I have several questions concerning tune-pipe.
1) How does a tune-pipe improves the power of an engine.
2) By what percentage will a tune-pipe generally increase the engine power.
3) Is tuning a tune-pipe similar to setting up the peak rpm of an engine.
4) How do we know that a tune-pipe has been properly tune-up.

A tuned pipe works basically by bouncing sound waves backwards and forwards. Everytime the wave bounces it changes from a high pressure to a low pressure or from low to high pressure inside the pipe.

1. When the exhaust port opens there's a low pressure in the pipe so the exhaust can escape more easily. This low pressure also draws out some of the fresh mixture into the pipe. Just before the piston comes back up to close the exhaust, a reflected wave gives a high pressure pulse that reverses the direction of the fresh charge that was dragged out into the pipe and pushes it back into the cylinder. This is the supercharging effect and where most of the extra power comes from.

2. This varies depending on the engine and revs etc but for most sport type engine maybe a 10% gain or so. For an all out racing engine it probably at least doubles the HP.

3. Not really, the pipe is usually tuned by adjusting its length to suit the in air revs so it's a bit of trial and error. This isn't a hard and fast rule though, depending on the type of model.

4. Generally speaking, if the pipe's too long (set for revs lower than what the engine's turning) then it's just a giant muffler. Set too short then it tends to overheat the engine. Others with more experience can tell you more about this.

go to www.mecoa.com, they have a whole section on tuning pipes.


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