2008 Z4 3.0i Muffler Delete

[Manners226]

So 1st off if you just wanna tell me how dumb this idea is, just save yourself some keystrokes and move on, because I don't wanna hear what you think about it.

With that said! I got the car up on a rack and talked with the tech at the exhaust shop about what I want to accomplish and if he felt it was something he could do cleanly and I think we came to a good understanding today. I'm gonna have it done next week. We will cut the exhaust about ten inches from the back of the muffler, do a short Y pipe into a single 2 1/4'' pipe, then end it at the bumper with a twin outlet Y tip. The Z4 has TWO pipes going into the muffler, unlike the E90s that use a single, hence the 1st Y, but it will look almost just like this...



I went to the dealership today and look at the parts cpu diagrams on the E90 328i, E90 325i, and E85 Z4 exhaust systems and the are all pretty identical short of the routing. The N52 motor in these cars uses a Cat in both manifold pieces (3 w/ a cat, 3 w/ a cat, all to make one 6-cyl manifold) so two Cats up front, two more Cats about halfway downstream, a center resonator (or Pre-muffler) THEN the big clunky rear muffler at the back.

This is a lot of backpressure/sound suppression. So since all of the E90 guys have had good luck and noone makes a great exhaust for our Z4s I'm doin the muffler delete. It will be done with a careful cut so that it can be put back to stock as easy as possible if need be. This is what I expect the car to sound like when done... (poss a little louder b/c the Z4 uses a smaller final resonator, but pretty close)

I haven't heard of anyone doing this on a non-M Z4, so it should be fun! Oh and it's gonna cost $150 bucks.

Here is the car now...

[Incompatible]

Manners226,
If you will, do a before and after recording of the exhaust. Same video camera, distance, location..... That will provide a somewhat valid comparison for the variety of different computer speaker/sound setups.

Very interested in your results. If I understand your post, you are removing only the rear can (muffler) and leaving the exhaust manifold cats and the two inline resonators? Why did you decide to go with a 2 1/4" pipe instead of 2 1/2"? TIA

[Manners226]

I plan on taking some pics and similar videos out in the open for comparisons sake.

Yes, only removing the rear muffler, nothing else. 2 1/4 b/c thats what the inlet on the tip will be. I don't think a 1/4'' will matter for only a foot of pipe.

It's nothing crazy, just taking the muffler off, but I can't find another non-M car Z4 that has done this.

[Incompatible]

Originally Posted by Manners226

I plan on taking some pics and similar videos out in the open for comparisons sake.

Yes, only removing the rear muffler, nothing else. 2 1/4 b/c thats what the inlet on the tip will be. I don't think a 1/4'' will matter for only a foot of pipe.

It's nothing crazy, just taking the muffler off, but I can't find another non-M car Z4 that has done this.

Thanks. Awating your followup posts.

[BossE86]

I'm interested in this as well.

[jra]

what are you doing in regards to the tips? When I had my remus exhuast the exhuast tips were a tad under 3.5. I'm doing a muffler delete with headers soon, going with the dimisa 3.5 tips.

[Manners226]

Something like this... Maybe with a slash cut instead.

[Jaydon Fabulous]

Does anyone know the piping diameter of our stock exhaust?

[Incompatible]

Originally Posted by Jaydon Fabulous

Does anyone know the piping diameter of our stock exhaust?

1.880 inches outside diameter at axle location

[Jaydon Fabulous]

Thanks for the quick response. Wow, small pipes. If i take my car to an exhaust place can they fabricate 2.5" piping to fit up against our stock piping? I'm looking into the muffler delete as well, and the tips i want to use have a 2.5" in. Sorry i'm a noob at custom exhausts

[Incompatible]

Originally Posted by Jaydon Fabulous

Thanks for the quick response. Wow, small pipes. If i take my car to an exhaust place can they fabricate 2.5" piping to fit up against our stock piping? I'm looking into the muffler delete as well, and the tips i want to use have a 2.5" in. Sorry i'm a noob at custom exhausts

Y pipe should be no problem for a competent muffler shop.

[Chris04Z4]

THANK GOD!! Someone with a 3.0i is doing this!! I cant wait for the feedback!

[krnnerdboy]

I've gotten that done on my z4m and love it but was thinking of doing the same on my wifes e90 328i. The feedback has been great who have done it and I expect similar results w/ the z4. kudos

[Incompatible]

Originally Posted by krnnerdboy

I've gotten that done on my z4m and love it but was thinking of doing the same on my wifes e90 328i. The feedback has been great who have done it and I expect similar results w/ the z4. kudos

Any before/after video?

[Chris04Z4]

updates"?

[Manners226]

It's DONE! Came out better than I expected. Sounds stock at idle then gets that straight 6 roar as the RPMs build. It's is not anywhere near as loud as I was expecting, which is great. Crusing is normal, no drone at all. It really, really came out great. Never would I have guessed a muffler delete could sound so clean...Pics and Vids tonight.

[Chris04Z4]

(starts looking for the Zip Wheel) Looks like i'll be doing some cutting tonight! might look a little odd with no tips coming out the back but thats ok for now... im sure a muffler shop could weld on some tips for cheap.

[Manners226]

Sorry for the crappy video, I took it with my digital camera...

[Chris04Z4]

U Fn Rock! thank you for the vid!!!

[Manners226]

I'll get ya something that doesn't suck up this weekend. It sounds deeper and meaner in person.

[Jaydon Fabulous]

Sounds mean

Notice any performance increase on the butt dyno?

[Incompatible]

Originally Posted by Manners226

Sorry for the crappy video, I took it with my digital camera...

By any chance did you do a stock muffler (before delete) vid for comparison? It does sound good.