Your wagon is easily the best sounding N54 I've heard in any platform, no raspyness and more turbo spool noise than I've ever hear before. Do you have a build thread or some details I can look at to copy it? Is there something about the wagon that makes it different? I WANT this noise lol.

 

https://5series.net/forums/e61-touri...ve-all-135223/

 

I lucked out with the exhaust build, conceptually the design makes sense but I have heard many other single-pipe systems which don't sound good, I attribute it to the fabricator and clean work. The turbo spool is my favorite, part it HOWLS, I love it.

The build thread linked in the last post is great for all wagon mods but this may be more helpful for exhaust specifics.

Evan

Pictures, Video, and Details of my Custom Exhaust System. - N54Tech.com - Your Source for International Turbo BMW Racing Discussion

 

Thank you! I have worked my way through most of your build thread, great work, so much detail and the detours you take to get it just right is what this is all about!

Right now I Just have muffler delete, I do think it sounds better than average for the same reason. Very clean piping from the axle back through the tips, somehow if it looks cleaner, it sounds cleaner. I'm sure there's some physics to back that up . However, I don't think I'll be going catless anytime soon, I used to swap the whole system in and out for smog in my Subarus and I just don't feel like doing that on the BMWs I'm thinking of leaving all cats and going as big and smooth as possible straight back. 3, possibly 3.5" from the rear cats through to the tips (No resonators). Are you aware of anyone running this set up?

 

When I referred to clean, although design simplicity is important, I was mainly referring to pipe junctions and welds (skilled fabricator).

I have never heard of anyone running 3 or 3.5" from the 2ndary cats. It would be an extremely awkward setup as the piping from the DPs to the 2ndary cats is oem and about 2.4" or so, not to mention cats would be a huge bottleneck for flow and would negate any potential gains from the larger piping.

Evan

 

For the purposes of "gains" I'm sure you're dead on, an exhaust is only as free flowing as it's most restrictive point of course. I'm not looking for a 500whp daily like you, I'm just not prepared to deal with the cost and potential nightmares that come with building it. But for sound and character purposes, I would think that it wouldn't be any more "awkward" than a typical Cat Back system, possible much less awkward since the pipe would include much less corners and angles than any which includes a muffler, resonator etc.. as even the high end cat backs do. Having the exhaust echo around inside a 3" pipe for 6 feet has to improve the depth of sound over just keeping the 2ish OEM tubing with simply a muffler delete. I'll give it a shot and make sure to post some clips, I'm not expecting anything close to the sound you've achieved, but hopefully a little more bassy than the typical muffler delete.

 

Evan,

How loud would your exhaust be if you had catless downpipes, and a muffler delete? I currently have a cobb stage 1 tune and some cone intakes. Also would adding just the catless downpipes alone add a big difference to the sound?

Thanks man

 

Took my car to my mechanic, and all he said was "I got you". I ended up with the same pipe split which looks nice. The only problem I am facing now is that I live in California and I might not pass the smog test.

 

I think it sounds awsome doing it to my 2010 535i xdrive N54T E60

 

I've got a 2008 528xi... did duals, from cats/headers back. I didn't want to go too loud, so I had them cut out the OEM res and installed dual res underneath to dual pipes. I had previously done a muffler delete.

https://5series.net/forums/e60-e61-p...3/#post1607652