[The Nightman]

The 330i exhaust is in. Big thanks to neilvan for bringing this to my attention. Simply cut the 328i exhaust out after the secondary cats and reinstall the 330i exhaust with two 55mm Torca couplers (Walker 36535). If you can fit it under the car, a reciprocating saw with a 24 TPI metal blade makes quick work of the piping. The Torca couplers are made in Germany but are "assembled" in a Mexican bag - customs officers hate this one trick!

Both exhausts are made in Germany by Eberspacher but have different part numbers:

              328i    330i
Resonator  7544506 7544507
Muffler    7544508 7544509

The piping between the resonator and muffler are different in both size and routing. The 330i piping is 70mm but the 328i 65mm piping appears to be more efficient with smoother bends and less kinks. I think it would be difficult to adapt the 330i muffler onto 328i piping, unless you have an N51 with 70mm piping. The hanger bracket after the resonator is different but mounts up the same. Both mufflers have a 32hz dampener, but the 330i muffler has chrome tips instead of brushed metal.

For reference, I currently have the eurobox with a 3" ram air duct and paper filter, 330i intake manifold, and catless "Mapleridge" headers. I previously had stock headers with AFE midpipes (secondary cat delete) and the PE, which I found to be too loud and obnoxious.

The 330i exhaust tone is deeper with just enough volume to sound like a factory sports exhaust. The differences seem most noticeable at low to mid RPMs. However, with the valve always open, it's quite loud and deep on cold starts and when idling. I haven't driven enough to comment on droning. I want to say that the car does seem to accelerate much quicker, but I will attribute that to the colder temperatures rather than the exhaust.

I took a video but it doesn't come close to capturing the actual sound. In real life, the exhaust is deeper and louder:

[CTinline-six]

Originally Posted by Guy Fieri

The 330i exhaust is in. Simply cut the 328i exhaust out after the secondary cats and reinstall the 330i exhaust with two 55mm Torca couplers (Walker 36535). If you can fit it under the car, a reciprocating saw with a 24 TPI metal blade makes quick work of the piping. The Torca couplers are made in Germany but are "assembled" in a Mexican bag - customs officers hate this one trick!

Both exhausts are made in Germany by Eberspacher but have different part numbers:

              328i    330i
Resonator  7544506 7544507
Muffler    7544508 7544509

The piping between the resonator and muffler are different in both size and routing. The 330i piping is 70mm but the 328i 65mm piping appears to be more efficient with smoother bends and less kinks. I think it would be difficult to adapt the 330i muffler onto 328i piping, unless you have an N51 with 70mm piping. The hanger bracket after the resonator is different but mounts up the same. Both mufflers have a 32hz dampener, but the 330i muffler has chrome tips instead of brushed metal.

For reference, I currently have the eurobox with a 3" ram air duct and paper filter, 330i intake manifold, and catless "Mapleridge" headers. I previously had stock headers with AFE midpipes (secondary cat delete) and the PE, which I found to be too loud and obnoxious.

The 330i exhaust tone is deeper with just enough volume to sound like a factory sports exhaust. The differences seem most noticeable at low to mid RPMs. However, with the valve always open, it's quite loud and deep on cold starts and when idling. I haven't driven enough to comment on droning. I want to say that the car does seem to accelerate much quicker, but I will attribute that to the colder temperatures rather than the exhaust.

I took a video but it doesn't come close to capturing the actual sound. In real life, the exhaust is deeper and louder:

Sounds good! Maybe I need headers on mine now.

[The Nightman]

Wanted to report back after a bit more seat time. The 330i exhaust is nearly the perfect "OE sport" exhaust. I was pleasantly surprised to hear some backfiring on overruns and downshifts, although it is very subtle and deep and nothing like the wild pops and crackles of the PE.

The only downside is there is some mild droning around 2000rpm, and cold starts are also quite loud. This is probably because the exhaust valve is always open.

My only other exhaust modification are "Mapleridge" catless headers.

[cbyrne]

Sorry to revive a somewhat old thread, but I wanted to thank Guy Fieri and others that have posted in this useful thread

I had a muffler from an E90 330xi welded onto my E92 328i today.

The shop stated that the connection from the S-pipe that meets the back of the resonator is identical between the two exhausts

Take that with a grain of salt - who knows which models, years, and exhaust variants are compatible with one another. But I was told that no adapting pipe was needed.

For the tips, the 330 tailpipe had some rust and staining that didn't look super great so the shop slipped on the 328i tips to cover it up and it's a good fit (not perfect but more than acceptable.)

The sound is perfect - I would estimate about a 10-15% increase in volume, maybe slightly more at WOT in higher gears. No real drone to report, just a nice sporty bass undertone.

This was absolutely worth the money and effort - the aftermarket options for N52 are much too loud for my taste - keeping the OE resonator in place and just opting for the less restrictive 330 muffler design is perfect for my taste and can be done at a reasonable cost. Follow me on IG @n52_e92 if you're interested where I'm hoping to put up some sound clips soon

Cheers

[triax37]

Originally Posted by neilvan

I had a 55mm clamp and 65mm clamp on hand; used the 55mm for pre-resonator and it worked but the 65mm rear clamp would not work on the 330i piping just before the muffler. I originally had just a muffler to swap out but once realizing that the post resonator pipe was a different diameter(visibly too) I had to sell and get a resonator back system.

What difference, if any, should I expect to the sound and driving performance if I just installed the 330 muffler to my 328 exhaust without the post-resonator pipe? I’m hoping there is an adapter or clamp of some type that would make the exhaust function. It’s tough to find those 330 parts these days, but I have found a 330 muffler. Thanks!

[neilvan]

Originally Posted by triax37

What difference, if any, should I expect to the sound and driving performance if I just installed the 330 muffler to my 328 exhaust without the post-resonator pipe? I’m hoping there is an adapter or clamp of some type that would make the exhaust function. It’s tough to find those 330 parts these days, but I have found a 330 muffler. Thanks!

Sound would be the same; only difference is some have a 65mm post res diameter and some have 70mm diameter for the 330i. I doubt any human ear would notice a difference as the resonator internals are the same for both.

There is no adapter; you will need custom if you got the larger one (the piping is a slightly different shape too so I think a welded adapter is still best)