I'm pretty close to finishing my plane, just getting the paperwork
assembled for
registration and then inspection.

I was up working on it when one of the other tennants stopped by to
compliment me on the
looks of the metal cowl. He said it looked really nice with a cowl
like
that, but that it
should sound more "Macho". He said it was too quiet, when I'm
running it
all he can hear
is the fan in front.

It's got 2" diameter pipes into a "y" 32 inches back from the exhaust
ports, then into a
Hushpower muffler and then out to the side and bottom under the
wing. It
has the  jspec
13BREW motor with no exhaust port baffles.

The prop is a Catto 74" dia x 88" pitch.

Brian Trubee

I wish there was a way to lower the tone. I am thinking hard on that
problem.

Paul Lamar


5000 W stereo and speakers? :)

Are you still running twin turbo's?  Just wondering with the 13BREW
comment.

Tom

Brian's airplane is NA Tom.

Paul Lamar


It seems like separate stacks, one from each rotor, pointed in
different directions would lower the tone.  It would certainly lower
the frequency of the output pulses.

Then again, I'm not convinced it would be an improvement to lower the
tone.  My opinion is that people aren't used to the sound.  Making it
more big-fart Continental/Lycoming-like isn't better, just familiar.
I think we need to get more people exposed to the smooth and powerful
sound of not reciprocating..

I do think it would be better for the engine to not sound like a two
stroke, which I think some people may unfortunately associate with the
Wankel.


Matt-

I'm pleased with the way it sounds now,  people come out of the
woodwork to see what type of plane is making those engine sounds.
That's not a bad thing. If I wanted it louder, or perhaps try to
reduce the exhaust backpressure, there is a slightly shorter
hushpower muffler available. It remains to be seen how much power
this engine makes, but I believe it is slightly upwards of 190 HP.

Brian Trubee

We can get a 300 watt amp and a speaker and play back recorded
sounds of Lycomings :)

Paul Lamar

Unfortunately, a 300 watt amp won't be enough to compete with the
thousands of watts coming out of the muffler.

Maybe we could introduce a slight phase shift, longer exhaust on one
pipe, shorter on the other, to get the beat frequency desired.  Sort
of Star Wars like...

I would settle for that 4 rotor LeMans sound, to heck with quietness.

Chris Cosman

I don't totally agree 300 watts is LOUD. Perhaps the rotary with out the
muffler is a lot louder as that is about 200 HP or 149,000 watts :)

If you want to hear the 4 rotor listen to this youtube video.
http://www.youtube.com/watch?v=MExeYRiJDVI

Paul Lamar

Brian,


Congratulations on getting there.  Say could you tell me the brand and # of the starter you are using?  It looks compact.


Thanks


Doug