C63coupe

I went to the exhaust shop today and had the guy take a look the lift was occupied so he just looked under the car and said there are 2 primaries, 3 resonators and no secondary cats...? I was under the impression that the car had secondary cats also and I told him that he said we would have to see it on the lift.

My questions are if I want to make the car alittle louder possible horsepower gain if possible 1) what is the best thing to do, cut out secondaries and or resonators? 2) how much did you guys pay for these jobs. I.e resonator delete, or secondary delete or both together.

Thanks for input, planning on doing this soon

JCH

For my 09 I paid $100 to delete the resonator and replace with straight pipes. I like it, louder but no drone. Otherwise exhaust is stock.

C63coupe

Is there only 1 resonator?

E55 Bulldog

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Mort

There is only one resonator but it has two pipes through it and they are joined somewhere inside with a small H-Pipe. It can be replaced with two straight pipes. The secondary cats are before the resonator and in the best place to be replaced with an X-Pipe. Some have replaced the resonator with an X-Pipe. If you are going to replace them both (secondary cats and resonator) it seems best to replace the secondary cats with a X-Pipe and the resonator with straight pipe. I have done neither but hear it will be very loud. If you want an example of the latter then search _AMG_ as this is the layout he has and he has a write up and sound clip.

C63coupe

Very useful comment, thank you very much I think I'm just gonna replace the resonator with straight pipes. I'll post a video when it's done.

E55 Bulldog

From what I have read you would want to replace the res with some kind of x or h pipe. By removing the res you are also removing the OE h connector. Just to be safe you would still want some kind of cross over to equal out the air banks.

C63coupe

So with the h pipe, the crossover is enough to equal out the air banks correct?

With resonator delete and h pipe is there an issue of back pressure, causing loss of power?
How is the power situation, I'm not expecting ne thing I just don't want to lose any power haha

Merc63

Leave the resonator in tack unless you plan on replacing with an X pipe.

Remove the secondary cats to increase flow and sound.

C63coupe

And just straight pipe instead of secondaries, will there be drone without secondary cats?

C63coupe

Sorry about all the questions everyone, im just trying to make sure I do it right, I'm new to the amg scene, I appreciate everyones responses.

Merc63

I cant say for sure if there will be drone or not. I dont think so, but I bet there is a few guys on here that have it done.. You might find some videos on youtube as well.

I think removing those secondary cats is your best bet.

_AMG_

This car has 2 primary cats, 2 secondary cats, and one resonator.
If you want more sound out of your car remove the resonators and replace then with straight pipes. Shouldn't cost more then $100.

E55 Bulldog

There are 2 options.
- Remove 2nd cats and Res and just replace the cats with and x pipe into straight pipe to equal out air banks or I believe you can reverse that with straight pipe first in to x-pipe.

- Replace cats with straight pipe and keep the Res

I would go with an x-pipe over and h-pipe just b/c to me, air flow seems smoother.

As for the drone... Its all personal preference and what you consider drone. I don't mind a little drone in the cabin. Needless to say if you change out anything under there you will deff get a lot more sound.... good... bad... love it... or hate it... but it will be louder out of a car that is pretty loud already.

Its hard to get a feel for what it sounds like based on YouTube so I would say start a new thread asking if anyone in you area has this set up so you can meet and get a true sound of what you are planning on doing.

DuaneC63

+1. The resonator has two clamps on each side in the front but only one clamp in the back so you have to make a cut on one side to replace it. You might also be able to flare the cut ends and use a stock clamp so you could swap the resonator/straight piples out when you want. I've heard the resonator delete and it is louder but has a higher sound pitch. The secondary cats are down stream of the second set of OBD2 sensor so you won't throw codes if you remove them.

Or course you do realize that removing or tampering with a smog control device is both a federal and state crime punishable by a life sentence of driving an electric smart car for the rest of your life.

FastDonzi

just took out my resonator and replaced with straight pipes.i replaced the secondary cat last year.it sounds great.no drone at all in drive at any speed.great mod

oliver@velosdesignwerks.com

+1

c63insd

Just went over to check out how JCH's car sounded and loved it! I went straight to the same shop and got straight pipes in place of the resonator for $100 and could not be happier! (best $100 I have ever spent).

It keeps the same growl and sounds like stock just louder at startup and louder when you get on it over 2k RPM's. When cruising on the freeway it sounds exactly the same as stock.

I took some video and pictures so I will try to post a thread in the next couple days with before and after.

Thanks again for taking me for a ride JCH

JCH

Hey Julien - my pleasure. Nice to meet you. Anything I can do to raise the decibel level around here! Congrats again on your C63. Looks awesome. John