I put them on my B-25 last winter. Only got to try the engines once but the sound level seemed okay.

Steve and I talked about them last year...... have to see if they take enough of the bark off..

sometimes it doesn't take much. When I flew my Giles with the Moki, there was quite a snap, almost tinny. Then I remembered the "early" days when we used to put old bicycle inner tube pieces over the "mufflers".

I painted the big Pitts muffler with red gasket material and took 3 Db's off the noise level..the noise was from the thin muffler material rather than the exhaust...