[Hotter]

Originally Posted by neilvan

No one knows what's inside of the NA PE muffler; I've only seen pics of the euro one but I cant see them being too much different.

My guess is its just laws/regulations that allowed what BMW could legally sell. The Euro PE sounds very similar to the PE mod mufflers Ive heard whereas the NA PE is louder and way more pops/bangs/rasp

NA PE muffler with stock 328i mid-pipe is very quite, just with better note, if windows closed you could hardly say if its PE or Regular stock 330i exhaust... I must get mid-pipe without resonator or something!

[eljay]

Originally Posted by neilvan

BMW has those for replacement parts. Factory exhausts(downpipe/header back) are 1 piece but replacements come in sections.

That makes sense! Thanks

[warasaurus]

The 328i is 2.5" stock, re: most aftermarket cat-back bolt on applications such as the Magna-flow Performance Series, reference direct fit 2.5" tubing to muffler with a 3" exit (exhaust tips) I also just modified (this week) a 328i with muffler delete and reroute of 2.5" tubing to a dual 3" tip.

[CTinline-six]

Originally Posted by warasaurus

The 328i is 2.5" stock, re: most aftermarket cat-back bolt on applications such as the Magna-flow Performance Series, reference direct fit 2.5" tubing to muffler with a 3" exit (exhaust tips) I also just modified (this week) a 328i with muffler delete and reroute of 2.5" tubing to a dual 3" tip.

Yep they are 2.5" stock with N52, the pipe is a bit larger with N51.

I have the 330 exhaust waiting to go on my car, will do a video comparison when it does. The exhaust shop I use is pretty booked with appointments.

[CTinline-six]

So I installed a used 330i muffler on my N51 328i. Got the muffler for cheap on ebay, and it was actually in better shape than my OEM muffler. All the shop had to do was cut the old one off, and weld the 330i muffler on. Very simple swap with one weld, and the rest of the exhaust is stock. I don't really want to mess with any of the other stuff because the factory exhaust is more corrosion resistant compared to any of the aluminized crap the muffler shops will have.

Keep in mind the only mods I have done to the car are a Euro intake box (deletes charcoal filter) and a Mishimoto silicone intake tube. Since the 328i doesn't have the vacuum hose for the 330i muffler flap, the flap defaults to the open position.

I'm trying to get a better mic, because the sound difference isn't very noticeable on camera. I will say I think the sound is perfect now. Very OEM+, a slight rumble on start-up, and a tiny bit deeper note when pulling away from a stop. Not noticeable on the highway. It isn't loud by any means, but definitely noticeable over the silent 328i muffler.

[2one3E90]

Anyone cut open the 330i muffler yet?

[neilvan]

Originally Posted by 2one3E90

Anyone cut open the 330i muffler yet?

Post #8 in this thread has it. Shows: 328i, 330i, then PE(euro version due to baffle)

[2one3E90]

Originally Posted by neilvan

Post #8 in this thread has it. Shows: 328i, 330i, then PE(euro version due to baffle)

dude 330i and M performance are similar. Whats the difference? Looks the same

[neilvan]

Originally Posted by 2one3E90

dude 330i and M performance are similar. What's the difference? Looks the same

They share a similar flow path but the differences are pretty clear in the pictures; and obviously in the sounds they both make.

That being said a PE mod to the 330 one would be fairly easy to do

[Tamers]

did you remove the catalyzer?

[The Nightman]

For those who have this done, how accurate is the above video (after 2:30 and ignoring the cold start revs)? It's the only decent video I could find with an N52 330i with the exhaust tip flap always open.

[neilvan]

The sound/volume is about right but there's no crackles (even with secondaries removed).

My guess is the different euro exhaust manifold(shorty header and smaller cat) or the muffler internally might actually be slightly different for euro regulations

[e90lorkp]

Originally Posted by neilvan

They share a similar flow path but the differences are pretty clear in the pictures; and obviously in the sounds they both make.

That being said a PE mod to the 330 one would be fairly easy to do

I have a 330i muffler that I'd like to mod to be more like the PE. How would you do it?

[2one3E90]

just got a stock 330i muffler for 20 bucks. Ima open it up and see what i can play with to make it sound more nicer. I have just supersprint section 2 and stock res on my 330i

[2one3E90]

if you cut the muffler open to mess with the insides is it hard for a muffler shop to weld it back properly?

[The Nightman]

Originally Posted by neilvan

The sound/volume is about right but there's no crackles (even with secondaries removed).

My guess is the different euro exhaust manifold(shorty header and smaller cat) or the muffler internally might actually be slightly different for euro regulations

Thanks! FYI - your inbox is full.

Is there any reason why I couldn't slap a 330i muffler on with a 2.5" to 2.75" adapter? It would make life a lot easier!

[neilvan]

Originally Posted by Guy Fieri

Thanks! FYI - your inbox is full.

Is there any reason why I couldn't slap a 330i muffler on with a 2.5" to 2.75" adapter? It would make life a lot easier!

After some looking apparently the early 330s were 2.75 and the later ones moved to 2.5 to match the rest. Id double check the diameter of the 330 muffler that you have (mine was 100% 2.75" in multiple places).

the 330s also have a slightly different bend in it so its routing is just off. This may be because of the bigger diameter or just a straighter path(performance).

Either way any muffler shop should be able to adapt it with a bit of pipe

[The Nightman]

I ended up finding an exhaust from a 2006 E90 330i. The resonator inlets are 55mm OD, the piping between the resonator and muffler is 70mm OD and the muffler outlets are 55mm to 65mm OD where the tips mount. The part numbers on the muffler don't seem to correspond to anything in RealOEM.

I had the wrecker cut the exhaust just after the secondary cats, as that seemed like the best area to use couplers to connect the exhaust. I plan on using 55mm Torca 409 stainless couplers sold by Walker (#36535).

https://www.normaamericasds.com/product/96-0139
https://www.walkerexhaust.com/conten...r%20Clamps.pdf

[The Nightman]

As an aside, I thought it was interesting how other markets do not have secondary cats. I wonder if that contributes to the higher 200kw (268bhp/272ps) output rating on some N52s?

UK 330i N52: https://i.ebayimg.com/images/g/OPEAA...-n/s-l1600.jpg
South Africa 330i N52: https://www.bmwfanatics.co.za/thread.../#post-1118687

[neilvan]

That is exactly what we did to my brothers car; We deleted the secondaries just shortly after.

I believe we had PA5 emissions and some euro had PA4 (PA4 is no secondaries and the exhaust manifold/headers have a shorty tubular vs a log and a smaller main cat converter).

I also knew I wasn't completely insane by his being 2.75" between the res and muffler vs 2.5"

[CTinline-six]

Originally Posted by Guy Fieri

As an aside, I thought it was interesting how other markets do not have secondary cats. I wonder if that contributes to the higher 200kw (268bhp/272ps) output rating on some N52s?

UK 330i N52: https://i.ebayimg.com/images/g/OPEAA...-n/s-l1600.jpg
South Africa 330i N52: https://www.bmwfanatics.co.za/thread.../#post-1118687

From some of the dyno results I've seen I don't believe secondary cats being non-existent on Euro models really contributes to additional power. I think a lot of it is tuning and the 3-stage manifold. I believe the N52 X3 in the US had similar if not the same HP numbers as the ones you listed. With that said I have heard of secondary cat removal making the exhaust have a bit more rasp, and giving slightly better throttle response.

I'd be interested in trying it but in my state no shop will even touch cat converters unless they are replacing them. Some shops won't even use high flow cats or customer provided ones.

[The Nightman]

Originally Posted by neilvan

I also knew I wasn't completely insane by his being 2.75" between the res and muffler vs 2.5"

The PE piping is weird too. 2x 55mm to 70mm (resonator delete), down to 65mm piping to the muffler where the inlet is 70mm again. The PE muffler inlet also has gussets to support the coupler there.

Pictured below (PE + AFE midpipes) was my old set up, which I eventually found too loud and obnoxious. Hopefully the 330i exhaust is a good balance, but I still miss the PE's pops and burbles.