I understand that tongue mufflers offer less weight and less exhaust gas restriction than conventional mufflers.  Often, additional holes are drilled in tongue mufflers to reduce restriction even further.

From my observations of engines operating with tongue mufflers,  the sound level of the exhaust is hardly less than that of engines running without any mufflerat all.  I'm not sure what the advantage is? 

Perhaps someone can explain.

Thanks,

Joe

I would think the toung muffler directs the sound downward toward the imediate area of the circle. The standard muffler dirests the sound out the back to the surrounding area as it goes arond the circle.

Don McClave and I have been working ON a new/old theory. Don asked me to drill THREE 3/32 Holes in the end of one of my tongue mufflers. We are now seen better engine responce in the 45 and above.
Today we put in twenty flights on his LA-40 and we came up with the conclusion that resonance is reduced and better engine performance is the trade off. I too drilled three holes in my Brodak muffler and YES I too have better overhead grunt. More to come