Facts of shorty cans on exhausts; POST PICS!

[atvhonda-rider]

Hey guys, as you all kno you have or see the people trimming their exhaust muffler making it a shorty system, i'd assume it makes it louder and more torque? is that right or wrong? and FEEL FREE TO POST PICS of your shorty exhaust! :cool:

[400exrider707]

More noise is about the only thing you'll get out of it.

[XXXRACER165]

Little less weight, and more noise.

[Flynbryan19]

Not worth it.

[YFZ450Ridr]

i know you have to have a certain amount of back pressure to recieve good low end grunt. i would assume that with less back pressure you would get less torque but dont hold me to that.

[MAD450r]

The smaler can creates more backpressure causing the pipe to be better for low-end, but also makes it louder when you do this.

Thats why many racers run them.

[firefighterjosh]

Originally posted by MAD450r
The smaler can creates more backpressure causing the pipe to be better for low-end, but also makes it louder when you do this.

Thats why many racers run them.

I belive 90% of the back pressure is with the header pipe.

Shortened Pipe is not worth it

[400exrider707]

Originally posted by REDRIDDER
you are absoulty right.Just think of a pipe like the whitebrothers e -seriers less discs more back pressure= more torque less top end,more discs less back pressure = faster top end get what im saying?


You're saying the exact opposite of him, he's saying smaller exhaust is more backpressure. The can really doesn't offer a lot of backpressure its more the header, but the two combined are what creates the overall backpressure.

[atvhonda-rider]

Originally posted by 400exrider707
You're saying the exact opposite of him, he's saying smaller exhaust is more backpressure. The can really doesn't offer a lot of backpressure its more the header, but the two combined are what creates the overall backpressure.


no hes not saying the opposite... think about it, more discs equal a longer can, and more space so the exhaust isnt as crammed to escape, causing less back pressure, less discs equals its more crammed to get out, equalling more back pressure which equals more low end... and yes the header pipe makes the majority but as you said the combination makes it all. the less discs and shorter can are the same philosophy, just ones not reversable lol

[deathman53]

I have a tc shorty and it is really loud, I don't understand why people do this to pipes. People don't realize cutting out the baffles and packing from stock pipes doesn't make more power, just more noise. Cutting the pipe shorter, yes, it will make more low end, but alot more noise. As with my tc shorty on my hybrid, it will only be a matter of time before I can't ride it at tracks because its very loud. Notice most of your newer pipes are ~96 dbs, just at the sound limit and some have turn down tips too. A longer can generally makes for mid-top end and is quieter, shorter can generally makes more low-mid and it louder. Yes, the more backpressure= more low end and in some cases less noise(supertrapp pipes are the prime example, read there instructions, it will tell you so, more discs make more noise and more top end, less discs are for more low end and less noise).
Also, part of the reason why racers used the really short pipes is because of alot less chance of dnf'ing due to silencer damge from being rear ended or landed on).

[firefighterjosh]

Originally posted by atvhonda-rider
no hes not saying the opposite... think about it, more discs equal a longer can, and more space so the exhaust isnt as crammed to escape, causing less back pressure, less discs equals its more crammed to get out, equalling more back pressure which equals more low end... and yes the header pipe makes the majority but as you said the combination makes it all. the less discs and shorter can are the same philosophy, just ones not reversable lol

There is a big diffrence between disks and a open exhaulst.

Disks have more pressuer then open ended exhaulst.



Anyways I think HMF would have shortened the pipe if it gives more power. IMO there smarter then everday ppl wanting to make there pipe loud cuz it gives power :rolleyes:

[atvhonda-rider]

true that, yeah that makes since because i had a CT racing slip-on once, and they worked just the same as supertrapp, more discs more louder more power, less discs opposite effects, i think both theories kinda make since to me but now that i think about it i guess it would make since to have more discs= more pressure! it didnt make since before cuz i figured more discs more space to get it out at, but since those discs are so tightly spaced it would allow it to be more crammed if you had more

[400exrider707]

Originally posted by REDRIDDER
right on,atleast one person got what i was saying thanks for the back up.


:rolleyes: I was agreeing with YOU!

[atvhonda-rider]

i vote we're all retards for even debating the issue we only kinda kno what we're talkin about haha! :p

[400exrider707]

Originally posted by REDRIDDER
oh ,well he was saying shorter pipe so i meant that with less discs it also made the pipe shorter witch both = more back pressure.


This is what is confusing here, you guys are talking about apples and oranges.

A shorter pipe itself is not going to have more backpressure, it will lose backpressure.

Now where you guys are getting confused is with disk style systems. The last disk is usally a cap a solid piece. By adding disks in between the pipe and the cap, you are effectively making it more free flowing so in turn yes by having a "longer" pipe you will have less back pressure. Does this clear it up for anyone?

I've about had it with the confusion in this thread!:confused: :o :p :( :chinese:

[atvhonda-rider]

I've about had it with the confusion in this thread!:confused: :o :p :( :chinese: [/B][/QUOTE]

ditto!

[450rJam]

short can equals less back pressure (ever see a long can on a drag pipe ?)

if what you guys where saying about cut can = more pressure then by taking the can off it would completely plug it ???

[GPracer2500]

Backpressure does not help produce torque. Backpressure always hurts power; it can not help make power!

Exhaust gas velocity is what helps make power. Gas velocity and backpressure are too often confused with one another--but they are not the same thing. They may be linked to the same physical properties of an exhuast system but are nonetheless distinct.

The most effecient (i.e. powerful) exhaust system is the one with the highest exhaust gas velocity and the lowest backpressure.

[bwamos]

I shortened my old style Sparks X-4 exhaust can by 2 inches.

I did it for 1 reason and 1 reason only. I was tired of worrying about accidentally standing it up on the grab bar and dragging the exhaust (ripping it off).

Shortening it by 2 inches made it so the grab bar would clear past the exhaust making it so it could be stood up on end.

It made NO noticable difference in power one way or the other. To counter the dB increase I put in a better sound absorbing exhaust packing.

Here's a pic of the pipe after it was shortened. The orginal exhaust can extended almost to the edge of the picture.