Resonator is removed and....
For C32 owners.. Why is exhaust back pressure matter for you anyway?
Last time when I had cars with a forced induction engine(I've had Rx7, Supra, Audi), I tired to get rid of back pressure much as i can to gain HP...
I've been told that having much less back pressure can do some ill effects on N/A cars though..Removing resonator itself won't do no harm... period...
But with supercharged cars, the exhaust gases aren't spooled up and ejected at a enormous rate like with a turbo (where it sits on the exhaust manifold while the S/C sits on the intake manifold).
On JaredC43's C43 we removed 2 secondary cats and a resonator, the car sounds sick as well as we noticed a rather Large power gain. Some Mercedes N/A cars have a good amount of restriction, you can remove some things before you have to worry about back pressure. On his car there are still 2 cats and a muffler.
The Best of Mercedes & AMG
I took my C32 to a local shop to get the Resonator removed, they told me the Cat was within the resonator and it was illegal to remove it.
is this total BS? they seemed to pull up the diagram for the exhaust that showed the cat in the resonator?
with that in mind, how do i make sure i am getting the correct piece removed, i think i saw pictures on here before but i can't find them now.
thanks
I took my C32 to a local shop to get the Resonator removed, they told me the Cat was within the resonator and it was illegal to remove it.
is this total BS? they seemed to pull up the diagram for the exhaust that showed the cat in the resonator?
with that in mind, how do i make sure i am getting the correct piece removed, i think i saw pictures on here before but i can't find them now.
thanks
the C32 has 4 cats and a resonator...AMG-Jerry posted a pic or some other member/s do a search.....removing the resonator voids only the warranty and is not illegal to remove....
The simple fact of the matter is this --- An engine is nothing more than a big air pump. The purpose is to get as much air as possible into it and out of it as fast as possible. "Back pressure" is a myth I've been hearing about since I first started racing back in 1991, and I emphasize the word "myth"!
I've had 3 turbocharged Buick Regals since 1991, one of which I still own today ('87 Grand National). Being a forced induction vehicle the last thing on the planet I want would be "back pressure"! I cram as much air as I can into the motor via a large turbo, ported heads/intake, etc, etc! The results are a 231cid V6 producing 461 rwhp with only 18 psi boost, and capable of running low 11's or better w/ more boost. I also run an electric exhaust cutout/dump that diverts all exhaust straight out the side of the car before ever reaching the cat or muffler. The result of running fully open is 1/10+ quicker 1/4 mile times and 1.5mph higher speed at the end of the 1/4. Forced induction engines do not operate on an exhaust pulse as NA engines do, hence why mufflers such as Flowmaster don't work well on them, because of their pulse needing nature.
In order to buy my C55, I traded in my '99 Z28 w/ an LS1 383cid stroker motor. I also had an electric exhaust cutout/dump on it that yielded a 31 rwhp gain on the dyno vs. running it closed and through the muffler. Therefore, by opening up the exhaust I accomplished the following.
1. NO back pressure! 2. exceptional horsepower gains! 3. Very loud V8 tone. 4. and the difference in running 11.70's @ 115mph in the 1/4 mile to running 11.50's in the 1/4 mile @ 118+ mph. (best of 11.43 @ 119.85)
With the exhaust closed the car made 410 rwhp, and open it made 441 rwhp and 448 rwtq. All of this is dyno proven.
Exhaust valves do not need "back pressure" to aid in their function. They do use a scavenging effect, and simply need good springs, lifters, and a proper camshaft(s), and everything will fall into place just fine.
I had contemplated using a cutout(s) on the C55 to help pick up some hp and sound, however after seeing my friend's dyno testing with his C55 by removing the resonator and mufflers, the car only picked up 2 rwhp under the "power umbrella", but it did carry the linear curve a bit further before dropping off. This tells me MB did their homework for the exhaust as far as power is concerned, (assuming you keep the cats in place).
The only thing they really robbed us of is sound, which as shown above, can be resolved by the simple removal of the resonator.
That's my .02..........
Last edited by JToups386; Jan 29, 2008 at 03:21 AM.
I bought mine form E-BAY, for $25. They are a GREAT addtion and as you siad, I REALLY hated my arms getting poked by the cheapy plastics ones. The guy on E-BAY had them at my door in 3 days.
See yeah

http://cgi.ebay.com/ebaymotors/BRABU...spagenameZWDVW
Last edited by MRAMG1; Jan 29, 2008 at 07:42 AM.
The simple fact of the matter is this --- An engine is nothing more than a big air pump. The purpose is to get as much air as possible into it and out of it as fast as possible. "Back pressure" is a myth I've been hearing about since I first started racing back in 1991, and I emphasize the word "myth"!
That's my .02..........
I picked up 0.9 seconds in the 1/4 mile by removing my cats on my blown 91 stang. ANY forced induction motor DOES NOT NEED BACK PRESSURE as you pointed out. It simply kills performace.
See yeah
I bought mine form E-BAY, for $25. They are a GREAT addtion and as you siad, I REALLY hated my arms getting poked by the cheapy plastics ones. The guy on E-BAY had them at my door in 3 days.
See yeah

http://cgi.ebay.com/ebaymotors/BRABU...spagenameZWDVW

It will probably only void your resonator / exhaust warrenty.. but really.. what can go wrong?? Make sure you take your car to a good exhaust work shop.
AS for the resonator, I highly doubt that theres any ill effects by removing it. Stock resonator is basically a straight pipe with thick outer layer to tone down the exhaust sound.. By replacing that with a straight pipe will not reduce the back pressure.
My cats started going bad right around the time I wanted to install my Eisenmann exhaust. MB warned me to get the cats done first under warranty because weld-on mufflers would void the entire exhaust warranty. Aftermarket parts, not matter who makes them, Renn, Brabus, Kleeman, it can affect other parts of the vehicle which in turn can void warranty.
Every dealer could be different so I might be fighting for something that they would willingly do for you...it's an unknown.
As far as emissions testing...does the resonator affect the air quality of exhaust gasses or just the DB's?
Of course there are many of us who like a little rumble w/ our luxury, so we are able to achieve this by removing the resonator, etc, without any legal ramifications.
I have not gone underneath yet to look at mine, but when I do finally put it up on a rack I will see if I can use another straight piece of exhaust tubing to replace the resonator without any cutting or welding, assuming it's all a slip-fit setup.








