M3 exhaust modification

[Eugene-TAIWAN]

sound like 1 crazy project.

[Periokid]

Originally Posted by Subw00er

Cool, I am inspirational!



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.

I could also play with the amount of pipe I cover. Perhaps covering half the perforations and restuff the chambers. I saved all the material. I guess I could tune it that way.

Regarding the wrap, I thought about that too. I was thinking of using a muffler repair tape first and then wrapping it on top.

I can test the system before I seal it.

How many times do you think the doors I made can be bent back and forth without breaking?

[Periokid]

New pic. This has un-cured exhaust tape. Plastic tie straps are, of course, temporary.

[Subw00er]

Originally Posted by Periokid

How many times do you think the doors I made can be bent back and forth without breaking?

I think a lot, its strong metal, but the problem is that when you go to weld it back together it will be deformed and will be hard to keep it smooth. We bent ours as little as possible.

[A-Man]

Originally Posted by Periokid

New pic. This has un-cured exhaust tape. Plastic tie straps are, of course, temporary.

i saw the pic an was like this guys an idiot... but then i read ur post.... looks awesome.. keep us updated

[Periokid]

Originally Posted by A-Man

i saw the pic an was like this guys an idiot... but then i read ur post.... looks awesome.. keep us updated

Yeah, I made sure to add that bit of information so I wouldn't look too stupid.

[mastek]

Originally Posted by Subw00er

I think a lot, its strong metal, but the problem is that when you go to weld it back together it will be deformed and will be hard to keep it smooth. We bent ours as little as possible.

Wouldnt it be better to make a clean cut - instead of a bend - and then weld it shut after the mod??

[Periokid]

Originally Posted by mastek

Wouldnt it be better to make a clean cut - instead of a bend - and then weld it shut after the mod??

Well it is one whole area that will not have to be welded. I don't expect much trouble from bending the "door" back closed.

[SOCAL]

Very cool. Can't wait to hear it!

[Periokid]

I got some time for the other side but I ran out of tape. Damn it!

[Space Ghost]

Damn You work fast! Guess I know what you did when you got back. Good luck.

[J08M3]

I'm definitely curious to hear this when you're done... Where on LI?

[Periokid]

Originally Posted by Space Ghost

Damn You work fast! Guess I know what you did when you got back. Good luck.

As soon as I got home I went shopping for supplies and the angle grinder to cut open the muffler. I told myself I would not commit until I had a unit in hand!

Originally Posted by J08M3

I'm definitely curious to hear this when you're done... Where on LI?

I am North Shore past Port Jefferson. I am happy to have you come and hear it.

[smokinjoe64]

...man Periokid, I love the creativity and am eager to learn the results!!!

[JohnnyRoaster]

Nice work! Keep us posted on the results.

[hamad]

cant wait to hair the sound

[zuggerat89]

Originally Posted by Periokid

As soon as I got home I went shopping for supplies and the angle grinder to cut open the muffler. I told myself I would not commit until I had a unit in hand!



I am North Shore past Port Jefferson. I am happy to have you come and hear it.

I wanna come too, I'm in fdale.

[05SCM33]

Here Kitty, Kitty . . . .

[J08M3]

Originally Posted by Periokid

I am North Shore past Port Jefferson. I am happy to have you come and hear it.

Sounds good, I'm out on the South Fork

[B.Hallowell]

I might use you as a giunea pig haha. My dad lives out in Montauk so I can easily make a trip the day we all decide to hear this. If it's an amazing cheap option for more sound I'm game! The stock exhaust is quite impressive as it is. However more sound has never hurt anybody.

[Periokid]

Time for an update.

I finished wrapping the pipes and I bolted it up.

It is ridiculously loud. It sounds amazing.. There may be a volume issue...too loud, perhaps. Now keep in mind, the doors I made have not been sealed. This was just a trial run.

I made a video of cold startup and warm engine. It is raining today so no driving, sorry.

[Subw00er]

Where is the video?

It should be a bit quieter after you button it up fully. When my valves are opened up a smidge, like your access doors are, its definitely noticeable, so you dont need much of a leak for noticeably increased noise. The question is.. will it drone! It would seem to me that the header tape will still allow sound waves to permeate and you've created quite a cavity there. If I were you, I'd seal that area up better and drive around before you weld it back. You may want to cover the tubes with something more rigid and sound reflecting than the header wrap.

If you guys can come north a bit, maybe I may meet up too..maybe get out of the city and work it into a nice fall drive! Its too far to go to LI for a quick meet for me.