busta55

Does anybody have C55 with all 4 cats deleted and x-pipe putted were resonator should be? All I found is 2 youtube videos and nothing is clear after watching them. I'm scare that it's would be too loud, nascar sound..
I have all 4 cats + resonator deleted now, thinking of x-pipe, please advice guys

MJ50

just do 2nd cat delete and x-pipe...

busta55

I wrote already, all cats deleted already (by previous owner).
So, does anybody have c55 with all 4 cats deleted + x-pipe and how it sounds?

///AchMeinGott

There's an underside shot. As you can see, the secondary cats are much further back and parallel with the rest of the exhaust. It requires minimal skill/time to cut from in front of them, back to the muffler pipes, and install piping/X-pipe. The main cats essentially are attached to the exhaust flange, so they'd have to be cut off and reattached, you'd have to replace the down pipe(ing), and need 02 bungs made. Nothing extreme, but time consuming and not worth the added effort to me unless you're doing long tube headers... in which case half of what I said is taken care of with the headers.

///AchMeinGott

Completely misread that too lol. If it's straight pipe'd now, the volume won't change much at all, as you're not adding anything to muffle/amplify sound. The pitch will probably go up though in the upper rpm range. Less rumble, slightly more scream.

thtguy

the only point of an x-pipe would be if you are going dual all the way to the back. is that what you are doing. if so I would recommened an X with an H cross just behind it, I have heard that will effectively kill the droning happens at higher speeds. something I am working on doing.

///AchMeinGott

There's the solution.

busta55

guys, thanks for the replies. But still.. anyone got true straight pipe exhaust with an x-pipe on C55? I want to hear it!
2 videos I found:
and I don't like the sound at all. Maybe because it was filmed in garage or somethin'. Need to listen drive by.
H-Pipe: but not written cats are in place or not.

Smokey31

From my research on the matter, the best solution for the C55 is to leave the primary cats in place, delete the resonator and replace with a x-pipe and delete the secondary cats. Surely its too loud with no cats at all? Will sound like a chav with a Subaru.

thtguy

so just to be sure, we understand... you have stock manifolds, with pipes replacing your both sets of cats, going to a y-pipe into a Single straight pipe that replaced your resonator which then goes back to the y split going to your dual mufflers... if I have this wrong please explain in detail... pics if possible.

And as I said previously... X pipe is only useful if going dual all the way back.

busta55

Exactly, stock manifolds, pipes replacing both sets of cats and a single straight pipe replaced resonator. Do you think it is worth to go with the x-pipe and dual all the way back? My goal is more nicer exhaust sound and not to loose any HP.

///AchMeinGott

You won't loose any power whatsoever. Don't buy into any "backpressure" talk, what's important is exhaust scavenging. That happens primarily in the headers, but the X pipe will also help, allowing gases from one cylinder bank to fill up either, rear exhaust pipe. It won't make it louder, just change the pitch.

thtguy

if you are getting any droning at highway speeds, the x-pipe and dual all the way back can help that. I agree with ///AchMeinGott it won't be louder, but it will change the pitch.

91RS

Brezza AMG

is this your setup?

is that spacers that i see for the rear O2 sensors? am contemplating going the headers route, but dont want to run into any issues with CEL.

i am in Aus and dont really fancy sending my ECU overseas to get the code removed.

91RS

That was my old car, yes. Someone else is enjoying that exhaust now. Kleemann mid-length headers, Random Technologies 100 cell cats, and fully custom 2.5" stainless steel from there back into the stock mufflers. The car was supercharged before that exhaust and I gained a half of a second in the quarter. It flowed! The rear oxygen sensors were just in standard bungs but they were turned off with STAR in developer mode.