Nothing sounds worse to me than a flying chainsaw. A properly designed muffler will not loose rpm over the stock muffler but will make the engine sound smooth, deep and fairly quiet. The best cannister is the JMB, they are extremely quiet, but have a very deep tone. I'm working on a large volume, incowl, baffled muffler. It will not necessarly increase performance but should work in planes not set up for tuned pipes and weigh only 2oz more than a standard pitts muffler. For a tail heavy plane flying at a noise sensitive field it will be perfect.

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I'm in the process of swapping my Brillelli 60 for a new DL-55 from TBM in my EF Yak. With the Brillelli, ES Composites pipe, alluminum header and two 2600Mah Li-Ions, AUW is 18lbs 8oz. The DL is 7oz lighter than the Brillelli and I am changing the fuel tank from a 20 to a 16oz for a total weight reduction of about 11oz. While I agree with Joe that the DL muffler is the lightest option at 3.4oz, my pipe/header combo weighs 10.4oz. I just love the growl and the extra power of the tuned pipe vs the pop-pop-pop sound of a muffler!
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