It seems to me that the power loss with a diverter is not necessarily a given when using a diverter. Rather its in the design of the diverter. If the diverter serves to restrict the exhaust flow, then it will rob some power. However, if your diverter area was 2 or 3 times the area of the exhaust outlet, then I would think you could use one successfully with very llittle if any noticeable power loss.

One product that I have not used personally, but gets good comments when someone mentions it is the stuff at http://www.flyquiet.com . They are intended for noise, but would serve well as an exhaust diverter.

Duke