stock exhaust mod

[DARK_M3]

Originally Posted by tibra1

$400 all in including purchase of a used OEM to cut up and installation isnt that bad (I kept my original stock exhaust)

Never heard of what you talk about but if you like it then

Oh then that was a pretty good deal!

[EliteM3]

Originally Posted by tibra1

Totally agree..if you are going to replace all 4 pipes or do the bypass mod your are defeating the helmholtz chamber completely and what you end up with essentially is a straight pipe setup..

By replacing just the 2 pipes in the center you are still maintaining the helmholtz through the 2 smaller steel wool wrapped pipes..this is IMO is the best sounding...anything else you get drone and rasp

Turns out that replacing all 4 pipes in the absorption chamber does NOT defeat the helmholtz chamber. Please see the diagram here: http://www.m3post.com/forums/showpos...64&postcount=1

So I stand by my original suggestion of replacing all 4 pipes if you are going to do the exhaust mod. You get the benefit of helmholtz chambers for drone and probably another 10% increase in volume.

Don't get me wrong, the 2 pipe method is awesome, but if you going to replace the pipes...do them all. If anyone doesn't like their 4 pipe replacement, and want to go back to 2...let me know, I will gladly give yours a shot.

[Xuphious]

This is my first post in the forum even though I've been a long time BMW owner and registered here since 2008.


I'd actually like to add input to this thread for people looking to do the OEM mod. Ever since I ordered my M3 late in '08 I planned to keep it bone stock until warranty was up, but that didn't keep me from researching every mod solution possible - especially exhausts. First one to catch my ear was the KKS valvetronic, then the Meisterschaft, then Gintani full race. I really like the throaty rasp and snap that our race-bred V8s can make. There are too many systems out there that ruin that sound.

When the first OEM mods surfaced in 2009, I was pretty sure that's what I wanted to do. Then BMW released the M Performance exhaust and it went straight to the top of my list. Go figure the company that made the car in the first place also had one of the best sounding exhaust upgrades up its sleeves, with full warranty to boot. The problem was the $4300 price tag (or $3800 if you could catch a deal from Tischer BMW.)

Then ACM's version of the mod came out that completely bypasses the absorption chamber. See this thread: http://www.m3post.com/forums/showthread.php?t=647138. Right here I knew this is what I was going to do. From what I can find, this seems to be the exact difference between a stock M3 muffler and the M Performance unit. http://www.m3post.com/forums/showthread.php?t=595586 Post #13 is key. Well, other than $4000 and the Inconel alloy. This version of the OEM mod seems easier than center chamber work, plus it uses the existing elbow pieces that come out to create the S curves that connect Helmholtz chambers to tips.


I just had mine done yesterday, and if I ever had to do it again I would do it the same way in a heartbeat. It sounds 99% stock at idle and 95% stock under light throttle / cruise conditions. But under load and high rpm spirited driving, it's 100% pure, raw awesomeness. I've heard other people say this - and I wholeheartedly agree - the M3 should have been built this way from the beginning.

Plus it looks totally stock (didn't want to change my tips either.) MA can be tough on modded cars, so it's always better to do things that allow you not to attract police attention.


I have to give mad props to Dave and the guys at Bay State Muffler in Peabody, MA. They had never heard of or tried this before, and only ever saw one other E9x M3 come in for standard work. After about 1/2 an hour of discussion over the "instructions" I brought with me (I printed the pics from the ACM style mod,) maybe 2.5 hours of work, and $325, I want to do nothing but drive around all day long listening to my car. If anyone in the Boston / north shore area is looking for this solution, give Bay State Muffler a call (978.536.9300) because they can definitely help out.

[DopeM3]

Originally Posted by Xuphious

This is my first post in the forum even though I've been a long time BMW owner and registered here since 2008.


I'd actually like to add input to this thread for people looking to do the OEM mod. Ever since I ordered my M3 late in '08 I planned to keep it bone stock until warranty was up, but that didn't keep me from researching every mod solution possible - especially exhausts. First one to catch my ear was the KKS valvetronic, then the Meisterschaft, then Gintani full race. I really like the throaty rasp and snap that our race-bred V8s can make. There are too many systems out there that ruin that sound.

When the first OEM mods surfaced in 2009, I was pretty sure that's what I wanted to do. Then BMW released the M Performance exhaust and it went straight to the top of my list. Go figure the company that made the car in the first place also had one of the best sounding exhaust upgrades up its sleeves, with full warranty to boot. The problem was the $4300 price tag (or $3800 if you could catch a deal from Tischer BMW.)

Then ACM's version of the mod came out that completely bypasses the absorption chamber. See this thread: http://www.m3post.com/forums/showthread.php?t=647138. Right here I knew this is what I was going to do. From what I can find, this seems to be the exact difference between a stock M3 muffler and the M Performance unit. http://www.m3post.com/forums/showthread.php?t=595586 Post #13 is key. Well, other than $4000 and the Inconel alloy. This version of the OEM mod seems easier than center chamber work, plus it uses the existing elbow pieces that come out to create the S curves that connect Helmholtz chambers to tips.


I just had mine done yesterday, and if I ever had to do it again I would do it the same way in a heartbeat. It sounds 99% stock at idle and 95% stock under light throttle / cruise conditions. But under load and high rpm spirited driving, it's 100% pure, raw awesomeness. I've heard other people say this - and I wholeheartedly agree - the M3 should have been built this way from the beginning.

Plus it looks totally stock (didn't want to change my tips either.) MA can be tough on modded cars, so it's always better to do things that allow you not to attract police attention.


I have to give mad props to Dave and the guys at Bay State Muffler in Peabody, MA. They had never heard of or tried this before, and only ever saw one other E9x M3 come in for standard work. After about 1/2 an hour of discussion over the "instructions" I brought with me (I printed the pics from the ACM style mod,) maybe 2.5 hours of work, and $325, I want to do nothing but drive around all day long listening to my car. If anyone in the Boston / north shore area is looking for this solution, give Bay State Muffler a call (978.536.9300) because they can definitely help out.

Hey man, I just seen this post and I can't thank you enough for it. Same as you I was hesitating whether to go and waste 3k on an exhaust but then I started looking for the mod on the OEM one instead.

I've seen about 20 videos on YouTube on them, and they sound amazing. I could only imagine in person. I also live in MA (Lawrence) so Peabody is very convenient for me.

I will give these guys a call in the morning. I wanted to ask you a few question:

How much did you end up paying for everything?

Wish I could really hear it in person.

But again, thanks again for the valuable information. Very appreciated!

You're the man!

[gatorfast]

^you wont be disappointed. Sounds loud and raw from the outside but retains a stock-like level inside. Best of both worlds.

[docsdoc]

Has anyone replaced the cats with X-pipe + resonators and combined that with the OEM mod to achieve a cost-effective solution which produces gains in hp?

[Xuphious]

Originally Posted by jochy2048

Hey man, I just seen this post and I can't thank you enough for it. Same as you I was hesitating whether to go and waste 3k on an exhaust but then I started looking for the mod on the OEM one instead.

I've seen about 20 videos on YouTube on them, and they sound amazing. I could only imagine in person. I also live in MA (Lawrence) so Peabody is very convenient for me.

I will give these guys a call in the morning. I wanted to ask you a few question:

How much did you end up paying for everything?

Wish I could really hear it in person.

But again, thanks again for the valuable information. Very appreciated!

You're the man!

The whole job was $325. We agreed to the cost after it was done; they simply couldn't estimate/quote before starting.

I'm in Reading, so just a few exits down 93 from you. Maybe find a time/place that we can meet and you can listen to it?

Wonder if I've ever spotted you on the road? Mine is a black E90, stock 18" wheels.

[DopeM3]

Originally Posted by Xuphious

The whole job was $325. We agreed to the cost after it was done; they simply couldn't estimate/quote before starting.

I'm in Reading, so just a few exits down 93 from you. Maybe find a time/place that we can meet and you can listen to it?

Wonder if I've ever spotted you on the road? Mine is a black E90, stock 18" wheels.

I'm bringing it in Monday morning to get the work done. They quoted me same price, #325.

Mine is a White E92 with Premium 19" wheels.

Yeah sure man, we could definitely meet up!

[Xuphious]

^ PM'd.

[Zaw]

Originally Posted by DARK_M3

Yikes!

Best $0 I ever spent... I did it myself and didn't even have to remove the exhaust from the car.

The deep V8 sound is glorious with all that fiberglass or steel "stuffing" out.

So you did the mod without filling it back with the stuffing? Is there any different in sound or vibration without the stuffing?

Edit: Or did you just take the fiberglass wool out, leaving the pipes alone?

[DARK_M3]

Originally Posted by Zaw

Edit: Or did you just take the fiberglass wool out, leaving the pipes alone?

Yes

[Zaw]

Originally Posted by DARK_M3

Yes

Have you had a chance to compare your mod with other mods? How does the sound compare?

[DARK_M3]

Originally Posted by Zaw

Have you had a chance to compare your mod with other mods? How does the sound compare?

No and IDK. I love the sound though and others have said the same.

[meko]

Anyone know if the 2.5 diameter pipe is an inside or outside diameter when measured. Want to get the right size. I think it's inside but not sure