Another exhaust question

[xraytoken]

I'm going to modify one of my Sportsters this winter and I have a coupla exhaust options. One of them is to take the samson pipes I have now and cut them short,kinda like a board racer type look and then wrap them. They'll pretty much dump the exhaust straight down. When i do this it will cut off all the existing support brackets except where they clamp to the head. My question is: Will I need additional support for the short pipes or will the clamp at the head hold them? I've looked at pics of other bikes with this look and can't see any extra support.

[alainmengoli]

You might get away with no supports. Be aware that cutting them so short will cause your engine to run really badly. You need back preasure or you'll loose a lot of power and driveability in the real world. Good for drag racing with full throttle 100% of the time bad for cruising. You might be able to compensate these with some insert but that will ad weight then you might need brackets.

[Flamin883]

why do people say you need backpressure for an exhaust. back pressure is BAD and should be avoided at ALL COST. I'm not saying they won't make it run bad because you cut them short, but it WILL NOT BE BECAUSE OF LACK OF BACKPRESSURE. the short pipes may cause reversion witch IS backpressure but as a general rule you DO NOT want backpressure from an exhaust that is totaly contrary to the idea of adding a freeflowing exhaust to increae preformance blah blah blah

[Weo]

Originally Posted by Flamin883

... the short pipes may cause reversion witch IS backpressure but as a general rule you DO NOT want backpressure from an exhaust that is totaly contrary to the idea of adding a freeflowing exhaust to increae preformance blah blah blah

+1 From my understanding, the shorter the pipes, the further up the RPM band the reversion effects (power robbing) happen. Baffles/lollipop will add resistance to the system and help reduce the harmonic effects for vaious reasons. This is good and bad in that it lessens the power robbing reversion at the lower RPM, but also reduces the power gaining scavenging effect at the upper range.

[DogBunny]

I've been singing the praises of the lollipop mod for a while, I thought it added back pressure, but I recently learned, as has just been stated, that the lollipop is for anti-reversion. In any case, it works. Here is the link:
http://xlforum.net/vbportal/forums/s...d.php?t=247790
You need to do this if you run open pipes.

BTW, I believe that in general, the shorter the pipes, the louder they will be. Yours will probably be extremely loud if you do this, unless you put a baffle in, or something.