esqyankee

So I recently took a look-see under my car to look more closely at the cat-back Magnaflow (and understand why it's so loud) and I was hoping to get some advice. My two issues with the current set up are 1) it's too loud, too much drone and when you are slowing down in gear, it sounds like it's gurgling (this is a 550i, not a '72 Camaro, yanno?) and 2) I really want dual exhaust.

So, what can I do to address these issues? Can I simply check to see what part number the existing Magnaflow muffler is and add a second one to the passenger side and run a pipe up to where the existing y pipe is? As for sound, can I add resonator, and if so, where do I get that and where, exactly, would that reside in this setup?

Here is my current setup, look forward to your thoughts!

Boost7

A resonator will quiet it down, and get rid of the drone, you should look into the vibrant ultra quiet resonators and add one in the mid section since your muffler is already at the end.

You can get them from summitracing or any other sites.

Or any resonators of your choice will help reduce the decibels.

esqyankee

Great advice, thanks! How about going to dual, though? Is this just as simple as picking up a second magnaflow and running pipe back to the y-pipe, which would would pesumably be moved to behind the new resonator?

Boost7

Several options how you want to approach it.

Keeping your current muffler in place - then you can add two bottle style resonator at the y intersection and get an additional muffler and stuff that vertically next to the battery box. Then pipe it down to some dual tips. With this option, you will have to try to find some matching tips to your current ones already on the driver side.

Sell your current set up and do a custom quad - get a dual in dual out muffler for the middle section then out too two resonators one on each side, then out too some dual tips.

I'm not sure what brand you're settled on, but if you like magnaflow then just stick with them.

Or head over to your muffler shop and see what they can custom fab for you, they might be able to recommend something else that you might like.

Bobbrown13

That's my vote. You cant just put tin another Magnaflow like you already have because theres simply not enough room for it.

Sell the Magnaflow, get the 2in/2out and start with straight pipe to your tips. If it's too loud you can always add the resonators after. I put in two offset 4x8 ovals in both setting vertically. Didnt want it too loud.

I hope you kept your stock system, I would leave the 2 stock resonators in and build from there. I believe removing them is the main source of your drone.

Hyper_545i

I am running a dual setup. I have a Magnaflow mounted almost vertically on the passenger side near the battery box. I replaced the stock box shaped resonator towards the rear with a resonated Magnaflow X-Pipe.

esqyankee

So in the interest of not spending a crazy amount of money, does it make sense to add the vibrant ultra quiet for now (after the y pipe) and stay with single until I am ready, and then add the second magnaflow when the time comes (assuming that can be done)?

GForza

probaly depends on what you want to have for an end point. there are lots of threads on dual exhaust for the 545/550.if you serch you'll find all sorts of options:

https://5series.net/forums/e60-parts...st-545i-19663/

i believe there is still a system out there by RD Sport.
Rear Silencer Set-Quad Pipe Conversion BMW E60 545i 04-09

RD Sport Rear Silencer Set-Quad Pipe Conversion BMW E60-61 545i 04-09

pricey, but you could have a good muffler shop copy it and make ur own custom system, or look for a pre-owned system on the boards.

Hyper_545i

Get your self a resonator to cut back some of the sound. Your setup has omitted the rear box resonator that was present on the stock setup. See if that helps.

Boost7

yea, the vibrant ultra resonators will be the least expensive way to resolve your current issue with sound and droning. plus they look really nice. I got two of these, but haven't had time to finish my project yet.