M3 exhaust modification

[Grail05]

Originally Posted by birgppa

how much are you guys paying for a used oem muffler in the states?

sold mine for $150

[JCtx]

Hey gang, did anybody tried just 2 clamps on each side? That'd cover most of the long perforations, leaving a bit of perforations open for absorption, as well as the short perforations. Might sound just perfect. I like the idea of being able to put back to stock if needed. I think I'm going to do this. Seems to be what I want. Sounds as good as the best exhausts out there, with OEM fit (and heat shields), and should cost less than a 10th of the next best thing, which is the BMW performance one. Have a good one folks.

[Poppin Fresh]

Most of the modified exhaust have sounded a little louder than what was expected. I'm wondering if shutting the smaller perforations and leaving the larger ones would result in a desired sound.

[Tommiexboi]

this is sick!!

[xsboost]

I just want to throw my 2 cents in, I did this mod to my exhaust a week ago, we welded 2 sleeves over the large sections of the preforated pipes. Once we welded the cut pieces back on, I was a little disappointed in the loudness of the exhaust, so we cut it open and covered the smaller preforated sections too, this only added about 15-20% to the loudness level.

I think the OP saw a much larger difference than me during his testing because his muffler cuts weren't full sealed where as mine were.

I'm happy with the sound level but I had the exact same mod done to my Corvette and that was twice as loud as the M3. I think the helmhotz chambers quiten the exhaust level a lot.

Moral of the store, for the hardcore guys cover everything.

[Subw00er]

FYI the helmhotz chambers dont quieten the exhaust much at all. Look for my posting about the Bates valvetronic exhaust (sig). My pipes are open post helmholtz and they are very loud when my cutouts are open.

BTW my JEGS cutouts have been flawless since installed.

[pablo e92]

Originally Posted by paul walker

Here's my plan on what I'm going to do, it's a lot more work than what you guys have all been doing but like I said it's similar to what I did on my Cayenne Turbo and this made me a lot of power on that car. I may just weld straight pipes through instead of reusing the perforated pipes, I may even try both just to see the difference in sounds.

THIS!!! Somebody needs to try this. Cut the long perforated pipe out of the center and re-install it straight out the back. I'd leave in all the absorber material and also NOT seal the passage between the left and right sides. Leave that open as is.

[JCtx]

Tried everybody on this crappy city to do the mod for me, and nobody wanted to take the risk. One guy said a TIG welder was 'too hot' for a muffler, and needed to be a MIG welder few people have around here. Found one shop that does, but guy doesn't know what material to use to cover the pipes, and where to get it. Guess will stay stock then . Not economically feasible to buy an angle grinder and a welder, and learn on my stock exhaust . Oh well. Maybe a used Corsa, which looks better (painted black) than a Dinan but still ugly as sin , sounds the same or better, has the same or less drone, and costs about half. At least tried to get this mod done. Take care gang.

[Poppin Fresh]

Just get a Megan exhaust and paint that shit ceramic black. I might just do this.

[kitw]

Originally Posted by Wall$treet

Not sure why so many people want a more bassy v8 growl on an m3

You know, don't be a douche. If everyone wanted the same thing on their cars, life would be really boring. Understand that what you like is not what other's like. Allow for other tastes and allow for people to like what they like. Just because you can't understand it doesn't mean that it isn't valid.

[JCtx]

Originally Posted by Poppin Fresh

Just get a Megan exhaust and paint that shit ceramic black. I might just do this.

Any drone with that? Without anti-resonance chambers, I'm sure it drones more than I'm willing to tolerate . But thanks for the suggestion. And yes, the price is great.

Originally Posted by Wall$treet

Someone before speculated on rasp without the material but where is the evidence this would change raspiness?

It's common sense, since the muffler would basically become a tin can, but somebody already tried it, and even posted a sound clip of it. And yes, it sounded like crap. If you have perforations, you need insulation around them (absorption chamber).

[ryguy84]

Originally Posted by pablo e92

THIS!!! Somebody needs to try this. Cut the long perforated pipe out of the center and re-install it transversely straight out the back. I'd leave in all the absorber material and also NOT seal the passage between the left and right sides. Leave that open as is.

I really hope someone trys this Ill be waiting someone please

[Subw00er]

Originally Posted by ryguy84

I really hope someone trys this Ill be waiting someone please

If I understand what he's suggesting, thats pretty much what I did.. Check my sig for pics.

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[pablo e92]

No, what I meant was to do what Paul Walker proposes in post 264. Avoids all those turns in the center section. Might actually make power.

[Subw00er]

Oh, I see. You'd probably loose torque and gain HP with less back pressure. Thats what I clearly found when I dyno'ed with valves open vs closed.

[pablo e92]

Is there even room to do what Mr. Walker proposes? Also, does anybody know what the inside of the BMW performance muffler looks like?

[ryguy84]

Originally Posted by pablo e92

Is there even room to do what Mr. Walker proposes? Also, does anybody know what the inside of the BMW performance muffler looks like?

I was at a exhaust shop today and the same question was asked about the bmw performance muffler. Someone has to open one up.

[GewoW]

[ryguy84]

Originally Posted by GewoW

so what did you do I like it!

[ChrisK]

That sounds fantastic!!! Yes, what did you do!?

[e92Mjunky]

not very deep, kind of high pitched and tin can sounding..but better than stock none the less...still weighs the same I assume so no performance gain in that regards...

[GewoW]

I had the long perforated pipe replaced with a straight pipe. The tin can sound is the stupid gopro. None of that IRL