CL63 AMG 6.2 2008 exhaust mod

[Cipollini]

I know this was discussed many times and general consensus is to replace resonator and secondary cats with straight pipe.
I was willing to do that without posting this thread, but it looks like my car doesn´t have secondary cats and has some H-pipe between resonator and primary cats

Sorry for bad pics, I just lifted the car using lift button and tried to make some pics from the ground.

To me the exhaust layout looks like: Exhaust tips --- Mufflers --- Resonator --- H-pipe --- Primary cats
I can see no secondary cats anywhere.
Is this factory w216 exhaust, or someone has already removed secondary cats? I think the exhaust looks like original. The same pipes and rust everywhere.

So what are the options for modding my exhaust? I can see only one: to replace resonator with straight pipes. Or is there anything else I can do?

My goal is to make it noisier outside and inside the car, but still keeping the typical AMG sound and bark. During first week I really enjoyed the exhaust sound but now I think it´s very muted for 6.2 AMG.

Thanks

 

[V6Matty]

The H pipe isn’t factory and has been added in (pretty well looking at the pictures), the rest does however look factory, the rear muffler as you call them are also the rear cats I believe so to get more sound you’ll want to remove them, but you will cause a drone.
Personally I’d take it to somewhere that does exhausts for a living like Tourqueflow in Birmingham, they can get you the exact sound you want and ensure it won’t drone

 

[Cipollini]

Thank you, but I´m not from UK. Anyway I can contact them for some advice if they are helpful.

I don´t think the rear mufflers have any catalytic function, therefore they can´t be called cats. I am pretty sure the AMG rear mufflers work like amplifiers so I wouldn´t want to remove them because the AMG sound may be gone.

I don´t see many options here. Removing primary cats may do the job, but I wouldn´t pass the MOT.

 

[V6Matty]

Thank you, but I´m not from UK. Anyway I can contact them for some advice if they are helpful.

I don´t think the rear mufflers have any catalytic function, therefore they can´t be called cats. I am pretty sure the AMG rear mufflers work like amplifiers so I wouldn´t want to remove them because the AMG sound may be gone.

I don´t see many options here. Removing primary cats may do the job, but I wouldn´t pass the MOT.

Sorry missed you weren’t in the UK,
Hmm maybe I’m wrong then that the mufflers also had the cats in them, could well be as it’s been a long time since I looked at exhausts

 

[daveenty]

By the looks of things from the photos you have posted, the secondary cats used to live where the H pipe is now. As far as I'm aware, that H pipe is not a standard fit for a 156 exhaust.

The central resonator could be replaced with straight pipes (this is usually where the H or X pipe go) but will do little if anything for performance and has the potential to create a droning noise. Removing the rear boxes would be a nightmare for both noise and drone.

The most common option in the UK, at least for the C63 with this engine, was to replace the standard headers with long tube ones for better gas flow.

 

[alexanderfoti]

H Pipe is standard on these. The primary and secondary cats are both integrated into the same can on the downpipes (which is why the secondary O2 sensor goes in the middle of the can)

 

[Cipollini]

H Pipe is standard on these. The primary and secondary cats are both integrated into the same can on the downpipes (which is why the secondary O2 sensor goes in the middle of the can)

Didn´t know about this, I was sure the secondary cats are separated and could be easily removed (like commonly discussed in M156 exhaust mod threads).

Do I have any options what to do with my exhaust sound? Of course except installing long tube headers, I´m not willing to spend that much on it.

I don´t think that removing primary/secondary cat cans would be a good way to go. I have no idea why the CL doesn´t have secondary cats isolated like C63 and other 6.2s
Very limiting solution...

 

[alexanderfoti]

Didn´t know about this, I was sure the secondary cats are separated and could be easily removed (like commonly discussed in M156 exhaust mod threads).

Do I have any options what to do with my exhaust sound? Of course except installing long tube headers, I´m not willing to spend that much on it.

I don´t think that removing primary/secondary cat cans would be a good way to go. I have no idea why the CL doesn´t have secondary cats isolated like C63 and other 6.2s
Very limiting solution...

All 221/216s are like this. MB don't care about the modification options when they design it

Removing the resonator will give you more noise, and I suspect will be what you are after. It will drone about 10%-15% more but will not be noticeable.

LTH will need sports cats to pass emissions which is ££££

 

[Cipollini]

That´s for sure The exhaust is great already from MB, but still... it´s 6.2 and CL´s interior is incredibly well isolated from outside noise. I can hear the exhaust only with windows fully open.

I will remove resonator, do you have any advices for doing it? Straight pipes? H-pipe? Bigger or smaller diameter pipes?

 

[Cipollini]

All 221/216s are like this. MB don't care about the modification options when they design it

Removing the resonator will give you more noise, and I suspect will be what you are after. It will drone about 10%-15% more but will not be noticeable.

LTH will need sports cats to pass emissions which is ££££

Today I let the local tuning garage do the exhaust job with removing the resonator.
I hope they will do good job.

 

[AMGeed]

Straight pipes are fine to replace the resonator.

 

[Cipollini]

Straight pipes are fine to replace the resonator.

Yes, it will be done that way. I discussed it with shop and they said that one H-pipe is sufficient. They will cut off resonator and install straight pipes with slightly bigger diameter.

 

[bembo449]

i had a 500 model 216 and I simply cut the rear boxes open and replaced the pigs tails with straight baffle pipe , I had to add a bit of extra wadding too , I really like the results and I cant say I got much drone with that set up

 

[Cipollini]

So resonator was replaced with standard 2mm thick steel straight pipes from hardware store.
Actually I didn´t expect the sound to be very different from stock (considering the shop didn´t touch cats and rear boxes), but the difference is impressive.
The volume and raspyness are considerably higher, but luckily it doesn´t drone, at least my ears didn´t notice yet. The AMG depth is still there, maybe a little bit muted, but it could be just masked with much louder sound.

Cold start is insane and overall I can say I wouldn´t want any louder exhaust than it´s now. While driving the CL cabin is very well isolated, but when I open the windows I understand why people turn the heads . The sound inside the cabin is just slightly louder, but no doubt it´s really LOUD outside.

The only complaint is that I can hear a very little bit of a ´metal´ sound coming from the bottom of car when revving the idling engine. Maybe I should use standard thinner exhaust pipes, but I´m not sure it would make any difference. The shop said the new pipes just need to settle and carbon up and the sound will be 100% ok.

Overall I can recommend this mod as I didn´t lose typical AMG bark, it´s just louder and more attractive.
It´s CL-Klasse after all, but this engine deserves to be heard, otherwise I´d buy CL500.

Compared to my friend´s Maserati I think the CL63 now sounds better (he said so too).

I will post photos and video later.

 

[Cipollini]

Some pics taken during the mod. Not the cleanest looking job, but not so bad for 100 bucks including material.

Reputed exhaust modding company quoted me 800 for the same job (although the result would look nicer for sure).
I also told the shop to install a bit longer pipes than resonator to make the nice chrome AMG tips a bit more visible.