BMW M5 Forum and M6 Forums banner
1 - 20 of 32 Posts

·
Registered
Joined
·
82 Posts
Discussion Starter · #1 ·
Has anyone else done this? After selling my aftermarket mufflers I got bored with the stock mufflers. I looked for cheaper than $1000 options and didn't find any. I got to thinking of gutting 2 of the 4 mufflers on the car. I searched and didn't find any info on what the insides of the stock exhaust looks like. I said WTH, I'll just find out for myself. This is what I found:


I took out the packing and welded it back up. It was still pretty quiet. I couldn't even tell that I did anything. Googled some stuff and found the vette guys gutting there mufflers of packing and welding up the perforated pipe. So once again I cut open my cans; this time closing up the pipes. At idle and regular driving the car doesn't sound much louder, but when you go WOT or it's getting revved the sound is pretty amazing. For a "free" mod, I can't complain. It's basically like doing half a muffler delete mod but retaining the stock muffler look. I think keeping 2 of the 4 mufflers stock helped it not drone like my eisenmann race use to at highway cruising speeds.

I didn't weld my pipes up like they did in the link. I read some of the zo6 guys using hose clamps with success, so I went ahead and did it that way. In case I want it quiet again one day I wont have to do much but cut it open and take the clamps off.
 

·
Registered
Joined
·
82 Posts
Discussion Starter · #5 ·
Yes the perforated pipe runs straight through.
I don't know why they are so heavy. The packing was pretty thick, it cut like it was a solid mass. When I took out the packing it didn't seem like it made the mufflers any lighter. There was about 3 grocery bags full of packing that I took out of the 2 mufflers I gutted.
 

·
Registered
Joined
·
797 Posts
Great idea! I'd love to hear it too.
 

·
Registered
Joined
·
1,531 Posts
Why not just cut the muffler off and weld a straight pipe in it's place? That's pretty much what you've done, but still with the extra weight.
 

·
Registered
Joined
·
82 Posts
Discussion Starter · #9 ·
Because I still retain 2 stock mufflers. If I wanted to cut off the mufflers and run straight pipes I would have done so...

If you meant why I didn't cut off one muffler and weld a straight pipe in it's place... I'm almost certain I wouldn't be able to position the tips correctly.
 

·
Registered
Joined
·
2,594 Posts
blackwagon,

I like what you did & thats a good idea. I'm sure she make more sound then a pure stock system does. And, when you weld the cans back up, no one will ever know that car was modified. This is a good alternative for those that don't want to do straight pipes & worry about new aligning new tips & getting their height/spacing all adjusted correctly...
 

·
Registered
Joined
·
1,478 Posts
I have heard from a number of good sources that the main contributor to drone on the E39 is due to removing the resonator. Most muffler mods, options, deletes really only impact exhaust tone and throatiness and overall loudness or volume.

Can't say I have first hand experience other than my car has Dinan headers and exhaust with the stock resonator and Cats (which is the "full" Dinan exhaust) and I have no noticeable highway drone, even with 3:45 rear gears.

I am sure many of the X-pipe crowd can chime in as well?
 

·
Registered
Joined
·
3,969 Posts
yes removing the resonator has the biggest effect on drone but not limited to. certain mufflers will drone as well. magnaflows for example with the stock resonator in place drone something awful.
 

·
Registered
Joined
·
1,531 Posts
this is a just asking for drone mod, you're creating a large empty space for sound to bounce around in.
He welded up the perforated core, so the sound isn't bouncing around. It's essentially a straight pipe.
 

·
Premium Member
Joined
·
13,589 Posts
I have heard from a number of good sources that the main contributor to drone on the E39 is due to removing the resonator. Most muffler mods, options, deletes really only impact exhaust tone and throatiness and overall loudness or volume.

Can't say I have first hand experience other than my car has Dinan headers and exhaust with the stock resonator and Cats (which is the "full" Dinan exhaust) and I have no noticeable highway drone, even with 3:45 rear gears.

I am sure many of the X-pipe crowd can chime in as well?
Remove your resonnator, and it will drone a little.

yes removing the resonator has the biggest effect on drone but not limited to. certain mufflers will drone as well. magnaflows for example with the stock resonator in place drone something awful.
You should come take a ride in my car...108dB at 70mph cruise ouich
 

·
Registered
Joined
·
82 Posts
Discussion Starter · #16 ·
this is a just asking for drone mod, you're creating a large empty space for sound to bounce around in.
If you look at the way the stock mufflers are setup you'll see why I think this doesn't cause drone. I left one of the mufflers stock, and gutted and closed the perforations on the other. I'm no physics major, but in my mind the exhaust flows through both mufflers at regular throttle pretty evenly; when you go WOT the gasses flow out the closed pipe more than the perforated one due to it's freer flowing path.


In the picture the one I cut open and modded would be the bottom muffler. That would be the two mufflers towards the middle of the car.
 

·
Premium Member
Joined
·
13,589 Posts
1 - 20 of 32 Posts
Top