"muffler mod" Thoughts?
I put a borescope in the tailpipe and found the m157 mufflers are very simple, it appeared the 2.75" pipe enters the muffler, goes though about 6" or so of the sound deadening perforations, then Y's in to the two tips.
I assumed the inside muffler was just packed full of fiberglass and so my plan was to simply close up some or most of the perforations with a clamp and seal it back up. its reversible, tunable (like you can only cover half if you want) and quite unintrusive... but it turned out they are a bit different.
Turns out there is no fiberglass in the majority of the muffler. There is another Y, that simply dumps into the empty cavity with no exit. and then the perforated part of the main pipe are simply covered by a 6" can with fiberglass inside, essentially a internal glasspack. That kinda spoils my plan. Its going to be a lot of cutting to removed that 6" can, and you cant go back. You could completely gut it, and weld in straight pipes inside the muffler, but again, not easy, not reversible, probably too loud.
any other ideas?
Oh well, at least we know what they look like inside now
Last edited by kenneyd; Apr 17, 2021 at 01:54 PM.
I wanted louder so I went with 6" race mufflers with 4.5" quad tips.
My setup:
- Long tube Headers
- No Cats/Resonator
- Double X-Pipes (Gives it that high pitch exotic AMG sound)
- 6" Race Mufflers
- 4.5" Quad Tips
I wanted louder so I went with 6" race mufflers with 4.5" quad tips.
My setup:
- Long tube Headers
- No Cats/Resonator
- Double X-Pipes (Gives it that high pitch exotic AMG sound)
- 6" Race Mufflers
- 4.5" Quad Tips
Nice!, however, for all intents and purposes, the stock mufflers essentially have the exact some thing inside them, just not chrome lol.
I went back and forth on weather or not to continue or not. What the hell, I started cutting up the can, and found the perforated pipe. I have not yet crossed the line of hacking beyond a simple welds to return to stock if i still give up. Im going to just buy a stainless but clamp and put it all back together. I'll report back.
The only problem I see with this, is that the inlet pipe is 2.75 in, however the perforated pipe area is 2.5 in. Not sure why it chokes down right here, maybe it's intentional allowing exhaust flow from the pipe that dumps into the cavity to filter through it? Kind of odd. I wonder what it would sound like would just the fiberglass gone only
Last edited by kenneyd; Apr 17, 2021 at 03:12 PM.




I expect fiddling with the mufflers will change that AMG sound.
I drove the car yesterday simply with just the fiberglass mat removed from one side. Couldn't tell a difference lol




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