j50nba

Please excuse my lack of mechanical knowledge,

I have just had primary and secondary cats hollowed out rather then removed (advised by the garage)

I still want it louder and the car has been booked in to have a silencer removed, but I have never read of this and only hear of resonator delete?

Am I better off getting secondary cats along with resonator fully removed to gain more noise or carry on with a silencer having baffles removed? What is the common mods in this area rather than replacing whole system

Will be grateful for any help / advice

BLKROKT

Resonator = 'silencer'

j50nba

I'm hoping this is what the garage plan to remove rather than the muffler behind the tailpipes then :/

Will this make much sound difference since -removing the insides of both the primary and secondary cats didn't make huge difference (only on higher revs)

INS1GNIA

Where do you live? A bit strange that the shop would suggest hollowing out instead of removing.

Be sure to check here first - https://mbworld.org/forums/c63-amg-w...-stickies.html

Headers and Exhaust
Anyone interested in American Racing Headers Group Buy?
Header Types Defined/Discussed + Photos of all C63 Headers and Manifolds
C63 Power pipe group buy thread
Header parts clarification
Exhaust info for a noob
*C63 AMG EXHAUST SOUND THREAD*
ARH Long Tube Headers/200 cell cats/x-pipe install

I've seen another member hollow out their exhaust but that was for a C63s. Not sure how much a difference it is from removing that part completely.

Removing only the secondary cats and replaced with straights will get you a deeper/louder sound while still keeping the AMG bark.
Removing only the resonators will get you a louder/a bit raspier sound.
Removing both the secondary and resonator will get you extremely loud with some rasp on it. Some like this, a lot think it is too loud.

j50nba

Thanks for your reply, I'm in the UK - I think the idea was to leave it looking stock.. Maybe?
I have just found a good thread on here giving detail of all the different options,
As far as I no now my car has had both primary and secondary cats hollowed out, which gives it abit more noise but mainly with higher revs, also pops more, my cars booked in to have the silencer removed which I now no is the resonator, I'm probably just best of getting the garage to remove the shells of the secondary cats at the same time and just replace whole section with straight pipes (if that'll make much difference) rather then only cutting out resonator and leaving the hollowed out shells?
It's also going in for remap shortly as engine light is on from removal of primary cats

rentzington

is it possible they hollowed the cats out due to some laws? I seem to recall another uk poster here before that mentioned the cats being hollowed out rather than being removed .

Glad they meant the resonator because I know in the uk they also call mufflers rear silencers

j50nba

It's possible although I have been told as both cats have been hollowed that it will still fail emissions test..not yet sure how true that is.

But that definitely explains my confusion between the resonator and mufflers

So il get the resonator removed (possibly with the shell of the secondary cats if it's worth it??)
And fingers crossed along with the decats I should be happy with the noise lol

sirius9

If you have hollowed out your primary cats, you will definitely fail emissions.
I am also from UK and some C63 owners here hollow out secondary cats as some MOT centres will fail MOT if they know and see that car has 4 cats originally and 2 has been removed.

If you hollowed out you primary and secondary cats and remove resonator, the exhaust will be VERY LOUD. Technically its a straight pipe.

j50nba

Yea I'm in Hampshire too- I guess il worry about that bit come the mot - slightly too late to worry now lol

And I think il make sure the resonator can be re-fitted just in case it's abit much then

cfoster

If its the same setup underneath as an SL55 removing the secondary cats (whilst still keeping the crossover pipe 'crossed over' will give you the noise you are looking for and keep emissions under control! I'm in the same boat, just bought a C63 (2010 PPP) and want it a little louder.

(From the UK as well!)

AMG3.2

Great post. OP - the first exhaust mod I did was remove the resonator. It still sounded way, way to quite.

Went back to the muffler shop literally 3 days later to rip out the secondary cats with straight pipe. This was much better! Not too loud at all in my opinion. No drone and totally civilized when cruising. I actually still think it should be louder...

Resonator delete with straight pipes is awkward since there isn't a connection point between the two banks of cylinders.

Resonator delete with an X-pipe alleviates the aforementioned issue but results in a smoother sounding tone.

Resonator delete with an H-pipe also alleviates the aforementioned issue, but results in a more aggressive bark tone. This is what I have and could not be happier.

Plenty of vids on youtube so search away!