c63 amg sounds valved until 2.5k rpm's
 

Hello, I have a 2015 c63 AMG w204 coupe with weistec longtube headers, x pipe, and midpipe, and renntech stage2 tune
when I'm driving normally under 2500 rpm's it sounds a bit quiet for being full catless headers, but when it creeps up to 2500 rpm's i hear a steep increase in volume as it sounds like some valves have been opened.
Is this normal ? or what could be causing this, and how could I resolve this "issue"
I will try to get a video of this tomorrow and show you.
Thank you

Enjoy the fact that you can have dr jekyll and mr hide ;D

My first guess is your tune. Anyway you can flash it back to stock to see if anything changes?

I have a eurocharged tune and it does this. What's the problem? I like to be able to cruise around without droning.

Thank you for answering, and no there's no problem with it I just thought that something was off because thats the first time i've heard of this.
Thank you guys

if you don't like noise...best you don't reach out for one of my tunes then. :rolleyes:

possibly intake runner length change when the flap switches over

Could also be when the cam adjusters switch over which is most likely the same time as the inlet manifold flap changing.

This would be my guess, cams going up on lift/duration can affect the exhaust tone/volume fairly considerably. Intake shouldn’t make that much of an exhaust difference.

lift and duration are not changing this isn't vtec. Only Lobe separation angle is changing with camshaft timing. Definitely something that could change tone, but intake flaps do make a huge difference in a NA motor. Mostly what you hear in a stock car, especially noticeable in a none AMG Mercs with stock exhaust.

No it’s the same basic system an adjust moved the cam to allow the effective lift and duration to change. Yes the m156 doesn’t have 2 separate cam profile like vtec but it slides the cams to reduce the cam overlap as you increase throttle and rpm. At part throttle and low rom you have both intake and exhaust valves open to help with fuel economy and pumping losses. As you increase throttle this overlap is reduced. Still standing by my hunch it’s this and not an intake which if I remember correctly doesn’t change to the shorter runners until somewhere around 3500rpms