As an example, the PowerPro Series book "How To Build And Modify Intake &
Exhaust Systems" states that the primary purpose of the muffler, of course,
is to "muffle" the exhaust noise levels to an acceptable level. The glass
packs do this by using a perforated pipe going through a casing filled with
a heat-resistant dampening material, such as basalt wool. As the gases pass
across the perforations, the holes set up eddy currents, which tend to
impede flow. In a turbo muffler, the exhaust gases are split upon entry,
sent in two different directions, and brought back together as they pass
through the muffler. When brought back together, any identical frequencies
collide and cancel each other, thus reducing noise without impeding flow (as
with the perforations).
Well, dude, I don't know what else I can tell you. I'm not a muffler
expert, which is why I read quite a bit about them. All I can say is I've
never seen a performance article or book that recommended glass packs over
turbos, and they all recommended exactly the opposite. This includes
performance articles in magazines from the early 80's up thru the late 90's,
so I guess the turbo muffler factories have ALL of the performance writers
snowed, even the ones doing dyno tests.
Take it for what it's worth. I'm just passing along information. I really
don't care what kind of mufflers you put on your vehicle, but I'm sticking
with turbos. Just too much info out there saying they're better......
'92 Dak CC 2wd 318 3.55
'84 GoldWing Interstate
----- Original Message -----
From: John Neff
> OK, now that my question has NOT been answered, I'll ask it again. Why
would
> a glass pack cost you performance and mileage? That was the original
> statement and there were no qualifiers that stated that this was in
regards
> to a Turbo type muffler. A glass pack is just like a Gibson, Magnaflow or
> Mopar (Leach) muffler. It has a perforated pipe going straight through the
> muffler and the sound is absorbed by the material surrounding the
perforated
> pipe. In this case it is fiberglass, in the others it is more akin to
steel
> wool. What makes the Turbo type muffler so superior to a glass pack? How
are
> they different? Could it be that all those articles and performance books
> all came out the back door of the factory that makes turbo mufflers?
>
> John (still confused)
> 98 Dak 4X4 CC Sport, 5.2L, Auto, Leach headers, DDBC
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