I have had an RTF Avistar for about a year now. It's my first RC plane and I had progressed to the point where I was really wanting more power, especially for vertical. So, even though I had a TT 46 available I decided to try a mousse can muffler on a Mac's header. I had read raves about this setup in the Fun Fly forum and I like to tweek things in general so I built one according to the info found on the FF forum. The result blew me away! Much, much more power all around and a very different beast to fly. One good reason to go with the LA is that it is quite a bit lighter than the TT46 or OS 46fx and the Avistar seems to need a lot of tail weight to balance out.

Here's my setup:

1. Mac's header (the one made for a OS 40 FSR). The shape of the exhaust port in the header has to be opened up with a Dremel and metal file to match the shape of the exhaust port on the engine but the bolt pattern is a perfect match. Cut the header length to 3.5" according to the instructions on the Mac's website. This is longer than the length rcommended for the 40fx but the LA is a lower rpm engine (that's my logic). Use the piece you cut off to make the inlet pipe on the mousse can muffler. I also had to stick the header in a vise and bend the pipe down and out a little to clear the wing. I stuck a deep 7/16" socket inside the pipe during this bending to keep from kinking it.

2. APC 10X5 prop although I think a 11X5 is definitely worth trying.

3. 15% nitro fuel

Good luck,

Big Mike