I had the opportunity to hear a renesis motor on a Jabaru yesterday.
   It had
   NO muffler at all and made less noise than a Lyco.  I was expecting
   to be
   deafened but I was extremely impressed with the note.

   I was standing about 12 feet to the side at one point and when the pilot
   revved it up to 4000rpm I was standing at the tail holding it down
   and the
   noise was not overly loud.  The cowls were off at the time so I
   imagine that
   it would be even quieter with them on.

   The white wrapping on the exhaust pipe is some old asbestos wrap.

   Greg


   That exhaust wrap is very dangerous. First; the rotary exhaust
   temperature
   and frequency is higher so it is very hard on metal pipes. Two; it
   is difficult
   to inspect for cracks. Not recommended. We have had a couple
   of crashes for this reason.

   --
   Paul Lamar ...No rotor no motor.

Hey Greg, what prop is that.  Looks ground adjustable at a minimun.  Is
it a warp drive?
BTW, I mostly agree with Paul about the wrap.  Besides it being
ASBESTOS, they are problematic but can be made to work.  You need
something rated to 2000 deg., don't let it cover any welds, and it is
best to have a cerramic coating on the exhaust to minimize corrosion..
Will corrode very quickly under the wrap without the coating.