[colorado.e9x]

I have a thread for how I did mine. I wish I didn't fill every hole though I can't say I'm dissapointed about the outcome either

[bluewater328]

Need someone to do this for me :P

[Alexvier]

Originally Posted by nikg736

I am absolutely dying to know...how does one weld the underside of the tubes within the muffler with only the top of the muffler shell cut off? There is not way to get to the bottom to weld it.

Originally Posted by nikg736

I am absolutely dying to know...how does one weld the underside of the tubes within the muffler with only the top of the muffler shell cut off? There is not way to get to the bottom to weld it.

You don't need to bother as the PE is perforated inside to as the image above denotes just like the 330 exhaust. Seal it as good as you can. As there is also perforations in the centre baffle too.

[The Nightman]

Originally Posted by neilvan

I actually haven't opened the 330i ; we just swapped the 330i exhaust resonator back onto my brothers 328i. Actually made a decent difference although secondary cat delete is next.

Here is another image I found. It actually seems closer to the PE than to the 328 ones.

FB_IMG_1607784362939

Very cool find. 15 years on and we're still learning new things. The 330i with the valve open does sound like a nice balance between the stock 328i and PE exhaust:

[neilvan]

Originally Posted by freedomfries

Very cool find. 15 years on and we're still learning new things. The 330i with the valve open does sound like a nice balance between the stock 328i and PE exhaust:

My brother had a secondary cat delete done now with the 330 exhaust and its very oem+. I don't believe its as crackly as the video posted; some euro countries had no secondary cars+ a smaller cat in the header due to different emissions.

The car has sound and a personality without telling everyone you have an exhaust; and 0 drone. You really notice the difference when you put it side by side with a stock 328(which really is just silent). Plus the 330 resonator back is a larger diameter so you get the performance benefit

[nikg736]

This may sound crazy, but has anybody attempted to modify a stock exhaust with an internal butterfly to go from stock to "performance"?
The reason I ask is because I was considering doing an electric exhaust cutout valve that would run the exhaust through the stock muffler when closed and essentially be a muffler delete when open. But in North Carolina they dont allow cutouts and it will fail inspection.
I like the idea of having a totally stock exhaust when I want it quiet (long trips, highway, on my way home from work when I have a headache), but I also want the option of more aggressive sound. Not looking for performance or power, just something other than totally silent
So...if I could somehow have an internal butterfly in a stock muffler to go from stock to bypass then that would be perfect. Problem is...not sure if it could be pulled off.
Any ideas?

[colorado.e9x]

Originally Posted by nikg736

This may sound crazy, but has anybody attempted to modify a stock exhaust with an internal butterfly to go from stock to "performance"?
The reason I ask is because I was considering doing an electric exhaust cutout valve that would run the exhaust through the stock muffler when closed and essentially be a muffler delete when open. But in North Carolina they dont allow cutouts and it will fail inspection.
I like the idea of having a totally stock exhaust when I want it quiet (long trips, highway, on my way home from work when I have a headache), but I also want the option of more aggressive sound. Not looking for performance or power, just something other than totally silent
So...if I could somehow have an internal butterfly in a stock muffler to go from stock to bypass then that would be perfect. Problem is...not sure if it could be pulled off.
Any ideas?

Anything is possible. My idea revolves more around the E82 mufflers just because its easier to work with though you could totally adapt an E9X muffler to do the same.

Have the inner (right) pipe be stock, no modifications. The outer pipe would be welded up to be completely straight through all the way to the inlet. You can place the butterfly valve somewhere along the pipe. I'd imagine near the elbow before the exit or in the center portion would have enough room. Then just make sure any plastics or wires have good heat insulation, drill a hole through the shell, pop in a grommet to make it as water tight as possible, and run the wiring through the trunk. If all that works a quick disconnect in the wiring wouldn't be a bad idea in the event you need to remove your exhaust down the line.

This is all in theory and I'm honestly 50/50 that it'd work well over time. There are other considerations such as if its wireless (youd be basically encasing it in a faraday cage) and if you could do all of this with only opening the top of the shell. I'm not sure if inspection would like it if they saw a weld in the middle of your muffler

[nikg736]

colorado.e9x -- that's kind of what I was thinking. But I was concerned that having exhaust flow through just a single outlet at a time would back up the system too much. Maybe not enough flow. Perhaps replace the stock tips with larger (maybe 3") and that would provide plenty of exhaust flow.
I too am wondering what they look for with inspections. I think if all cuts and welds were on the top and wire ran out the top of the muffler that nobody would even notice. Maybe?

[colorado.e9x]

Originally Posted by nikg736

colorado.e9x -- that's kind of what I was thinking. But I was concerned that having exhaust flow through just a single outlet at a time would back up the system too much. Maybe not enough flow. Perhaps replace the stock tips with larger (maybe 3") and that would provide plenty of exhaust flow.
I too am wondering what they look for with inspections. I think if all cuts and welds were on the top and wire ran out the top of the muffler that nobody would even notice. Maybe?

Stock 328 tips are ugly anyways so might as well haha. I think you'd be fine honestly, if you look at any truck or suv older than 2006 youll probably notice their exhaust pipes (coming from a V8) are tiny single exits. But yeah if you're worried about it you could make them (and any other piping the same diameter) bigger. As far as inspections that's what I'd do if I decided to take on this project, do everything from the top

I'm really curious to see if this can be pulled off

[nikg736]

I might be able to get a muffler for real cheap (like $20) from a local salvage yard. If that is the case then I might buy one, cut it open and start looking at the possibilities. If the plan goes all to crap then very little money wasted. Wasted time? Heck, cutting, welding etc. is never a waste of my time. I dont get nearly enough opportunity to play with my metal fab toys as it is.

[nikg736]

So I decided against modifying a stock muffler and bought a Magnaflow 11148 instead. I am going to do the install myself. Does anybody know the diameter of the internal tubes of the stock muffler? Looks like a nice source of mandrel bends. If the internal tubes match the exhaust exits then I might just buy a junk one for $20 to get the $80 worth of stainless mandrel bends inside. That way I also have extras in case I screw something up or decide maybe to go with a different muffler in the future.

[Alexvier]

Out of control

[drummr8]

Originally Posted by TylerJamesInc

Thanks to this thread, I recently reworked my "N52"(actually an N51, so I can't call it an N52 in good conscience) muffler.
I took a different approach than I've seen anyone else take, and the results are fantastic!
After cutting open the casing, I came up with my plan. I then cut the two ~1.75" tailpipe 90's out, and removed the tailpipes altogether.
I got a 3" 90*, and a 2.25" 180* mandrel bend from a local exhaust supply shop to make my new routing.
I'll let the pics speak for themselves, but it tuned out great. To be clear- all the packing went back in. The new routing is very simple- the 2.75" inlet comes in, goes through the perforated/packed section once, and goes through a custom 3" to dual 2.25" tailpipe y. The 3" worked perfect to slip over the 2.75" lip where it exits the packing chamber, and also wasn't difficult to flatten in order to transition well to the 2.25" y. As you can see, I cut open WAY more than I needed to. My original plan was to try to clone the PE more closely, but after looking at how much fabrication work that would be, I came up with a much easier(and better, IMO) method. If you follow my method, you only need to cut open the tailpipe-side chamber.
2.25" to 3" stainless single wall tips are damn near impossible to find, so I got two rolled edge tips, and cut them to my liking.
Hope this helps a member- or two- with their own N52 muffler chop.
Enjoy!

does anyone know approximately what this should cost at a muffler shop? I already removed the muffler and bought some tips... going to ask for some quotes next but I'm curious what others have paid. Thanks!

[AmuroRay]

Originally Posted by drummr8

does anyone know approximately what this should cost at a muffler shop? I already removed the muffler and bought some tips... going to ask for some quotes next but I'm curious what others have paid. Thanks!

just buy a 3"inlet Mangnaflow muffler. It will flow better.