I have used the Randy Smith CNC tube muffler with muffler pressure and like the sound a lot. A bit heavier than a tongue muffler, but nowhere near as heavy as the stocker. I drilled & tapped a hole for a DuBro pressure tap, 6-32, I think. You need to put it on the area that's double wall thickness, and that's not all that easy to determine, because the fit & finish is so nice. They sound good, but need a "rubber ducky" to blow some of the exhaust away from the model.

Tongue mufflers have a fairly harsh bark on 'em. A quieter muffler actually lets you relax and fly better, because it just sounds slower. Funny how the brain works.  Steve 

Thanks fo the reply.
So I assume moste people run with the stock muffler with or without muffler pressure OR a pipe?
Thanks,

-Danny

If noise isn't a particular concern, then tongue mufflers are OK.  The main idea is to get exhaust goo out and away from the fuselage.  So why don't they make tongue mufflers long enough to accomplish that?  I quit using them only because they are useless in directing exhaust away.  I'm  much happier with my RE engines, where I can add an extension to exit about 2" below the fuselage bottom.

Floyd

If noise isn't a particular concern, then tongue mufflers are OK.  The main idea is to get exhaust goo out and away from the fuselage.  So why don't they make tongue mufflers long enough to accomplish that?  I quit using them only because they are useless in directing exhaust away.  I'm  much happier with my RE engines, where I can add an extension to exit about 2" below the fuselage bottom.

Floyd

The guiding reason behind the use of a minimalistic and short tongue muffler is weight. The less of the better but .............. they can indeed be made quieter with a longer body and this in turn gets the "goo out and away from the fuselage. "

But I too hate the design unless it approaches at least 6 times the swept volume of the engine - this enlarged volume allows the hot exhaust gases enough room to expand and cool thereby getting the heat away from the engine.

Rear exhaust has to be the ultimate, I agree!

The dubro extension is what i use to make most of my OS tongue mufflers. I can make 2 or 3 , depending on length i need from one $6 extension. Very easy to do by drilling a hole through each side to fit and make an aluminum end cap. Use 2 1/2 or 3 inch bolts with locknuts.  As they come the width fits the la 46. I also cut them in half to remove a little metal and  JB weld back together to fit the la 25. Tap for a pressure fitting if needed.

There is a new MACs controline muffler for the 46LA and others.  Claims to weigh less tha 1.5 ounces.

ttp://www.macspro.com/onepiece.asp#CL

Randy has some really nice tongue mufflers.  Matter of fact, they are the favorites out at our field.  You
won't go wrong with his products and he is down right amazing in his engine knowledge!

IMHO....what Steve Helmick said !

There is a new MACs controline muffler for the 46LA and others.  Claims to weigh less tha 1.5 ounces.

ttp://www.macspro.com/onepiece.asp#CL

http://www.macspro.com/onepiece.asp#CL

The MACS Mufflers are not a bad way to go. I have run them, as has Scott Riese. They do not always fit well with upright or inverted engine installs (tend to interfere with the wing) and often don't fit well on profiles with side mount engines (tending to interfere with the LG legs, unless wing gear or trike).

They also need to hit their tuned rpm, which is probably still 10,200 rpm for the .40/.46. The 11.5 x 4 APC works well for this setup on the .46LA. I would try the 12.25 x 3.75 APC or 12-4 APC on an R/C ST G.51 or Magnum/APC . 46, .53 or .52. The bigger engines may have a lower rpm tuning, but I would call Mac and ask him.  Do NOT add a rubber ducky to one of these. They are a 1/4 wave tuned pipe. If they are at the right rpm, they will sound rather like the wheels are going to fall off.    Steve