I recently took my resonator off and I heard afterwards that doing so could cause a significant lag in throttle response. Now I may just be paranoid but I have been feeling a slight difference that is pretty significant to just be a figment of my imagination. Is this at all true? I would think that if anything it would cause less backpressure and thus more power if anything. Any help is appreciated. Thanks.

If you had a n/a 4 banger I'd be telling you something different, but I think you're being paranoid. The 211 E55 produces way too much torque to be affected that way. Take it to a dyno to be sure, but I don't think you have to worry about it.

No way does it cause a lag.... it just in your head. I seriously think tuners would not offer the procedure if it caused a lag in response.

I am not sure about the resonator deletes but I have a electronic cut out exhaust and when i open it up it feels slow as hell. I just do it for sound but when I am getting on it I run with it closed. I think it causes the supercharger boost to drop. Its especially noticeable when I am going from a roll. I wouldn't call it a lag in response but a huge drop off in power and torque. I think Vrus had the same feeling.

It's impossible to cause lag.. If you take off the resonators and look inside you will notice that you can see right through them. They are a straight through design. There is 0% restriction in the resonators. All they have is sound baffling qualities. Replacing them with straight pipes does almost nill for sound increase.

Did you do a X-Pipe or simply replaced the resonator with two straight pipes? The straight pipes hurt off of the line response. If you did that, you should switch to X-Pipe. If you look at your stock resonator, it combines the exhaust from both sides.

Yep, I just did straight pipes. Are you saying the straight pipes that replaced the resonator should be crossed? We have an X-Pipe on the Mustang but thats a whole system. I just wanted to delete the resonator. E55 Baller hits it pretty head on - it just feels as if I drop the peddle by about 1-2 inches while in 3rd at about 2k, the car barely responds. It takes a long time to pick up. Ive had this problem before and they had to replace some sensors but what are the chances of it happening right after I deleted the resonator...

This statement is simply NOT TRUE. I am not sure where you are getting this from. The inside of a resonator on a W211 E55 IS 2 STRAIGH PIPES. The pipes have holes drilled in them and it just happens to have a big casing around it for insulation and sound dampening.

The resonator deletes pipes are straight pipes just like what was there in stock form and will not affect performance/torque at all.

Does the stock system have a crossover any where in it? If there is then that would be an easy way to reduce back pressure and increase peak HP. Also scavenging effect would improve breathability.

There is an "H-style" crossover just before the secondary catalytic converters.

X-pipe works better and makes more noise then H pipe...has been proved in 1/4 on the same car...

Making ehxaust more freeflowing, you loose the boost pressure...

Those sensors that cause the car not to run at full power can be: Lambda sensors (O2), Cam sensors, throtles etc...

Does it sound better with resonators removed?

In a normally aspirated engine that is correct but for a forced induction engine the H pipe will make more power.

why is it that everyone here says it does not cause a slight reduction in low end tq when evosport and all the C32 owners have stated that you have a slight loss in lowend tq due to the reduction in back pressure. The lower back pressure causes the lowend torque to fall a bit but also is said to in crease high end power by a bit as well.

Maybe Vadim could discuss this because I know I have seen a zillion posts saying the removal of the resonator causes a bit of low end lag -- nothing drastic though.

Does the car sound any better? If not go stick the resonator back in!

How can there be a reduction in backpressure if the resonator is already 2 straight pipes?? Maybe on the C32 they are different... On the W211 E55 they are as I described and DO NOT contribute to any power reduction or increase.

They barely provide any audible sound level increases. Had I known what I know now I wouldnt even bother removing it... Unfortunately I didnt take a picture of the inside of the resonator otherwise I could illustrate what I am talking about.

On both C32 and E55 the resonator is simply a flow through muffler tuned to remove upper frequency resonance. You can see right through, sorry I only have outside pictures on E55.

When removed, there is a slight increase in exhaust sound. Since MBs are very well insulated from outside noise, inside the car the increase is very minor, however on the outside it is noticiable.

As far as power. On my C32, once headers and Stage II was installed, removal of resonator was worth 7-9HP, on stock car may be 2-3HP, mostly at the top. On E55s, we have not measured any increase. Perhaps as power level goes up, there will be several HP to be freed.

As far as lag. We have done now over 10 55s in the shop and frankly I have not felt any decrease or increase in driveability.

I have noticed, however, that DME adapts very well to one's driving style. Drive car slowly and it will be slow, drive it fast and it will be fast.

Vadim
Thank you, very nice info and pics
Josh

I think you better install H-pipe or X-pipe...

When exhaust gases join together, the result is better flow...

So straight pipes work better with E55K???

Anyone treid to put an H-pipe in place of resontatorsif it S/C engines make more power with H-pipe...

From my CLK and not from an E55, but I happen to have taken a pic of my resonator when I cut it off a couple weeks ago and it shows what you guys are all talking about:

OK..so I can just remove all the cats, resonators, get MKB stage 1, they can programm ECU for NON CATS mode and have around 550HP... sound good...

for Force induction cars, the less back pressure, creates higher tq and hp....

for N/A less back pressure you loose tq but gain a few hp on the top..


Vadim provided a dyno of a stock C32 with Green filters and no resonator, and the addition was 7lbs of TQ and 7 HP to the wheels.

There is no way a e55 can loose TQ. In fact, with green filters and no resonator, you should pick up a more TQ and HP.

At times, i don't want to step on it, since I don't want to sound like I'm showing off my car's exhaust, and it makes be driver SLOWER. I think this can contribute to feeling the car is slow.

I think Vadim is right, drive it hard 90% of the time and car will perform better.

Spoke to the gurus at Kleemann (Cory & Brandon) about 7 months ago and they noticed ZERO difference with a K2 car with with primary cats removed going into the stock system via secondary cats and reasonator(stock AMG exhaust is pretty darn good).

They did notice a slight reduction in TQ when straight pipes used from K2 install straight back and slightly louder.

That’s not entirely true from what I’ve heard any disruption in the Flowerstock flow from the exhaust can cause some decreasing back pressure or what would otherwise be let’s call them trapped gasses. Because they are escaping a lot faster now hence a higher flow and less reduction in exhaust gases I’m not sure though how this equates to low-end torque but it does affect the torque by removing out of the resonator or muffler both plural because there’s two on my particular ML

what I am being told is that as a result of having increased flow and freeing up those gases that there may be a required tuner to make adjustments but I would think with the sophistication of these computers that they would make the adjustments almost immediately