OEM Exhaust Mod

[L4ces]

Originally Posted by ///M Power-Belgium

Exactly ..
I could hear from the first seconds (even at start up) the difference in sound in cabin , not only because it was louder but I noticed also the great sound quality and honestly I was really surprised and happy what I heard after a whole day of work with the mod.

Yeah...Outside it's completely different as well , but hard to tell in cabin how it actually sounds outside, that's why I let someone drive with my car while I was along the road (road without other cars) and so I heard some pulls under load and DCT downshifts from my car , and I was like ....Holy shit , this sounds just perfect !

Damn right, too bad we can't hear it in the cabin like that.

[///M Power-Belgium]

Originally Posted by M3ANMACHINE

Interesting, I felt like the ACM method was the most exotic I have heard on the e9x M3 when I had it. Here's an example of my friends car with the ACM method:

However it sounds identical to this video of the 4 pipe method.. hmm..

Now i'm starting to wonder if he was mistaken and actually had the 4 pipe method instead of the ACM method.. I'll have to double check somehow!

Thanks for sharing of the videos
Again ...You need the mod. that you prefer in sound and that is personal taste , it's like some people love the color blue...others love red , ect..
So actually you can put your personal dicision and taste in your mod.

Here they are along each other..
Video #1 shows in order ...

1- Oem stock
2- The 2 big perforated
3- The straight through (ACM)

Video #2 shows the all 4 (2 big + 2 small) replacement ,and before and after the mod.
Advice: Put a headphone on to listen..

[becausephilchow]

After those videos, I'm pretty sure I'm going to be very happy with the 2 Pipe method.

The 4 pipe might be a bit too loud for my tastes, and not a fan of the risk of drone.

[Changm3]

I recently got my m3 done with the acm method and it sounds awesome, i'm still having my windows down whenever I can. The only time it drones if i'm cruising on highway speeds in fifth gear. ALSO I am a strong believer that videos just can't do enough justice, If you can somehow find someone in HK that has it take a listen, it sounds a lot better in person!

[becausephilchow]

Originally Posted by CHANG_M3

I recently got my m3 done with the acm method and it sounds awesome, i'm still having my windows down whenever I can. The only time it drones if i'm cruising on highway speeds in fifth gear. ALSO I am a strong believer that videos just can't do enough justice, If you can somehow find someone in HK that has it take a listen, it sounds a lot better in person!

Sadly, most people in HK opt for a full exhaust. I would, but, this car is my daily, and I already have a loud as all hell C63 that I can drive around when I want something loud. Which is why I won't do an exhaust on the M3, heh.

[GOFAST M3]

I just got the 2.5 pipe mod done yesterday, and I am really enjoying it. It is significantly deeper than before and it is louder than the videos make it out to be for sure. I would probably have been content with the 2 pipe version to be honest. I don't think it is too loud I really do like it, but I wasn't looking for much and would not want it any louder.

I have not experienced any drone yet, but time has been short and I was only on the highway for a few miles this morning. The way it is though, I will be shocked if it drones.

[blue-mw]

Sorry to revive an old thread but I'm debating doing the OEM vs ACM exhaust mod but had two quick questions.

I know with OEM mod I'll need replacement 6-7" pieces, but not sure of diameter/material needed?

Got a good quote from a local welding shop, but they asked me to provide the replacement pipe pieces. From the looks of it the ACM mod, which I'm leaning towards, can be done with the materials already found in the muffler. Is that the case or would I need to find additional materials?

Thanks for any insight.

[AAliVEE]

Well, i finally manned up and did this mod, as i hate drone and most aftermarket suffer from it this one just made sense.
We use this as a family car and go on long trips with two kids in the rear so drone just _cannot_ be.

This took me about 5 hours, taking my time.
I also broke both of the bolts that connect the back to section to the middle, fortunate i did manage to find replacements in the garage. Otherwise you are looking at 2x15 bucks to buy new clamps/bolts.

I did not cut out any pipes, i did wrap both of the "big" pipes in there.
First with some proper alu-tejp and then self addesive fiberglas on a roll and secured it all with stainless clamps, much like this english dude on m3cutters.

As i did this by myself i did use a jack to lower the muffler down as it is pretty heavy..

I was worried about welding the muffler back up as it was a long time since last welding anything, but with a good MIG and no hurry it was childplay

And the result?
Well jesus christ would have been impressed with this sound!

After cold start it settles and goes almost as quiet as stock, but when rpms climbs towars 3000 and up the orchester just goes on drugs

I am a super-happy-camper-modder today and with ZERO drone but still all this awsome exhaust notes it is just a straight win.

Total cost; almost as little as the drone i did not get

[M3ANMACHINE]

So i've now had both the ACM Mod on my first e90 m3 and just recently installed a 4 Pipe Perforated Mod onto my new e90 m3. Here's the differences I have noticed since I have lived with both for some time now:

ACM Mod:
-loudest of the exhaust mods (approximately 110dB at 75% throttle)
-very slight drone at the normal rpm's
-very exotic tone throughout entire rpm band
-quite noticeable from in-cabin
-completely DD'able

4 Pipe Perf. Mod:
-second loudest of the oem mods (approx. 100dB at 75% throttle)
-exotic tone at light throttle but a more "muscley" v8 tone under WOT
-not a noticeable of a volume increase in-cabin
-zero increase in drone compared to stock OEM muffler
-also completely DD'able

[jv92red]

Originally Posted by M3ANMACHINE

ACM Mod:
-very exotic tone throughout entire rpm band

4 Pipe Perf. Mod:
-exotic tone at light throttle but a more "muscley" v8 tone under WOT

So would you say the ACM mode sounds 'MORE' exotic than the 4 pipe?

Also, which one do you like more that you have had plenty of time with both?

[M3ANMACHINE]

Originally Posted by jv92red

So would you say the ACM mode sounds 'MORE' exotic than the 4 pipe?

Also, which one do you like more that you have had plenty of time with both?

Honestly I prefer the ACM mod. It definitely had a MORE exotic tone.

[thkfast]

The more I read about these mods, the more I'm leaning towards a non-cutting/welding solution. I never even thought about cutting the 2 1/2" sections in half, covering the perforated sections and hose clamping them. I might try that method or the muffler tape and exhaust wrap way. I'm very excited to increase the sound - stock it's way too tame, especially next to my friends C63 AMG.

[Stunnerable]

Anyone have an example of the 2.0 but with a primary cat delete? Looking for that reserved at low rpm operation to absolute psychopathic maniac at high rpm. Please advise.

[Sammy82]

I have also an exhaust mod since last month.
My MPE is fully cracked and the drone was horrible
My mod is called "soft Plus". So its right between soft and medium.
I also have primary cat delete

Absolutley no drone
Sound isn`t so metallic at higher revs as the MPE.
When driving at lower rpm, its like OEM.
But very powerfull when fully acceleration

For me, this is the perfect sound

Also I have 80mm stainless steel tips with an engraved M logo

[brplatz]

Originally Posted by Sammy82

I have also an exhaust mod since last month.
My MPE is fully cracked and the drone was horrible
My mod is called "soft Plus". So its right between soft and medium.
I also have primary cat delete

Absolutley no drone
Sound isn`t so metallic at higher revs as the MPE.
When driving at lower rpm, its like OEM.
But very powerfull when fully acceleration

For me, this is the perfect sound

Also I have 80mm stainless steel tips with an engraved M logo

Well lets see a video!

2 pipe, 4 pipe?

[Sammy82]

Should sound like this:

The two large pipes wrapped plus 1/2 of each of the other two

[hero149]

anyone have any experience with a megan supremo exhaust? is it louder and throatier than a 2 pipe oem exhaust mod? debating between the 2...

[zstreet86]

What is the diameter of the larger perf pipes? 3 inch?

[wfdeacon88]

Originally Posted by zstreet86

What is the diameter of the larger perf pipes? 3 inch?

yes I believe so.

[SoCalRPM]

Originally Posted by serranot

I got some of the black chrome OEM ones from an e92 and had a machine shop cut the rolled ends off. They are now e90 length and only have the single wall so they look as if the are larger diameter.

Digging up an old post here — happen to have any photos of the result?

[serranot]

Originally Posted by SoCalRPM

Digging up an old post here — happen to have any photos of the result?

Sorry about the dirt.

[SoCalRPM]

Originally Posted by serranot

Sorry about the dirt.

Dirty indeed! But through the grime it looks nice!