Agreed. My turbo does quiet my rotary down a lot, however, I would not consider it quiet. This was reinforced the other day when my buddy Blaine started up his RV-7 with an Eggenfelder Subaru with essentially the same
prop I have (IVO three blade...his is longer than my pusher) and his engine was so quiet when I pulled up I did not hear it from the street. about 30 feet away. This was at idle.
Hmmmmm? what about a small muffler after the turbo?? ;-)
Chris
From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Al Gietzen [ALVentures@cox.net]
Sent: Wednesday, April 20, 2011 7:56 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Tangential Muffler
If you're running a turbo you shouldn't need a muffler. The turbo serves the purpose of the muffler.
Mark
A turbo helps, but listen on this video to my 20B and
Dave’s 13b turbo,
and Mike’s 13B NA with some other kind of muffler.
http://www.youtube.com/watch?v=dibuqenWcOk
(Courtesy of Paul Lamar. He did sound measurements and mine was the quietest)