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Discussion Starter #1 (Edited)
I was curious how our stock mufflers where built, so i decided to gutt mine and see how it performs.
This is how i did it.

Trace around heat shield with blue painters tape. snip the metal straps that hold the heat shield. Cut an "H" in the top of the muffler and drill out the spot welds.

Open up the two "doors"

Note the fiberglass GM uses to muffel the sound.

Remove fiberglass packing.



Remove the louvered baffles/ cores.





Close up the doors and fillet weld all of the holes/large gaps between doors. weld all seams. check/inspect for leaks.
Spot weld the heat shield back on. it covers all of the cutting/welding that i did for a stealth look, looks 100% stock.


SOUND: it dosent sound nearly as loud as i thought it would. it has a chambered sound to it and all of the pops and crackles in the exhaust note are amplified. There is almost no "drone" or interior resonance.


PERFORMANCE: theoreticly it has to flow better than stock because i eliminated all of the bends and hard turns that the gas had to make in the original muffler. but its hard to tell if it did anything at all.
 
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I might be wrong but I think thats going to cause major turbulence(sp?) and hurt performance. On the other hand I bet its loud. Thanks for the pics man
That's what I was thinking too but if you look at the ass-tastic oem design you can probably bet that its going to do nothing but flow better than it did stock...
 

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Discussion Starter #4
i was thinking about turbulence as well... i was even considering reusing one of those louvered tubes to directly connect the inlet and outlet, but decided against it.
 

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yeah bad idea. should run a pipe between em at least..



man i wondered why there was horrible flow stock
 

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Discussion Starter #7
im prob gonna end up doin the straight pipe thing. i was realy just curious about how its made and figured i would try it out for a while... the straight pipe is gonna have a much higher pitched sound too though.
 

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got that 3in cat back exhaust from heartthrob.. its has a nice sound.. loving it right now
 

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hey i have my stock muffler anybody want it.. let me know.. its about to got in the dumbster next week...
 

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yeah .. i figure someone would want to mess with it
 

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I might be wrong but I think thats going to cause major turbulence(sp?) and hurt performance. On the other hand I bet its loud. Thanks for the pics man
It think it causes too much turbulence. Definately not good. For the time it took you could of spent a little money and gotten a performance muffler and replace yours w/ that.
 

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Discussion Starter #14
i just wanted to see how it was made... im gonna switch it out with a stainless steel glasspack someday...
 

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first "cheesebox" mod it. im just curious. we did it to a buddies ford contour back in high school. sounded like shit but was funny at the time.
 

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Right on for those pics, that stock muffler looks sooo fuckin restrictive its crazy. Flowmaster isn't a whole lot better than that either.
 
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