simon1966

Thanks Mullet - this is the exact info I need. I will now definitely not remove all the pipes in the main chamber. I actually had the same thoughts (see post 16) about sleeving or replacing the perforated sections of pipe.

As posted I'm now thinking that just cutting out the inlet as it comes into the small chamber and closing off the u bend will effectively result in a straight through design but with some sound deadening from the perforated straight pipes that connect to the tips. I wish someone had some pics of the small chamber as I assuming it's just empty

Lawrence1

that would be fine ... i want to make sure i do this right and your way sounds like something that wouldn't sound too wild.

simon1966

Looks like I'm probably going to have to wait a couple of weeks before I can get the boxes opened up.

In the meantime has anyone opened the small chamber up and any thoughts on what I'm proposing?

chiromikey

I think having the perforated sections allows the pulse wave to leave the u-bend and enter the exit tube out of phase with the pulse wave traveling through the tube. This could be an important part of the noise canceling properties of the muffler. If you sleeve or use solid tubes you might end up with a lot of drone that the design eliminated.

simon1966

Thanks - I'm now thinking of totally leaving the main chamber untouched and not even opening it up, but instead opening up the small chamber and cutting out the inlet so that it just discharges into the small chamber. The plan then would be to get the u-bend totally blanked off from the small chamber making it redundant. Therefore the exhaust gases would simply flow out through the straight(ish) pipes to the tips. In my mind this will effectively result in a straight through design but with some sound deadening from the perforated straight pipes as they pass through the main chamber

See schematic sketch.

Thoughts??

FromM3toAMG

I don't understand why people don't just buy exhaust. Why ghetto rig it?...

simon1966

What would you suggest? I like the idea of CLS55 or C63 mufflers, but very difficult to get here in the UK.

I had a quote for Eisenmann, but $3300, is way too steep just for mufflers!

stockC43

Lets face it. E55's are in the low teens now and as low as $9k at auction now. Why not try to mod the muffler for free if you can and it works. C5 corvette guys have been doing it for years. Google c5 muffler bypass. Did it on my c5 with long tubes and no cats. It sounded perfect and cost $5. I'm not going to spend thousands on a muffler for car I paid less than $13k for. So, is a resonator delete considered ghetto also?

Simon, I'll see if I can cut mine open this week. I should have some time. I'll post pix of the small chamber with before/after vids. Hopefully it doesn't end in failure. Worst case, I weld the piece back in and return it back to stock.

FromM3toAMG

I don't think the price of the car matters. Resonator delete is not ghetto, in my opinion gutting mufflers is like heating/cutting springs. I have never heard a gutted muffler that sounded good. It seems to always sound like a coffee can.

Personally, I would suggest finding a C63/E63/CLS63 muffler.

stockC43

I agree, I don't want the hollow coffee can sound either. That's the main reason I don't want to remove the wool insulation or cut out the pipes in the main chamber. I just want the exhaust to make less passes through the muffler. All of the amg mufflers are basicly constructed the same and with the same meterials. The only difference being the amount of perforations, distance traveled in the perforated pipes and the size of the chamber. If I can make the exhaust travel half the distance through the perforated pipes, in theory should be just like a c63 muffler. Worst comes to worst I ruin a worthless muffler and just get some 63 mufflers.

simon1966

Agreed I would prefer to find some different mufflers but as said not an easy task over here, I'm sure there are more available your side of the pond. From what I've read and I could be wrong, the the c63, sl55, cls55 mufflers are pretty much straight through designs with perforated pipes and lagging around them. The e55 seems much more complex probably to quieten it to what would be considered luxury rather than sporty. I don't want it like a coffee can, I just want it a little more vocal in a good way.

simon1966

Thanks stockC43, we obviously have similar thoughts and would be really interested on your findings. Seems strange that this route doesn't seem to have been considered, but there could be good reason for it!

I have spoken with a local exhaust shop and they couldn't do anything on the mufflers until next week, but I won't have my car as it's already booked in for other service works hence why I can't look at this for a couple of weeks now.

stockC43

Work in progress. Wi it work? Who knows. I can only do the left side at the moment as I don't want to drop the whole exhaust at my house w/o a lift. I'll do that at work later, if this works.

Weld ground off around the edge to minimize cuts










I'll update later as I go.

chiromikey

Gutted E55 mufflers sound pretty good. The fact that there's ZERO drone makes them a better option than aftermarket imho.

stockC43

Well, the one muffler is done and I think it sounds pretty damn good. it doesn't sound hollow at all like a flowmaster. It sounds like I assume a 63 muffler sounds like on a 55. You can hear a little burble and pop like a 63 but a 55 will never sound like a 63 though unfortunately. Keep in mind that I only did the left muffler right now until I get it on the lift. I have stock manifolds, all 4 cats and a res delete. I can't drive it at the moment though, I'm doing new xenon projector lenses so the front end is apart. Lol, too many projects at once. Hopefully I can have some gopro vids driving this weekend.

I left a little bit of the bend in place to keep the reinforcement of the pipe to the muffler in place. It's not affecting flow at all. And yes, my tig welds look like poo. I was down to my last bit of tungsten and it was contaminated.




Just some crappy iPhone vids.
For some reason the audio went quiet before the rev so I made a second vid.

http://i3.photobucket.com/albums/y79...ps2662815c.mp4

http://i3.photobucket.com/albums/y79...ps2fb83124.mp4

chiromikey

Looking forward to your feedback, especially drone at freeway speeds.

simon1966

stockC43 - well done, nice work That's pretty much exactly what I was hoping would be inside them.

Good idea grinding the welds rather than just cutting the case too. So far I think it sounds great Thanks for taking the time with all the pics etc, very informative.

Keep me posted - Cheers.

austingtir

Well I weld for a living so to me it makes no sense whatsoever to pay someone 3k for a pair of mufflers that i could actually make nicer myself if i could be bothered (which i honestly cant be, id sooner custom make a set of headers for it than the rear mufflers).

This will cost me next to nothing and get the desired result im after which is not a major increase in noise. I just want mine to sound similar to a cls55/63.

For what i want cutting the front chamber and removing the single piece that joins into the U bend makes the most sense to me so thats what im going to do.

austingtir

Someone needs to hunt down some wrecked c63/cls63 mufflers and cut them open to see what they did. That is the obvious thing to me to figure out how to get the closest sound to the expensive second hand ones.

The next step to me is to cap the ubend as StockC43 has done but i would drill holes in those caps at a smaller diameter than the twin exit pipes....... This allows it to resonate properly into the other chamber but still hopefully flow a bit better out the twin pipes..... id hope....

actually i have some stamped mesh 3mm plate like the round pipe they have used at work.... i just had an even better idea use that to cap the U bend.

simon1966

Agreed - This is what we really need to see, some c63, cls55 or cls63 mufflers opened up to see what they are like inside. Stock C43 and I have had pretty similar thoughts on what to do here and he has done it, so hats off to him for making it happen. I like the idea of what you have said about maybe some small holes or mesh in the capped pipes to help resonation, or maybe this would dilute the sound too much

simon1966

Unfortunately I have no facilities or skills to do this myself so will have to take it into the exhaust shop to do it for me. How long did this take to do?

stockC43

Oh great, please don't look too close at my welds. Probably some of the worst tig welding I have ever done. I wouldn't of posted the pix but people needed to see them.





I thought about that too and may be another route to go. Your way might help with drone, if it does. Not sure yet. I think even if you cut open the bend and leave them uncapped it should increase noise considerably at wot due to exhaust taking the path of least reactance.

simon1966

Any updates on these mods guys?

austingtir - did you manage to do the version you were suggesting by leaving the u-bend open or capping it with perforated plate?

stockC43

I finished the other side over the weekend and it sounds good. I would say its about as loud as a G55 kompressor but more balenced. Less side pipie sounding. Maybe slk55 like? Noticeable but not loud engine noise on the highway but not what I would consider drone. About as loud as tires on a concrete highway. It has a low tone, not hollow or tinny sounding. Overall I'm very happy with this mod. I didnt want something too loud as it is my daily driver. Only downside is that my fuel econmy is down due to me revving it out to 3k from the stop lights because it sounds so good.

I'll try to get some gopro vids up soon.

simon1966

Hi stockC43

Great, thanks for posting, I'm hoping to get this or something very similar done to mine next week. Looking forward to the vids, looks like we may have found a new and better way forward with modding these rear boxes