I built a minibike type thing using a 101cc 3hp 2cycle snow blower engine, and I want to put a tuned pipe on it. The current muffler sucks.

I understand how the pipe works and everything. I just need advice on how to build one. Building it, physically, won't be a problem. I have plenty of different tools to cut and shape the metal, and access to a good mig welder that I have experience welding exhaust tubing with. All I need is help with figuring out what dimensions the thing should be.

Before anyone says to move this to gearheads, I already tried there. Nobody had any useful advice, and someone said to try posting it here.

The math to actually calculate the dimensions is too complicated to really be practical.

Normally you make the expansion chamber adjustable and tweak it until you get the power where you want it.

http://en.wikipedia.org/wiki/Helmholtz_resonance

Any gains are going to be minimal. I really want to get a drill press, slide vise, and rotary table and so I can grind cams. You could do something like that if you were so inclined.

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Except, I'm not making music and shit. And tuned pipes are one of the biggest upgrades you can do to a 2 cycle engine.
A 2 cycle doesn't have a cam. The piston acts as the valves.

Ahh, didnt notice the 2-stroke part. You mustnt have read and understood the link I posted. Everything you need to know is in there.

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455FE10422CA29C4933F95052B792AB2

Actually two stroke exhaust are more complicated than that.

The expansion chamber also cools the gas, causing it to contract, which pulls the exhaust from the next cycle out.

The cooling/contraction process is also tuned. The chamber is only resonant at peak power.

This might get you going:

http://www.mh-aerotools.de/airfoils/javapipe_en.htm

Well, it has stuff about intakes. And thats kinda interesting. I'll try to find a way to make a new intake then, instead of the one I have now. But, it doesn't have anything about tuned pipes that I can understand. All the delta t's and such. This is a guy who barely passed his last couple math classes. I need something easier.

Designing airflow parts probably wont be your bag then.

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All I need is something that is in plain English. Then it won't be a problem. Like if it has step by step instructions.

What's wrong with the link I posted?