The other major

contributor is the sonic waves in the exhaust caused by the rapid

opening of the

peripheral exhaust ports.

This may make some cringe, but here goes: what if a small amount of

'ramp' were put in the wall just ahead of the port to allow some gas to
begin exiting, or an inverted V notch. Not enough to make a noticable change
in the exaust timing but just enough to take some of the "pop'" out of the
pressure wave? This may be a subtle acousticle thing. Some people can really
hear the difference between vinyl and CD's. The change of state as the port
opens up is rather abrupt. What about pipe length to collectors tuned not to
augment but to cancel? This may be all pooey... I know nothing in this area.

...Chrissi

You are right on target Chrissi.  This is precisely what Mazda did in the
normally aspirated rotary.  They call them exhaust splitters and you can see
them in all 6 port engine exhaust ports.  They reduce exhaust impulse energy
by 10 db.  That means it reduces the impulse energy to about 1/3 of what it
is in the turbo engine.  Wish I had them in my engines :-(

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com

 
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