homemade headers/exhaust

So has anyone here fabricated their own exhaust system?

I'm looking for some stories so I can get a sense of how difficult it will be and what kind of performance I can expect. It seems to me it can't be that expensive to build a set of pipes yourself and if those idiots(not to say i don't like them) on OCC can do it I figure i can to.

I'm also looking for more theory behind the whole design of headers and exhaust systems, so if anyone as any knowledge they wish imparting or recommended reads I'm all ears. I'm currently reading 'Four-Stroke Performance Tuning' and I love it, I definitely recommend it to anyone who wants to know more about the theory of how an engine works and how all the parts and pieces fit in the big picture.

happy tuning and riding

I know a couple things. For the best performance you want the head pipes as close to the same lengths as you can and the shorter the head pipes are the better for high RPM HP and the longer they are the more low end power you'll get.
Mark

what are you wanting to build, 4 into 1, ?

tube size is also a issue, along with heat transfer, and you do need to keep the tubes the same length.

one good way to think about air flow , is to picture water in your mind, air and water flow the same way they dont like to bend, so you want to keep the bends equal and smooth

From what I can remember, by using graduated pipe diameters (smaller to larger?) you can create more of a vacuum that pulls the exhaust out of the cylinder to get a much cleaner burn.. does that make sense? As the gasses expand going into the end of the pipe, it sucks the rest of the stuff with it..I think I read something about that - somewhere!

So BSK, I want to make some exhaust on my 1000 like my SR. Would that be a good idea? And what materials am I allowed to use and how do I make it without welding? Pipe benders? This may sound stupid but how would aluminum stand up against the heat? I have a ton of questions that can lead to just one guick and easy question, but hard to ask.

depending on how many bends you need, and how tight you need to make them, I think welding will need to be a part of the process.. Though I am basing this on what I've seen on OCC, so it could be a load of crap! heheh.. ah I4s..out, down, and back.. so much easier!

Holy Cow! Hey, just my two cents worth, but home-made headers are the best way to screw up a bike's performance. There is a whole lot of science that's taken for granted in this topic. so,
#1. The material you use is very important. No, aluminum won't work. Cast aluminum might, but that's only because there would be enough mass to act as a heatsink and dissipate enough heat so that you don't burn a hole in it. But even the steel tubing you use matters. Header manufacturers have a lot of experience in choosing the material, and every so often THEY get it wrong.
#2. Tube bending for exhaust headers either takes a very expensive machine, or true artistry. bending it badly is very easy, and will be so detrimental as to waste everything else you can do.
#3. welding is not just required, you really need to be a GOOD welder to not muck it up. Sorry.

All in all, I don't recommend trying this. Spend your energy on something you can do. Like building your own fuel injection system. Really.

Thanks for that useful piece of info pstrbrc, that was more than 2 cents worth. I think I will try your electrolysis thingamajig

kzwolfsr wrote:

Thanks for that useful piece of info pstrbrc, that was more than 2 cents worth. I think I will try your electrolysis thingamajig

:blink: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo: :woohoo:
OOOOOH!!!! Dang! That one ZZZZZZinged!!!!!

I don't think you can make something high performance without welding.. Aluminum is not really an option I don't think. Try throwing some aluminum in a fire The muffler might be cold enough to use aluminum though.
I imagine you could make the header without welding, it's where the 4 tubes come together that I can't see any way around welding. If you could actually find all the materials, bend all the tubes yourself it probably wouldnt cost much to have someone weld it all together for you. Sounds like a lot of work to me .

Ron

It's ALOT of work, all right......and all I had to do was re-make a collector! (Bike vs. mailbox post) Cutting the tubing....fitting it up.....cussing and throwing.....welding......grinding and recutting.....cussing and throwing.......etc etc etc.
On the up side....I DID save myself 300+ dollars for replacing.
If you were to do one up from scratch.......well, all I can do is wish you luck.

you could always buy prebent pipe and weld it up the way you want it;)

Post edited by: wireman, at: 2007/04/12 14:42