anyone make their own header?

[ITS_NOT_A_KNIFE]

wondering if anyone has ever made there own header? i have a full v&h ss2r exhaust but i like to make stuff. made my own foot pegs, bar ends, and working on a swing arm with a 4" stretch...(i work at a machine shop). anything to watch out for on the header, and how big should the primaries be

[87vert]

why?

I once modified a set shorty mustang headers by flipping them over so they face the front and welded turbo flanges to them for my twin turbo setup.

But thats because I was too cheap to buy turbo headers. if you already have a header why bother?

[The CyberPoet]

If you decide you want to fab up your own headers based on the design of the V&H, look to match the tube lengths exactly in terms of where the curvatures start/end and the degree of bend, as well as how the collector comes together. Then to improve the design, replace the down-tubes from where the first bend just a little bit past the exhaust port is, all the way down to just past the second bend (where the curve to head rear-ward towards the collector) with oval tubes (instead of round ones). The ovals should be wider (left-to-right) and narrower (front-to-back) than the existing round tubes.

Doing this should give you a performance benefit, because at low engine RPM's, the narrower tube will alter the tumbling effect (less expansion room and more surface area that it will smash into at that first corner) and increase the back-pressure at the exhaust valves, improving low-end torque a bit. At high engine speeds, the gas will tend to stream better through the oval tubes and tumble less because the tube-shape matches the flow-shape better. It's a trick many of the GP bikes use.

Aside from that, I can't see any other changes I would suggest making, unless you want to increase the size of the collector's exhaust section (rear of the collector), but you'd need a different midpipe to compensate.

No matter what you do, you'll find that you will need to get the bike with the revised headers on a dynometer with exhaust analyzer and tune the fueling to compensate.

Cheers,
=-= The CyberPoet