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Gurus - enlighten me please

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I've had ideas for 250cc 2-stroke muffler designs rolling around in my head (amongst the cobwebs & rocks) for years, and I would love some professional (and non-professional) input. Just fodder on breaking up sound waves.

1) Dual-core: I assumed that the over-all length of the exhaust stinger & perforated core help determine the powerband. Typical thought processes would determine a smaller core might help with throttle response, but choke off top end, and vice versa with a larger core.

Why not two wrapped, perforated cores of different diameter

(ex. 80cc & 125cc muffler cores) within the same muffler?

Where the stinger enters the muffler, a "Y" section of pipe diverts - almost straight - into the 80 cc core, while facing downward & then parallel it flows into the 125 cc core. The past of least resistance is directly in-line of sight with the smaller core, and that one would handle the majority of flow at lower RPM's - until additional flow is required for higher RPM's, and the larger core would handle the additional load.

If the total volume of the 2 cores is comparative equal to that of the 250 cc core, conventional wisdom would suggest that power delivery would be similar. As far as the terminus, those 2 cores flow back into another "Y" to a single outlet with a turn-down tip, OR - empty into a "dead zone" chamber (similar to a chambered Flowmaster muffler) where the last couple of inches of muffler housing had no core, but had packing around the dead-zone chamber.

If you are having trouble visualizing that last piece - industrial pipe insulation is fiberglass supported by wire mesh. Trimmed & inserted in the "dead zone", it would add a 1/2" thick layer of sound deadening prior to the end cap. It's an old hot rodders trick for side pipes to knock down a few more decibels.

2) An auger style insert like these http://www.speedwaymotors.com/Speedway-Auger-Style-Muffler,1736.html

... possibly with a small perforated core center ala Car Chemistry inserts http://www.carchemistry.com/shop/index.php?l=product_list&c=76

3)A coiled-tube core. If a core were coiled, and the outer face drilled & the assy. packed, a generous amount of sound absorption surface area in a relatively small space.

Combinations could theoretically work as well.

I'm thru typing now...

GT

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I built a chambered Flowmaster-type silencer for a 94-02 KX250. Lost the pics I had, but I still have the silencer. Most of the noise from a 2 stroke generates from the pipe. A Q silencer, along with a wrapped pipe with a guard will give you a stealthy bike.

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I see the E-Line pipe guard for the 2003> KX's

Any clue how well they will fit a slightly older model?

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