Interesting trivia, at least to me, is that Paul Moller of the
Moller Skycar was also the inventor of the SuperTrapp mufflers. I built
motorcycles and watched the “progress” of the Skycar for years before
I learned of the connection.
Michael McMahon
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Monday, January 05, 2009 7:15 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 20B install issues overcome
At
one point a few months ago I added a SuperTrapp to my existing exhaust just to
see if it would tame it a little. Cost me about 500RPM on the top end with
little or no improvement in the sound output.
-----
Original Message -----
Sent: Monday, January 05,
2009 11:49 AM
Subject: [FlyRotary] Re: 20B
install issues overcome
Earnest,
I believe that the SuperTrapp muffler is an example of a band gap device and it
worked well, if properly tuned.
I think the large block idea has merit too, but you will have to allow enough
thickness to prevent the tubes that see the exhaust first to fight the harmonic
vibration and heat. Different size diamonds in the exhaust stream might also
help fight harmonics.
Bill Jepson
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