Come see what's inside a stock NBS dual inlet/outlet muffler
#1
Thread Starter
On The Tree
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Joined: Jan 2008
Posts: 157
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From: aksarben = Nebraska
Muffler is off 2001, 8.1, 3500hd and looks very similar to the stock muffler on my 2002 Sierra Denali and my moms 2006 Escalade.
8.1 3500HD muffer




The best I can do with what I have!
Inlet Side

Inlet Side Removed

Outlet Side

Outlet Side Removed

Muffler cut in half viewing from outlet towards inlet

Muffler cut in half viewing from inlet towards outlet

View of the Carnage

Everything rotated from the picture above

Muffler Shish Kabob
8.1 3500HD muffer




The best I can do with what I have!
Inlet Side

Inlet Side Removed

Outlet Side

Outlet Side Removed

Muffler cut in half viewing from outlet towards inlet

Muffler cut in half viewing from inlet towards outlet

View of the Carnage

Everything rotated from the picture above

Muffler Shish Kabob
#3
Same here, I like seeing the 'how stuff works' threads. Very interesting design on that muffler. Looks as if one of the inlets passes straight thru and the other inlet passes thru a series of tubes and chambers for sound reduction. I don't know what the purpose of the second outlet in the sealed chamber is though.
#7
Thread Starter
On The Tree
iTrader: (14)
Joined: Jan 2008
Posts: 157
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From: aksarben = Nebraska
This muffler isn’t straight through.
Both inlet pipes shrink down from 2-7/8” to 2” once they enter the muffler.
The 2” inlet pipes pass straight through the first chamber.
The 2” inlet pipes become perforated and pass through the second chamber and dump into the third chamber open ended.
There is a perforated 2” pipe that connects the first and third chambers.
The first, second and third chambers are divided by two bulk heads with four ½” vertical holes and the inlet, outlet and chamber connection pipes passing through.
The one outlet pipe is 2-1/2”, open ended in the first chamber, perforated in the second and third chamber and passes straight through the fourth chamber expanding to 2-7/8” on its way to out.
The fourth chamber is only connected to the Y-pipe in the tail pipe.
Both inlet pipes shrink down from 2-7/8” to 2” once they enter the muffler.
The 2” inlet pipes pass straight through the first chamber.
The 2” inlet pipes become perforated and pass through the second chamber and dump into the third chamber open ended.
There is a perforated 2” pipe that connects the first and third chambers.
The first, second and third chambers are divided by two bulk heads with four ½” vertical holes and the inlet, outlet and chamber connection pipes passing through.
The one outlet pipe is 2-1/2”, open ended in the first chamber, perforated in the second and third chamber and passes straight through the fourth chamber expanding to 2-7/8” on its way to out.
The fourth chamber is only connected to the Y-pipe in the tail pipe.





