MerlinMc

Several of the C55 owners on this board have talked about removing your resonator. If anyone has done this, can they share their thoughts on this modification? Thanks.

TEAShea

I had mine removed two weeks ago. I nice little mod. A little louder and deeper sound. A little weight savings. It cost me about $40.

Tom Shea

cntlaw

I heard many did this too. My only concern is would C55 still sound a C55 AMG or we end up with 'cheap exhaust sound' that it is never a Mercedes again? And when it means louder, does it bother you when you are in the car when wants to listen to nice music some times?
Otherwise, I am quite comfortable about this.

BTW, where is the resonator located?

BlackC230Coupe

No, the car will never be that loud with just the resonators removed. It will still sound "Mercedes". :p It should be heard in the cabin when you are curusing. Maybe just under acceleration.

KompressorKev

i don't have a c55, but on c32 it is a fairly common mod. should be around $40, no more than $100. i think i might need to remove the resonator, my car is so low that sometimes coming out of steep driveways my resonator scrapes the ground!

BenzoAMGpower

car would sound only a tad bit louder on WOT... but i would leave them alone unless you had some kinda ECU tuning to compensate for them!!!

430

What???? Do you really think that removing the a resonator is going to necessitate a new ECU or are you just having fun with the guy?

The resonator will give you a couple of HP but nothing to write home about. There will be no issues with the ECU, even if it could not compensate.

BenzoAMGpower

well I dont know about the 11.0 compression M113, but i ****ed with both the resonator and my rear cats on my ML55 (10.5 compression M113) and though I felt it reved faster at higher RPMs, I definately felt it loose torque!!! I put back the resonator and It felt a little better!!

Bernanke

back pressure is not an issue on forced induction cars.

cntlaw

Sorry I am a car mechanics idiot.
Is the silver " cooling fan like " component sticking out in the bottom of the car the resonator ? I noticed this 'thing' long time and don't know what it is. And, why I never saw them in other cars I owned?

cnt

rguy

That silver thing is almost positively your rear differential. The fins are to act as a heat sink so that your rear end doesn't overheat during hard driving sessions.

rguy

A resonator is a part of your exhaust system and looks very much like a second muffler that is closer to the engine in your exhaust system than the mufflers with tips sticking out the back. What people are probably doing is cutting out the resonator and welding new exhaust piping in where the resonator used to be.

This causes less resistance to exhaust flow and should give you lower exhaust gas temperatures (good for lots of things in your car), lower backpressure and subsequently more horsepower (or engine efficiency).

I hope this helps you out some. As far as I know the purpose of a resonator is to further muffle sound and to change the frequency of an exhaust gas pulse so that it does not "resonate" (vibrate) with the vehicle and cabin. Some poorly designed exhaust systems cause very annoying vibrations to enter the cabin and are generally unpleasant to our ears. Resonators are generally employed for this to my knowledge. If anyone has a better explanation or has heard otherwise, then speak up. There is exceptionally low amounts of information about resonators published.

cntlaw

So the " silver thing with fins " I saw sticking out from the bottom of the car is not the resonator but it is the differerntial (what ever it means).
Since as now saying the removal the resonator will give more unpleasant sound but better horsepower/performance, I would probably not need to do it as I do not go to tracks. It may be tempting to get a deeper exhaust sound than my C55's present form, I would stick with the original for a while.
Wow. A lot of information here. Thanks.
cnt

BenzoAMGpower

less backpressure isnt always good... its only good when you have forced induction if the proper adjustments are made!!! With N/A setups, you may gain HP but u could loose whats more important...low end torque!!! The AMG motors are tuned for the amount of backpressure you already have with your exhaust and the AMG exhaust flow really well already anyways.

BlackC230Coupe

I dont think removing the resonators actually adds any HP on our cars. I know the C230 coupe C7 package came with no resonator and the regular one had a resonator, and the ones without the resonator didn't have a gain. Its mostly just for sound.

BenzoAMGpower

it may be an issue when you have a C32!!! Freeing up a lot of backpressure w/o programming your transmission to change its shiftpoints to a higher RPM could restrict what power you could have gained from freeing up all that backpressure. Remember you do gain power on forced induction cars by freeing backpressure but it makes no good when you cant get to that power (due to the fact that your powerband does move higher in the RPM range, even though you get there faster, you wont be able to use all of it as your transmission will shift too early). I wouldnt mess with my exhaust too much, the only thing id do is change out the muffler for an Eisenmann...that is unless I get somebody to change the shiftpoints on my transmission and dyno tune it ::cough cough::RENNTech::cough cough::!! Freeing up a little backpressure could help to a certain extent but freeing up major backpressure (i.e. removal of rear cats and resonator) should require proper tuning.

KompressorKev

benzoamgpower - as a side note eisenhaus did tell me the race version did reduce slight backpressure but they certainly kept in mind that you can't lose too much and they said the race version is at the optimum combination of free flow and necessary backpressure. they did tell me that using freer-flowing stuff in addition to the exhaust wouldn't help unless i would compensate with ECU tuning. so seems like they took this into account.

i am glad they didn't just free up as much backpressure as possible in the gain for bragging rights as the freest flowing system, but i think it's a nice addition to the c32. i definitely don't think it hurt performance at all, so i would guess eisenmann is right?

BenzoAMGpower

and they are correct... its the point ive been trying to get through!!! which is why i dont want to deal with any "custom" exhaust Id put together unless it was tried and tested (which Eisenhaus has probably done).

430

Ahhh, that explains it. The removal of your cats is what caused the 'issue' (your loss of low end torque).

As far as the whole not enough back pressure and loss of torque thing. There are 2 different camps on this issue. One side feels that there is no such thing as too little backpressure and the other feels that a certain amount of back pressure is needed to maintain low end torque.

99e320

oh here we go with myths of low end torque loss with cat delete . all false if you gut ur cat thats will kill power, if you replace your cat with oversized pipes that could also. but if you use the same stock piping size ur fine. i did it with my ls400 and it is night and day difference.

so in essence remove your 2 rear cats the ones w/o the o2 senor behind it. and/or your resonator you will notice a difference. sound mostly with resonator, if you do the rear 2 cats you will def. gain some power and be legal. 2 cats is plenty.

benzoc55

do it ! i did it like 2 months ago and i am very happy with the sound and it is a lil cheap mod you can do.

dorikin_86

anyone know what size pipe I need to buy in order to do this myself?

thx!

john89011

Removed the resonator yesterday. The guy tried it with a saw first but it would not even make a dent so he used a torch. It took him about 30min and $100 to do it. They used a 3 inch steinless steel pipe, sounds great!

Pgpatel2

Hey guys, I have a problem with mine, seems like my car got slower or lost low end torque? How can I fix this? I deleted the secondary cats Y pipe to the deleted resonator and straight pipes to the muffler, seems like my car don't pick up like it used to :/
Ahh help me please!

Thanks