M3 exhaust modification

[sehrgut]

Originally Posted by Periokid

When I did a trial run, I had wrapped all the holes and then did a test. The first video in this thread is the first attempt. When I started the car, I was like OMG, I thought the house would come down!

The video is post #45: http://www.m3post.com/forums/showpos...7&postcount=45

and

#46 http://www.m3post.com/forums/showpos...2&postcount=46

It was too loud and I felt I needed to open up a few holes and put the sound absorbing material back in to absorb the sound that would come out of those reopened holes. The backfire in those early videos has not occurred again.

Yes I saw those videos, awesome man. I'm going to play around with this as well i think. Question, do you know what caused the backfire? I was thinking doing like you did but i will remove the sound absorbing material and thats it. You think it will be too loud? I will try and see, do a little testrun like you did before actually weld it together.

Likewise, im more after the sound then the hp gain (ofcourse it would be nice with some gain and im sure this exhaust mod will get you some gain hp). Have you had your car on a dyno before and after to see if there were any hp gains?

Ones again, good job, im impressed over the nice results, cool.

[Periokid]

Originally Posted by sehrgut

Yes I saw those videos, awesome man. I'm going to play around with this as well i think. Question, do you know what caused the backfire? I was thinking doing like you did but i will remove the sound absorbing material and thats it. You think it will be too loud? I will try and see, do a little testrun like you did before actually weld it together.

Likewise, im more after the sound then the hp gain (ofcourse it would be nice with some gain and im sure this exhaust mod will get you some gain hp). Have you had your car on a dyno before and after to see if there were any hp gains?

Ones again, good job, im impressed over the nice results, cool.

Without the sound absorbing material I was worried about drone or booming. But who knows, give it a shot!

I have no idea on gains. I don't expect anything. I have not run the car on a dyno.

[Space Ghost]

Sounds awsome. I think the used exhaust market price just increased. Enjoy.

[s99ane]

Wow love this mod. Its just what Im after.
Out of curiosity why seal off the large pipe instead of the small one?

If I were to get a decent spanner jockey to do this for me..... how long do you recon it would take from start to finish? Couple of hours???

PS respect to you for having a go and love the plate

[Periokid]

Originally Posted by s99ane

Wow love this mod. Its just what Im after.
Out of curiosity why seal off the large pipe instead of the small one?

If I were to get a decent spanner jockey to do this for me..... how long do you recon it would take from start to finish? Couple of hours???

PS respect to you for having a go and love the plate

Not sure what you mean about large pipe. Do you mean the one with more holes? If so, I did cover that one. I only left the pipes with the fewer holes open.

Thanks for the compliments.

[PrePharm]

Awesome work!!!!!! I am thinking about doing this, during winter break, if I don't purchase an Eisenmann.

[s99ane]

Originally Posted by Periokid

Not sure what you mean about large pipe. Do you mean the one with more holes? If so, I did cover that one. I only left the pipes with the fewer holes open.

Thanks for the compliments.

What Im getting at is what difference would it make to cover the other pipe... with fewer holes? Sorry for my ignorance.

[Periokid]

Originally Posted by s99ane

What Im getting at is what difference would it make to cover the other pipe... with fewer holes? Sorry for my ignorance.

http://www.m3post.com/forums/showpos...&postcount=132

[Periokid]

Well I had the car out for the first highway run. I would say the exhaust is loudest at 3000 rpm. Is has quite a sound. It is pretty loud but not annoying which was my greatest fear. You can certainly notice the increased volume. I am loving it!

[Subw00er]

PK, I've of course been following along. Great job! It has a similar sound to mine when I have my valves open about 1/3-1/2. Your's doesn't seem to have the snap that mine has at WOT or high rev blipping, but otherwise its quite similar in tone, which I guess when considering the similarity of our two mods, makes sense. I wonder if in person your's has the European wallow that is so hard to describe or pickup on mic - its my favorite part of my exhaust now.

I wonder, for future modders, why not just open one side and mod what you can from there - would take 1/2 the work that PK put in. OK, who's gunna sign up to do that?

For those that are new to my setup, here is my vid (I use two remote controllable valves to essentially dump the exhaust before the muffler sections of the exhaust which allows me to control the level from very loud to totally stock sounding):
[u2b]<object width="853" height="505"><param name="movie" value="http://www.youtube-nocookie.com/v/MGvN-2BQk1o&hl=en&fs=1&hd=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube-nocookie.com/v/MGvN-2BQk1o&hl=en&fs=1&hd=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="853" height="505"></embed></object>[/u2b]

If would be great to meet up at some point to hear in person. Again, great job and thanks for keeping us in the loop.

[Periokid]

Just kidding

[s99ane]

Interesting point made by Subwoofer... what if only one side were opened up? Could open both pipes on one side only or one pipe only...

hmmmmm

[sehrgut]

Originally Posted by Subw00er

PK, I've of course been following along. Great job! It has a similar sound to mine when I have my valves open about 1/3-1/2. Your's doesn't seem to have the snap that mine has at WOT or high rev blipping, but otherwise its quite similar in tone, which I guess when considering the similarity of our two mods, makes sense. I wonder if in person your's has the European wallow that is so hard to describe or pickup on mic - its my favorite part of my exhaust now.

I wonder, for future modders, why not just open one side and mod what you can from there - would take 1/2 the work that PK put in. OK, who's gunna sign up to do that?

For those that are new to my setup, here is my vid (I use two remote controllable valves to essentially dump the exhaust before the muffler sections of the exhaust which allows me to control the level from very loud to totally stock sounding):
[u2b]<object width="853" height="505"><param name="movie" value="http://www.youtube-nocookie.com/v/MGvN-2BQk1o&hl=en&fs=1&hd=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube-nocookie.com/v/MGvN-2BQk1o&hl=en&fs=1&hd=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="853" height="505"></embed></object>[/u2b]

If would be great to meet up at some point to hear in person. Again, great job and thanks for keeping us in the loop.

Ive followed your thread, awesome with e-cutouts. But about what you said just open one side and mod what you can from there, what do you mean? Sorry for me asking, just curious because Ive been thinking about this.

[Poppin Fresh]

Originally Posted by s99ane

Interesting point made by Subwoofer... what if only one side were opened up? Could open both pipes on one side only or one pipe only...

hmmmmm

Or you could tape/cover up all except the one set of smaller holes and put back all the insulating fibers.

[Periokid]

BTW, if anyone wants hear it in person, let me know.

[s99ane]

Originally Posted by Periokid

BTW, if anyone wants hear it in person, let me know.

I sure would i will pm you te adress where to post the airline tickets to so I can come check out your car

[joaquin03]

great job! kudos to your ingenuity!

[spyderco10]

good job, and you did it all at a fraction of the cost of buying aftermarket.

[s99ane]

Ok let me get this right.
The more holes covered the louder the system is and more hp also?

[Periokid]

Originally Posted by s99ane

Ok let me get this right.
The more holes covered the louder the system is and more hp also?

Well I don't know about hp, but the more holes covered the louder it will be. I had all the holes covered in my first test and it seemed like too much for me.

[Bart@AUTOcouture]

awesome job dude!

[Poppin Fresh]

This is definitely one good option to choose for me since I can't make up my mind on what system to get. So, let's say I leave all but one set of hole (large or small amount). Would it be a step down on the tone and volume your exhaust? Or would it give the opposite effect? Thank you in advance.