I recently finished the Aermacci from Modellbau-USA. Although the manual is a bit skimpy on setting up the tail pipe, I asked some fellow modelers on what is the best way to do the install. The consensus was to put some air vent holes in the rear of the fuse to diffuse the heat and to use some BV heat shield in the rear as the heat problem was aknon fact. Well on the first test run before the maiden flight, the engine a P-80 was fired up and some taxi test and ground range with the turbine running were done. The rear of the fuse just behind the turbine was so hot that it softened the fuse epoxy in a few spots. The pipe at this part of the fuse is of single wall construction. The back half of the pipe is dual walled. I made a few calls and was told to put more air holes where the front of the pipe was. I made these in the shape of NACA inlets. I also wrapped ceramic blanket around the pipe in this area also. The second flight was its maiden and it went off without a hitch. After the landing and taxi back, the fuse was just as hot as the first run. In fact it did bubble the paint in a few areas. My next step was to obtain a double wall pipe from Tamjets at the recommendation of Todd Witkoff. I installed the pipe and brought the Macci to a friends house to test is effectiveness. Just after assembling it the rain came so the test was off that day. I left all in the friends garage. Next day went back to do the test on the pipe but noticed that the seam from the canopy to the fin had separated and was split open. Not wanting give up I taped the seam tightly and we fired up the turbine with the new pipe. Needless to say it sure solved the heat problem. I asked Modellbau why they did not use a dual wall pipe. Answer was to save weight. I did get a new fuse from them and am awaiting the next flight and hopeflully many more after that.

I too have the same plane, but found several changes had to be made to it. I have the T-750 engine and their tail-pipe, had to make a bracket for the pipe where the engine went into it, seems it moves when you go to full power, after that fix the heat was no problem with the test starts I did, but that was with the wing off! Air flow for this model is a problem, from those I've talked to, heat is going to be an issue no matter what! Don't know that for sure, will when I get the plane in the air. Let me know what you find out! Thanks
Tomcat