E550 resonator delete
 

I'm thinking about removing the resonator and replacing with straight pipe this Saturday. Got quoted at $160 for everything (which is okay with me considering the inflated prices in my area, NYC).

I'm nervous that it will be too loud. I read that the x pipe will be more subtle but not great for V8. If I go straight pipe, will it be obnoxiously loud? What about drone? I know there are probably other threads but they seem like ages ago, so I'm looking for some recent advice.

Resonator delete will not be loud.... youll pretty much notice it at full throttle only.
otherwise not much difference from stock is what i remember in my case.

Wait, why isn't an x-pipe great for V8, I replaced my resonator with one, should I be concerned?

I also replaced my mufflers and I have some crazy drone but I don't know if its from the x-pipe or mufflers or both :B

I don't think it's possible to make a blanket statement that an X pipe doesn't work with V8 cars, and depends more on cylinder firing order, naturally aspirated vs turbo car as well as other engine specific characteristics.
I've had a couple LS powered GM cars and in naturally aspirated form they sounds fantastic with an X pipe versus an H pipe or straight pipes. The vast majority of vette guys run an x pipe setup for good reason.
The turbo's on this car make a tricky and I too have been contemplating what to do, if anything with the mid pipe section. I purchaed E63 mufflers and thought about possibly leaving that as-is until maybe moving to catted downpipes.

Whatever route you go with, post up a video clip!

x pipe on the 550 turbo doesn't sound much different, minimal at most. I'd spend the $300 to cut out the mufflers and custom fab a ~29ish inch J pipe on each side for that price. Or a set of e63 mufflers would work too, they are quieter than just muffler delete but still has a nice growl to it.

It is a tough call bud! I paid ~$700 for my E63 mufflers so you would be halfway price wise.
Keep us updated.

My exhaust noise is very smooth, it's not raw or raspy at all. Has a very refined sound, but it's also very deep, you're not confused about whether or not it's a V8.

Before I had the x-pipe, I deleted the resonator and had Magnaflow mufflers installed, it sounded like an American muscle car but it had a really ugly idle sound so I opted for the smoother sounding x-pipe and different mufflers.

BTW I paid $400 to install the x-pipe and mufflers.

Interesting. I may look into and go that route. It looks like I may be holding off for now since I can't fully get on board with the x pipe. I just got the car 2 weeks ago and already spent a bunch on a grille, trunk lip, tints and V8 decals (not AMG just the V8 Biturbo). I feel like the sound is the last step to make me happy, but may need to hold off a month or so at that amount (~$700). Wifey may kill me.

Thanks, yeah I am trying to avoid the "tractor" sound at idle. I am sure I am over thinking it. I see videos online and the x pipes sound great, but I'm wondering if its because they are flooring it. I wish there were videos at normal acceleration speeds to see if there is a real difference.

I was lucky enough to find a member here with a set for sale $500. A shop was generous enough to charge me $60 to install.

Try to contact ebay sellers, before I bought my set I got an eBay seller to go from 800 to 600. Good luck with it if you choose that route. The 63 mufflers have a very nice non intrusive growl to it

The next "mod" on my list for my E550 is a vacuum actuated exhaust cut-out, located just behind the rear muffler. I just can't bring myself to cut off the stock mufflers because I know within a week I'd be back at the muffler shop welding them back on. This way I can have the noise on Saturday night but quite car on Monday morning.

I'm planing on going with this exact kit, since it uses clamps instead of bolts so i can rotate the actuator to better fit under the car:
https://www.ebay.com/itm/112956983439
(our car's are 2.25" pipes, so I'll need the shop to down size it from 2.5" to 2.25", all the 2.25" kits on eBay are all electric, which I don't want)

My idea is to use an Arduino board as a trigger for the opening of the exhaust flap. I plan on tapping into the LED on the Airmatic "Sport" button, so that when I put the car into Airmatic Sport and the LED comes on it will trigger the Arduino, which in tern will trigger the vacuum pump to open the exhaust flaps. When I push the button again for Comfort mode, the LED goes out (or to Comfort side) and the Arduino triggers the vacuum pump to release/shut the exhaust cut-out. Or at least that is the idea, it will take some fiddling and programming to get it to work.

Essentially I just want a factory looking "make car louder" button for my car like the new ones have.

I like that idea! Why the arduino though? You can simply use a timed relay actuator with a 5V input activation signal ( if you plan on using the LED on the center console). The only reason to use arduino is if you want to incrementally control the position of the flaps, but that seems like a lot of work. Really good idea with the activation on sport mode though, I'm kinda jealous I didn't think of it