Two Stroke Resonance Pipe Tuning

[srp]

On 5/14/2026 at 10:41 PM, gusto said:

Looking forward to learning. Generally speaking can you explain the effects of chamber diameter and cone length ? 

Probably one of the most important aspects of pipe tuning, you’ve read my posts about tuning with effective lengths formulas. An example pipe will make it easier to understand. It takes .265 milliseconds for pressure waves to travel through a header section 47mm (avg) diameter by 200mm long. It also takes .265 milliseconds for pressure waves to travel through a belly section of 110mm diameter by 150mm long. The example pipe shows the header section pressure wave travels 50mm farther than it does in the belly section in the same amount of time. 

Using effective length formulas makes it very easy to time pressure changes in the pipe for resonance tuning. The end of each section will start a return wave to and from the exhaust port. Header and diffuser sections are tuned and timed to be in resonance with the last diffuser, belly and baffle.
 

[gusto]

Awesome.

id love to see what equipment (jigs etc) needed to make a pipe. Curious of templates and matching each side.

thanks for starting this thread

[kawa110]

I wouldn't cut the flywheel for that build, it should rev quick. If all I had was a lightened flywheel I would run it and see how it works.

Finishing the build now, mounted a lightened but can swap to stock…
Thnx


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