Might be time for a new exhaust

[dparm]

I had been wanting an upgrade from the car's underwhelming factory system without breaking the bank for a while now. I'm fortunate enough to have two local members selling M3 sedan exhausts. Both were gracious enough to let me hear the exhausts in person. Now I'm conflicted because I have two very good options to choose from!







This one is a modified stock muffler dubbed the "ACM mod", named after the shop that sort of invented it. Quite an aggressive roar, rather AMG-like, yet no louder than stock muffler under steady-state throttle. It really just sounds like a louder version of the stock exhaust. You won't win any contests in the looks department, but it can't be beat on price. It also offers no weight savings.







The other choice is the BMW M Performance Exhaust, which is sold by dealers. It makes an interesting sound, slightly raspy and exotic, and it reminds me of the older inline-6 M3s. You can hear it at all RPMs and throttle angles, but I wouldn't say it's much louder than stock, just a different sound. The resonated tips are a clean look and you save some weight, but you pay for it dearly -- it costs about 4x as much as the above modified stock muffler.


Part of me wants to just slap the modified stock muffler on and pocket the extra cash, but the M Performance Exhaust is still an intriguing thing. I fear the modded stock muffler is going to wear thin since it's so unrefined and harsh sounding, but the MPE strikes me as rather tinny and raspy sometimes...and even used it feels overpriced.

Both are very popular with owners. I know there's a huge aftermarket out there, but those are even more expensive and I'd prefer to stick with the OEM stuff since I trust the quality and fitment.

Stock system, for reference:

 

[jrustles]

Originally Posted By: dparm

Part of me wants to just slap the modified stock muffler on and pocket the extra cash,


Unless the stocker is excessively massive or a huge restriction, that's what I'd do! Modified stock sounds a bit more mature with the mature financial decision to back it up too!

 

[The_Eric]

My two cents worth is to mod the stock exhaust.

Reasons:

Low dough- you can always spend $$$ later on the other one

Cool sound, which you noted goes away during cruise. That to me is important, because I like to hear the pipes a bit during acceleration, but not cruising from point A to point B on the highway. And I really like the rowdy sound of the modded stock one on the throttle.

The BMW performance exhaust as depicted in the videos almost sounds generic. I've heard that sound in just about every car chase scene.

 

[dparm]

Good point. I can always get the other one later, though I might take a slight hit on the wallet to do that.

The BMW MPE is basically indistinguishable from stock with the windows up. The tone is just barely different. Windows down you can certainly hear it. The modified stock muffler can be heard much more with the windows up (not annoyingly so), and is definitely audible with the windows down.

A few people suggested the Akrapovic "slip-on" (axle-back) since it costs the same as the M Performance Exhaust and sounds more distinct without being obnoxious. I'll probably need to check that out too.

 

[Olas]

JMO, but the best mod for any exhaust is a pipe without any silencers connecting the downpipe to the backbox(uk term for rear silencer - think you call it a muffler?)

weight saving, cheap, throttle position/engine speed dependent sounds almost stock at idle and cruise, but sounds like the devil above a certain rpm&throttle position.

jus sayin..

 

[dparm]

Originally Posted By: Olas
JMO, but the best mod for any exhaust is a pipe without any silencers connecting the downpipe to the backbox(uk term for rear silencer - think you call it a muffler?)

weight saving, cheap, throttle position/engine speed dependent sounds almost stock at idle and cruise, but sounds like the devil above a certain rpm&throttle position.

jus sayin..



The modified stock system I showed above is similar. They basically eliminate the long path it takes through the muffler and it becomes almost straight-through. The stock resonators/middle mufflers are not altered.

 

[Olas]

Lose the centre silencers

manifold/downpipe/nothing/rear silencer

 

[rjundi]

That video of stock is a bit contrived. They are holding camera to the side of car compared to the others where it is directly behind. It does make quite a difference.

I would do the one that is quiet when cruising as it gets old after the first week of ownership going 70mph. My previous experience is Subaru turbo cars.

 

[Mykl]

One of the things about German cars is how much money vendors want for performance exhausts. I can't imagine how much they're asking for M3 parts, because I think what they're asking for GTI stuff is unreasonable and that's certainly less expensive than the BMW.

 

[dparm]

Originally Posted By: Mykl
One of the things about German cars is how much money vendors want for performance exhausts. I can't imagine how much they're asking for M3 parts, because I think what they're asking for GTI stuff is unreasonable and that's certainly less expensive than the BMW.


Agree, and that's why a modified stock muffler is a popular mod. A few hundred bucks and you have a whole new sound.

Those Akrapovic catbacks are insane...$6500+. The M Performance Exhaust was $4000 new from the dealer, but it's made of Inconel which is not cheap.

 

[dailydriver]

Originally Posted By: dparm
The M Performance Exhaust was $4000 new from the dealer, but it's made of Inconel which is not cheap.


Yes, that is an F1/aerospace level material (WAAAYYY above even the top 300 series stainless alloys), almost a 'bargain' for that price, especially from a Bimmer dealer!

 

[hattaresguy]

I like the BMW M exhuast, makes it sound like a BMW. Its not an AMG or a muscle car, I don't think a booming V8 rumble fits the cars character.


But than again I'm old fashion.