Capn

I've got the resonator delete but I still think the car sounds too tame. I don't want to remove the primary+2nd cats because of smog in California.

What options besides adding headers and custom piping from the 2nd catback can I do to increase the sound?

The sound I'm looking is like the C63 preferrably but probably not possible.

Quicktwinturbo

Bigger pipes / tips might help..

91RS

There are people on here who've had no problem removing the secondary cats on CA. You'll be happy you did.

Capn

I think most people who removed their secondary also had the resonator delete and had some droning. I commute 45 mins to work going 15-25 mph

I believe I can get away with swapping in a 200 cell cats on the secondary and staying smog legal and eliminating the drone effect. Question is where to find 200 cell cats and what is a fair price for a shop to install these?

91RS

There's no drone without the resonator and secondary cats. I had my car like that for over a year. I still don't have any drone with Kleemann headers and two tiny 100-cell cats and custom pipe to the mufflers.

ghiaguy

I just removed the secondaries this weekend after running without a resonator for six months. The resonator removal alone created somewhat of a muted growl once removed and for quite a while I was happy with that.

I commissioned a tailored Eurocharged ECU tune and specified deleted secondaries since I figured I would do it down the road. I drove the car for a month delighted with the tune and still holding off on the secondaries. After seeing enough stock C63s, E63s, CL63s etc downtown- I began to have sound envy. I finally did the secondaries and I really don't see why I waited so long.

There really isn't any drone like I expected- it really shouldn't be regarded as a drone though there are rpms that emit a steady low growl. The noise on throttle is not unlike a C63 (though maybe not as polished) WOT is just right- It lets you know it is not stock and establishes the performance credibility that the C55 deserves. It sounds like a proper modern AMG V8.


I cannot see achieving this kind of sound without removing the secondaries- To do that you would have to go with different mufflers and I have always heard that the C55 mufflers are something worth keeping.

Capn

By removing secondary cats would you fail a visual smog inspection? What about an emissions test?

If you don't mind telling me what the removal of the secondary cats cost?

ghiaguy

I have never had a visual inspection in which the techs actually get under the car, so visually it will be fine. Since I have just gotten it done I cannot attest to whether the car will pass the sniffer, although other members experiences have been positive enough for me to take the plunge.

It was $100

MBNiko

Just do it! Nothing else will really increase sound.. I have 2ndary and resonator off and theres no drone, it sounds great. Throwing Kleemann headers on in the spring time though b/c I like extra loud

C_DirtyTwo

One thing that might increase the sound a little is a true dual exhaust. But like everyone said before, delete the secondaries, it sounds great.

my car passed CA smog with no problems without a res or secondaries.

speed7

Ok I'm going to do this now too.. Any pics of the exhaust before and after?

ghiaguy

I read that the car will take a little time to "learn" that you have modified the exhaust before it takes full advantage of the reduction in back-pressure. I have a flashed ECU, but I was just curious if people noticed that the car came into its own after a little while cat-less. Any changes in performance/feel/noise after some time? I have only had the secondaries removed for two days and am really happy already!

Capn

Personally I love the sound of the stock SL65 exhaust, just need to fit a V12TT into the C55.

ghiaguy

No pics here, but don't have any trepidation that you may remove the wrong item... The two secondary cats are side by side at about the middle of the car, just before where the two exhaust pipes come together. You will be surprised to see how far forward the primaries and O2 sensors are! The resonator (I don't know if you've touched it yet) is the large cannister further down after the pipes merged into one.

ghiaguy

Haha! Removing the secondary comes pretty close. It definitely creates that deep tone without sounding like an american truck w/ flowmasters. Sign me up for that V12 though!

Capn

Searching the forums, here's the break-down of HP/TQ gains...

Summary of some of the NA 55 AMG 2nd cat dynos:

AMS 300cell 2nd cats = 10HP / 12 TQ Dyno Dynamics
Hooley 2nd delete = 13HP / 19 TQ Dyno Dynamics
Bryan's 2nd delete = 16HP / 22 TQ (dyno unknown, maybe dynojet?)

Capn

Now I'm curious about how much sound is increased with the following setup from 1 to 10 range. We'll set the stock setup at 1:

1) Stock = 1
2) Resonator Delete = ?
3) 2nd Cat Delete + Resonator Delete = ?
4) Primary Cat Delete + 2nd Cat Delete + Resonator Delete = ?
5) Kleemann Heaeders + 2nd Cat Delete + Resonator Delete = ?

ghiaguy

Ill take a stab:

Capn

Has anyone gutted their mufflers?

91RS

I've thought about it. I think I've heard of at least one E55 guy that did that.

Capn

Yes, if I'm not mistaken he's selling it in the classified forum here.