Mr. J

There is substantial rpm change. Watch your tach!
And the burbles and crackle in the c450/C43 are a function of ignition timing.

Here's a better qualitative experiment. Show me where the divert valve(s) on my exhaust system bypass either the muffler or the resonators? Oh right, you can't because there is no bypass and there are no control valves. But if they were present, I should be able to force the valve into the open position (either vacuum or voltage controlled) and the exhaust would be louder regardless of drive mode. But you can't for two reasons.
1. There ain't no valve(s).
2. On the C450/c43 it just don't work that way.


With respect to the C63. I don't own one and I don't know a damn thing about the factory exhaust on one. It may operate in the fashion you describe. Or it may be powered by magical German bondage fairies for all I know. Regardless, it ain't germane to a discussion about the 450/43.

Dthquazi

Whoa pissy pants. No there is not a large shift in rpm during the closing of the valves during the high idle. You later admit you don't know anything about the c63 exhaust so get ****ed.

Second this is a mixed conversation. Not even specified that this was for the 450/c43 until later. Even then the comments made by pl27 and others were made in reference to the c63 so get ****ed again.

sean1.8t

Regardless of all that, Mr.j, your argument of "more rpms and different shift points" is completely invalid. Physics does not work like that.

Mr. J

Wow. You're a bit sensitive.

Take a look at the OP. His car is a C43. And Sean1 drives... wait for it... BINGO! YOU GUESSED IT! He drives a C450 too!

So anyhow, I'm glad I could help you figure that out. I know this car stuff can be a bit overwhelming at times. So I'm going to get back to F%@kin' myself now since my wife is already sleeping. Bonsoir buttercup.

Mr. J

Hey that's cool. Agree to disagree then. But don't drag my buddy Physics into this. He only tagged alone for the cheap beer and easy strange.


Got a question for you though. Is your Harley the only one that doesn't get louder when you open it up? Just wondering...cuz it's the same principle at work just on a grander scale.

Dthquazi

​​​​​​How about you teach me how RPMs and shift points would fundamentally change a tone of an exhaust. Also you would notice that my response wasn't really meant for the c43 guys including you. But you have to feel important and spout your stupidity over the place. I'm glad I could oblige you for the time being.

Mr. J

Thanks for the kind words.

Hmmmm lemme think.
I'll try to do this without dragging Physics into this. He's giving me some serious stink eye right now.

Think about a simple horn with no valves or keys. It's not much different than a straight pipe. If you blow through it with a specific emboucher it creates a note. You can change the note played by varying either the amount of air blown, the emboucher, or both. The horn stays unaltered. What changed is the frequency at which horn is vibrating and also the volume of the sound in decibels.

Similarly, as a motor revs at higher rpms the amount of exhaust gas and it's rate of flow increase. Also the frequencies that the motor vibrates at change with increases and decreases in rpm.

Overly simplistic for sure but it's relatively accurate.

Dthquazi

Well obviously. But what you are missing is that the tone of the exhaust would be set to specific RPMs. 2500 RPMs will give you the same tone throughout gears as implied by you. This isn't changed by the Ecu. Also if I'm being overly simplistic, the Ecu doesn't necessarily control rpm in the vast majority of driving. The driver does.

Also shift points have nothing to do with it.

By adding valves, that tone can be changed. 2500 rpm in comfort would not be the same as 2500 in sport+ (since you made it abundantly clear that you don't have race mode).

cenzo86

I think a couple of you guys need to pay closer attention to your cars. After the car is warm and you are stopped at a light, switch from comfort to sport+. Watch the tach and you will see a small bump in RPM. Once you roll away the more aggressive sound is all ignition and timing. The motor is making more power and making a more intense sound as a result.
Do a few searches and read through the c450 only thread. This subject has been discussed in depth. There is only a pipe with mufflers and 1 resonator under the c450, no valves to manipulate.

1Gunner

Can't speak to Mercedes.... until mine arrives in Feb- but what you say is exactly true regarding sound on my 991 Porsche Turbo. Push Sport or Sport+ and there's an increased difference in pops and gurgles on over-run... It's just not as extreme as I see on C43 YouTube videos.

But there is certainly no performance gain and I remain VERY doubtful there is with Mercedes as well. Throttle input mapping may become more sensitive, but that does not equate to increased power. It just feels like it!

Tej7

I don't understand why an argument regarding the exhaust sound even started after this was stated. This is the only explanation that was needed lol.