer gives almost no performance advantages other than it not getting mangled in a race from sticking out too far.

Yeah my pipe dont seem any better since i shortend it. All i got was more noise and better looks.