Anyone tried a Jett Engineering in-cowl muffler? I would like to try one
with an OS91 FX. I have an app where I don't want to hack up the front of
the plane and the cowl to make a traditional muffler fit. Their site
http://www.jettengineering.com/accy/turbo.html indicates they get better
performance with it than the stock OS muffler.