This is kind of a silly post, but I noticed something today. First I have a 2017 C63 AMG that came with NON PE and I have a Stage 2 EC Tune. I got an AWE Track Exhaust first and liked it, BUT, it did DRONE a little and then Purchased the Swithpath Adapter Kit and had an exhaust ship install the exhaust and then I wired up the Electronically controlled Exhaust Valves myself as I have a lift. Works Great! Switchpath just ADDS Mufflers and an electronically controlled Valves to route exhaust gas either through exhausts, or STRAIGHT OUT the REAR.....

I noticed that Even when I drive in C, YES I drive in C sometimes on way to work when I want to just chill. But in COMFORT with Exhaust Closed, when you Get On It,,,,,,,,,,,,,you hear the Turbos from the under the hood much more.

Today I was driving home in S+, and when I am in S+, I Typically Always Open my Exhaust Valves with my Remote AWE Fob and get lots of POPS, LOUD POPS like Gun Sots and Explosions at times, not as much LOUD long successions of Burbles, but I get Burbles. Anyway, I was driving home on the freeway, but it had an open highway at times, so I was able to slow down and start from 2nd and 3rd. THIS TIME I CLOSED my Exhaust Valves, but left it in SPORTS +, and WOW, The SUCKING SOUND from Under the Hood was So LOUD. I for some reason never done that before. It made it FEEL FASTER, like it was more Responsive? Is this in my Mind, or does routing the exhaust through the mufflers in S+ give some sort of back pressure? It felt much more SMOOTH, but TORQUEY. Like I was in a more refined car, vs the OPEN Exhaust which sounds GREAT, but is more Violent and Open Sounding.

I HAD my DRAGY with me and found a great road to do some 1/8th mile runs, but it was rainy and wet, so I may try tomorrow. I MAY try a DRAGY Run with the Exhaust OPEN, THEN Closed to see if one gives any more performance than the other.

Just sharing and does this happen to YOU GUYS with the OEM Benz Performance Exhaust? I mean the Turbos I really don't hear with Exhaust OPEN in S+, BUT CLOSED was the LOUDEST I ever Heard and didn't even know it could sound like that? It was like a Rocket and WHOOSH and SUCKING SOUND! It also seemed my Tires did NOT SPIN as Much from a STOP, with FLAPS Closed in S+, but didn't do it enough to be sure.

Again, kind of a silly post, more of an observation, but if I had someone in the CAR I would definitely CLOSE the Valves for a little while and let them hear the More Refined, but aggressive WOOOOOOSHHHHHHH, sounded So Cool! I AM TUNED with Stage 2 so I have a little more HP/TQ being pushed out the back.

 

Closed exhaust valves would theoretically move the torque curve down lower due to lower flow characteristics, so the change in powerband might be noticeable. But in general, I've noticed in most of my modded cars that taking off the loud parts and putting stock stuff does make it "feel" quicker, but in actual numbers it doesn't help. Just a disconnect with what you hear and how you perceive it, in my opinion.

 

Thanks for your response. I don't think the car is necessarily faster, BUT, I NEVER Heard my Turbo Sound like that before, it was always there, just never chose that combo to drive aggressively in and it really surprised me.

 

disconnect the BOV recirculating lines to the intakes and you really hear your turbo's..with or without valves open

 

Yea that'll do it..

 

have you done that? does it make excessive turbo noises? i wouldnt mind some swoosh sound but dont want to start sounding like those tuner japanese cars.

 

yes...I was "forced" to as the ZAC intakes I have don't have that input. I have their RPA coming in the next few days...so, was all planned that way ;-) I don't find it excessive. Normal driving you will not recognize it only when hitting it to push the boost. I like the spooling and swoosh sound but its not really THAT loud. Noticeable, yes. I cant even hear it from outside, just with windows up and inside. Most noise still comes from exhaust (I always have ASR open) ....but don't trust my ears (my wife says they are broke) just disconnect and make sure to put a plug over the intake ports. 10second job and easily reversable.

 

Makes sense, dirt won't accumulate in now open tubes and cause issues? Whats the point of wasting 200$ on BOV since this mod is identical?

 

For normal use and most other cases no difference. I assume dirt can accumulate in the tubes but valve is closed and when it opens it blows any dust out. So, don't see how that can affect anything - same for all open vented BOV's (not just ours).
The OEM BOV is plastic and ECU controlled. Aftermarket s billet style and mechanical controlled and improves throttle response a little (tiny) bit (at least that is what is claimed). Its been said OEM plastic BOV's tend to leak and one guy here reported it melted (can search for the thread).....but changing the BOV is still borderline a preference thing (except maybe if you run crazy power).

 

I researched the BOV, as it's kind of cool when you hear it on videos, but I decided, it would get OLD fast, and if I do anything, I may get the new MW Intake that was recently released. Seems it adds quite a bit of sound and noticeable gains you can actually feel. NOT sure how that would affect WARRANTY and mine is under warranty until June 2021.

 

My ModalWorks intake sounds incredible with the valves closed, you can really hear the turbos sucking and the whoosh of diverter valves recirculating the air back into the intake. Highly recommend going WOT with the valves closed if you're a fan of hearing turbo intake sounds over the exhaust. With the exhaust open (especially with aftermarket DP's) it's much harder to hear the intake with the exhaust popping and banging away.

I would never install VTA adapters (last time I had a vent to atmosphere BOV was 15+ years ago on my single turbo 2JZ) - the ModalWorks intake that recirculates gives more than enough whoosh and sucking sounds! I have a brand new pair of mechanical Turbosmart Kompact recirculating valves that I plan to install to "upgrade" sometime soon over the plastic, electronically controlled diverter valves. Replacing OEM plastic diverter valves is usually the first mod I do on any turbocharged car when upping the boost over factory.

 

Alex, I want a MW Intake maybe one day. People really seem to like the MW Intake. Someone told me it's like a mini tune, and they feel it more in the higher rpm's? Do you feel any more LOW end OOOMPH with the Modal Works?