Exaust system

[Anonymous]

Hi i was recently looking at my exaust and noticed that the exaust pipes are double layered one smaller one in the inside that flows the gasses and probly keeps it quiet and the other a bigger chrome pipe over it.....i was wondering if i made just custom exaust like they do with the choppers...just big pipes coming out of the head with no muffler, like just 2 inch pipe......this would be more flowing and also sound much better would this effect engine performance or lifetime is there anything i could do..............................................ri ght now i actually have the pipes cut off right before the mufflers in the back those were garbage its jus the pipes now its sounds awsome with a deep rumble.........id probably jus end up using those because they are so nice and fit the head so well, but if i ever wanted to really customize the exaust id just use 2 inch exaust pipe and make bends

[lhanscom]

Yes you can do a custom exhaust, but if you're looking for power, not just sound it takes some work, and trial and error. If you're looking for more flow it's best to join the pipes together, at least a 4 into 2 design, or you can go 4 into 1, or better, 4 - 2 - 1. Where the connections happen makes a difference. The idea with joining the pipes is that the flow from one cylenders exhaust pulse will create a vaccum for when the next cylender breaths out it's exhaust, making the exhaust flow better. BTW, if doing a 4-2 or 4-2-1 you'll want to join 1 and 3, then 2 and 4, to get the best results. As a rule of thumb, short fat pipes make a narrow, but high HP, like a dragster needs, but bad on the street. Long skinny pipes make good low rpm hp, but don't work well in the higher rpms, so don't do well for peak power. The best combo of the two relies on what you want. It's also possible that you will need to rejet your carbs after messing with the pipes.

If you're just going for sound, and not power, do what ever you think sounds best. IMHO if you're gonna shout, you better have something to shout about. The harley guys are notorious for loud pipes, but they have nothing to backup what they're advertising, I do find it humorous though.

[crayonjota]

You have been given some sound advice, and I would like to add that I have a supertrapp system on my bike, that allows for me to "adjust" the sound by adding and removing baffle rings, or going completely uncorked.

Uncorked I get a very deep rumble and the bike works well up to about 7000rpm, where the power trails off.. With all the baffles in place and everything tightened down (causing most back pressure) I have a typical jap bike wail and I make power from 7000 through 10,000 rpm. Much more power... Maybe this is the solution you require. Loud and rich for cruizing and screaming for Sunday morning scratching.. I use an air ratchet to do the necessary spanner twirling, and it is a 5 minute job... CJ