Ben Baltrusaitis wrote:

Does anyone run their 20B without a muffler?
I was told by an engine builder that the sound of the 20B is not as

intense as the 13B and could be run without a muffler. He said the sound was
much like

a

piston V-6.
Thanks!
Ben

Ben If you don't care for your hearing or your airport you could go

unmuffled. (Note that this is a JOKE if there is a language problem)

The rotary is one of the LOUDEST engines you will EVER hear if not

muffled. That includes the 20 B, the housings being close enough to the 13 B
that they are

interchangeable. The three rotor will just have a more continuous

enormously

loud exhaust. Don't plan to run any rotary without at least basic

muffling.

Let me put this in an understandable context. I am an ex-racer and race

car

builder. I have helped build a RX 2 sedan racer back when you could run
most tracks without a muffler. This engine was PAINFUL when wearing foam
earplugs INSIDE my regular earmuffs! Standing in the path of the RX2's
exhaust hurt worse than standing next to a AA Fuel dragster durring a
burnout. The fueler was technically louder (on a DB meter) but the pitch
and timber of the rotary exhaust can be very offensive. DON'T RUN
WITHOUT A MUFFLER. Your ears will thank you for it.
Bill Jepson

-Paul Carey wrote:

Hi Ben
I run a 20B drag car, and can confirm exactly what Bill says. My first
attempt with open headers (2 1/2" pipe about 3 feet long) quickly got be
banned from the track, as it was louder than the Top Fuel Dragster there
that day! I tried Gonzo mufflers, which took the edge off, but choked the
engine. I now have three huge flow through mufflers, one for each housing,
and it is better, but still loud.
PC

Paul Carey LAME, MC
Aero Group Pty Ltd ACN 109 854 015
Aero Management - aviation consultants.
www.aeromanagement.com.au
(08) 9371 5205  0418 959 892

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