Nice looking plane Joe. I see that you are going to make me make another decision though. I don't recall anyone ever showing up with muffler pressure on a 15, I have to check some of the old pictures. I do allow it in Sportsman, and as far as I see there is not much advantage to muffler pressure except some of the newer motors have carbs which need it to idle. And most fliers at the Flyin are Sportsman in 15, so you are probably safe.
John

Nice looking plane Joe. I see that you are going to make me make another decision though. I don't recall anyone ever showing up with muffler pressure on a 15, I have to check some of the old pictures. I do allow it in Sportsman, and as far as I see there is not much advantage to muffler pressure except some of the newer motors have carbs which need it to idle. And most fliers at the Flyin are Sportsman in 15, so you are probably safe.
John

  John, in 2011 I entered a .15 with a muffler at Brodak's. It was the ship that I rebuilt on site after it was run over by a good friends car at the site.. Unfortunately it crashed on takeoff.  Precident set, and I have the video from Tim showing the disaster!
Joe