M3 exhaust modification

Periokid · 11-08-2009, 08:02 PM

Subw00fer has inspired me.

His phenomenal exhaust system has motivated me to try a mod of my own.

My idea was post #197 on this thread located here: http://www.m3post.com/forums/showthread.php?t=253661

Basically I wanted the sound without the actuators. Not nearly as cool as the Bates Prototype Valvetronic Exhaust, but something I want to try.

The idea is to open the absorption chambers, take out the absorption material and seal the perforated pipes. I am not sure what to expect but I am hoping to get some sound similar to the Bates Prototype.

My first step was to obtain a used unit. Thanks to Space Ghost, that step was completed today with a deal in a mall parking lot which quickly brought over security thinking we were doing a drug deal!

Next I cut open the chambers and pulled out a mile of material. It was almost comical. It just kept coming out and was endless. Then I removed the steel wool like material from each side covering a small section of two pipes. Now I have clean chambers and exposed perforated piping. My plan is to wrap the pipes with header wrap and seal the chambers.

Here are some pics:

Periokid · 11-08-2009, 08:06 PM

More Pics:

ahtim · 11-08-2009, 08:08 PM

this is some serious good shit!!!!

has anyone ever though of doing a full straight pipe, from the header to the rear tip running a straight titian pipe, without any muffler, it must be sick!!!!!!

Periokid · 11-08-2009, 08:12 PM

Quote:

Originally Posted by ahtim

this is some serious good shit!!!!

has anyone ever though of doing a full straight pipe, from the header to the rear tip running a straight titian pipe, without any muffler, it must be sick!!!!!!

I don't know about doing the whole straight pipe thing but the idea here is to still have the use of the Hemholtz Chambers to combat drone.

See the diagram: http://www.m3post.com/forums/showpos...4&postcount=19

Krozi · 11-08-2009, 08:15 PM

There is a dead animal in your exhaust! :P

Good job!

Periokid · 11-08-2009, 08:17 PM

Quote:

Originally Posted by Krozi

There is a dead animal in your exhaust! :P

Good job!

Yeah, my wife was like, "WTF is that!"

elp_jc · 11-08-2009, 08:30 PM

Great project. I'd just close it like that man; might give you a deeper sound without all that material, no? If you don't like it, then wrap the perforated sections. Just an idea. Please keep us posted

.

J08M3 · 11-08-2009, 08:41 PM

Cool idea... although I imagine it will probably drone quite a bit. All that "eliminated" drone sound is absorbed by the material you just removed.

Krozi · 11-08-2009, 08:52 PM

Quote:

Originally Posted by J08M3

Cool idea... although I imagine it will probably drone quite a bit. All that "eliminated" drone sound is absorbed by the material you just removed.

+1

Periokid · 11-08-2009, 09:13 PM

Quote:

Originally Posted by J08M3

Cool idea... although I imagine it will probably drone quite a bit. All that "eliminated" drone sound is absorbed by the material you just removed.

According to Subw00fer, the drone is addressed by the Hemholtz chambers. His bypass system basically sends the exhaust right out, just past the Hemholtz chambers and he has no drone. We shall see.

J08M3 · 11-08-2009, 09:14 PM

Quote:

Originally Posted by Periokid

According to Subw00fer, the drone is addressed by the Hemholtz chambers. His bypass system basically sends the exhaust right out, just past the Hemholtz chambers and he has no drone. We shall see.

Yea, but all the absorbing material just got taken out of the chamber. Subw00fer left his in there, that's why his works.

Periokid · 11-08-2009, 09:27 PM

Quote:

Originally Posted by J08M3

Yea, but all the absorbing material just got taken out of the chamber. Subw00fer left his in there, that's why his works.

The material I removed was from the absorption chambers, not the Hemholtz chambers. The material is removed so I can wrap the perforated pipes. I can still put the material back in if I had to but it shouldn't matter since the Helholtz chambers are still sealed.

rsmamg · 11-08-2009, 09:30 PM

Quote:

Originally Posted by Krozi

There is a dead animal in your exhaust! :P

Good job!

Poppin Fresh · 11-08-2009, 09:36 PM

Jesus! Is that a poodle?!!

mastek · 11-08-2009, 09:39 PM

Quote:

Originally Posted by Periokid

The material I removed was from the absorption chambers, not the Hemholtz chambers. The material is removed so I can wrap the perforated pipes. I can still put the material back in if I had to but it shouldn't matter since the Helholtz chambers are still sealed.

interesting .... keep us posted.
how long b4 video of unit on car?

elp_jc · 11-08-2009, 10:24 PM

Quote:

Originally Posted by J08M3

Cool idea... although I imagine it will probably drone quite a bit. All that "eliminated" drone sound is absorbed by the material you just removed.

As Periokid said, the drone (Helmholtz) chambers are at the ends; that's why I suggested just buttoning it up. The removed material is just to quiet the exhaust. I say it should sound great just like that, but it's up to you to try it or not. Take care.

Poppin Fresh · 11-08-2009, 10:32 PM

Please post vids of the results...hope it all goes well.

MrHarris · 11-08-2009, 11:26 PM

Pretty cool. Does the stock exhaust have a lot of near 90 degree bends inside it?

H Bomb · 11-08-2009, 11:55 PM

i know of one on an M6. it is sick nasty. i was hoping they would do it for the M3 but not yet just straight with resonators. with that V10 it sounded insane in the upper rpm's

Quote:

Originally Posted by ahtim

this is some serious good shit!!!!

has anyone ever though of doing a full straight pipe, from the header to the rear tip running a straight titian pipe, without any muffler, it must be sick!!!!!!

H Bomb · 11-08-2009, 11:57 PM

any sound clips??

Subw00er · 11-09-2009, 12:18 AM

Cool, I am inspirational!

Quote:

Originally Posted by J08M3

Yea, but all the absorbing material just got taken out of the chamber. Subw00fer left his in there, that's why his works.

I suppose it is possible that the muffled sections do kill some drone as well, even when my valves are open, but I guess we wont know till he buttons it up and lets us know!

Exhaust gasses, and thus sound waves, do flow through the stock pipes when my valves are open. Because I "T"ed off of the oem pipe, it would seem that the path the sound and flow would want to take would be straight through. It will be interesting to see how this turns out.

Header wrap seems to be a good idea btw, but is that stuff air tight? Also, I'm not sure its designed to resist an exhaust "leak" like you'll be imitating. I was thinking that a layer of some kind of thick metal tape would be good - maybe even under the wrap. I think they make high temp stuff - try mcmastercarr.com.

montreal red · 11-09-2009, 12:47 AM

this should be a great project !

11-08-2009, 08:02 PM	#1
Periokid Second Lieutenant Drives: 2009 e93 M3 (gone and missed) Join Date: Apr 2009 Location: LI, NY Posts: 246 iTrader: (0)	M3 exhaust modification Subw00fer has inspired me. His phenomenal exhaust system has motivated me to try a mod of my own. My idea was post #197 on this thread located here: http://www.m3post.com/forums/showthread.php?t=253661 Basically I wanted the sound without the actuators. Not nearly as cool as the Bates Prototype Valvetronic Exhaust, but something I want to try. The idea is to open the absorption chambers, take out the absorption material and seal the perforated pipes. I am not sure what to expect but I am hoping to get some sound similar to the Bates Prototype. My first step was to obtain a used unit. Thanks to Space Ghost, that step was completed today with a deal in a mall parking lot which quickly brought over security thinking we were doing a drug deal! Next I cut open the chambers and pulled out a mile of material. It was almost comical. It just kept coming out and was endless. Then I removed the steel wool like material from each side covering a small section of two pipes. Now I have clean chambers and exposed perforated piping. My plan is to wrap the pipes with header wrap and seal the chambers. Here are some pics:
	Tweet

11-08-2009, 08:41 PM	#8
J08M3 Major General Drives: 2011 M3 COUPE Join Date: May 2008 Location: NEW YORK Posts: 6,015 iTrader: (8)	Cool idea... although I imagine it will probably drone quite a bit. All that "eliminated" drone sound is absorbed by the material you just removed. __________________

11-08-2009, 09:36 PM	#14
Poppin Fresh Colonel Drives: With a sunroof and front plate Join Date: May 2009 Location: Bergen County NJ Posts: 2,044 iTrader: (0)	Jesus! Is that a poodle?!! __________________

11-08-2009, 10:32 PM	#17
Poppin Fresh Colonel Drives: With a sunroof and front plate Join Date: May 2009 Location: Bergen County NJ Posts: 2,044 iTrader: (0)	Please post vids of the results...hope it all goes well. __________________

11-08-2009, 11:26 PM	#18
MrHarris yodog Drives: '86 Corolla Join Date: Jun 2007 Location: Diamond Bar, Ca Posts: 5,032 iTrader: (5) Garage List 2009 BMW [5.00]	Pretty cool. Does the stock exhaust have a lot of near 90 degree bends inside it? __________________ 2009 E92 M3 \| Alpine White \| Black Extended \| Advan RS \| Turner Test Pipes \| Dinan Axle-Back \| OETuning \| Eibach Springs \| UUC SSK \| VRS Front Lip \| VRS Type I Diffuser \| Matte Black \| RPi Scoops \| MS Filter \| Yokohama AD08 \| F1 Pinnacle Special Thanks: Gintani \| OETuning \| eAs

11-08-2009, 08:06 PM	#2
Periokid Second Lieutenant Drives: 2009 e93 M3 (gone and missed) Join Date: Apr 2009 Location: LI, NY Posts: 246 iTrader: (0)	More Pics:

11-08-2009, 08:08 PM	#3
ahtim Akrapovic HK Drives: mostly NA, sometimes turbo Join Date: Oct 2008 Location: Hong Kong, Posts: 211 iTrader: (0)	this is some serious good shit!!!! has anyone ever though of doing a full straight pipe, from the header to the rear tip running a straight titian pipe, without any muffler, it must be sick!!!!!!

11-08-2009, 08:15 PM	#5
Krozi Deutsche Jung aus Kölle Drives: 2008 E92 ///M3 Alpine White Join Date: Oct 2009 Location: SoFla - Bonita Springs Posts: 2,699 iTrader: (20)	There is a dead animal in your exhaust! :P Good job!

11-08-2009, 08:30 PM	#7
elp_jc Brigadier General Drives: . Join Date: May 2008 Location: . Posts: 4,912 iTrader: (0)	Great project. I'd just close it like that man; might give you a deeper sound without all that material, no? If you don't like it, then wrap the perforated sections. Just an idea. Please keep us posted .

11-08-2009, 11:57 PM	#20
H Bomb Lieutenant Colonel Drives: 08 M3 Join Date: Jul 2007 Location: FL to NY Posts: 1,686 iTrader: (4)	any sound clips?? __________________ Street- 08 E92 M3- Sparkling Graphite/ Fox Red/6sp Track- 10 CRF 250-PR2 Race Motor/Ohlins TTX Susp Hauler- 06 Ford Skyjacker F250 4WD

11-09-2009, 12:47 AM	#22
montreal red chris Drives: Green Frog Join Date: Jun 2007 Location: Montreal Posts: 12,085 iTrader: (31)	this should be a great project ! __________________ 997.1 GT3RS 2009 WRX STI e92 M3 (gone)

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