Re: Power Flow Exhaust?
Since 2005 on my 1971 C-172L; very satisfied. Its first in-flight use was by the A&P / AI who installed it and ferried the plane to my base. "You're going to like this. She was off the ground considerably sooner than the normal 150 hp O-320. With only a mild breeze at rotation I soon looked at the VSI and it was indicating 1200 fpm. And it's quieter."
Later in that summer a friend was flying the bird, accompanied by his wife and another friend. The day was 80°+ and he later said that "she was climbing at 900 fpm. Nice." I haven't confirmed an alleged 2 gph reduction in fuel burn because most of my flights have been rather short legs with takeoff, landings, and other maneuvers included. Those conditions aren't a good method of checking fuel burn as compared to some long legs.
One of my instructors, at runup, said "May I have the plane?" From there he did the takeoff. "Hmm; off before we got to the windsock. If I had the money I'd put one of these on my plane."
"Yup; and you were off the ground at 50 mph." Needless to say, I like it.
HR