How is boost pressure not lost through the sound system resonator

[Birth25130]

Recently I found a rattling in my car which was related to the sound system resonator (u-shaped pipe that connects the intake pipe to the firewall / pollen filter).
I ended up removing the u-shaped pipe and blocking off the intake pipe with a silicone cap.
It looks like the system is supplying air to the cabin through the firewall and that the air is coming from the engine air intake between the intercooler and throttle body.

Looking at it I have no idea how the RCZ does not loose boost pressure through this pipe / into the cabin.

Does anyone know how boost is not being lost here?

 

[JvdBosch]

I’ve been wondering the same thing. I’ve also removed the final pipe and replaced the filter cover with one without the hole. I guess there must be a membrane inside the tubes, allowing the sound, but preventing leaks?

 

[Pedro]

Loss of boost pressure triggers the EML & will possibly put a car into limp mode the resonator was design not to have any effect on the forced air stream into the Turbo ?

 

[lfe]

My 156HP does not have that U-shaped pipe.

 

[Birth25130]

Ife, what does the cover for your cabin filter look like? This is a picture of mine poking out from the firewall cover. I capped it off with a silicone plug.

 

[JvdBosch]

I just purchased the part for non sound-system cars. That one does not have the hole. But capping off works just fine as well.

 

[lfe]

Ife, what does the cover for your cabin filter look like? This is a picture of mine poking out from the firewall cover. I capped it off with a silicone plug.

My car has a piece of fabric held in place with plastic rivets and no holes.

Removing the rivets reveals an elongated plastic cover, and inside is the cabin air filter.

I have no idea what that U-shaped tube does.

 

[JvdBosch]

The tube is part of the so-called sound system. It is designed to put some engine noise in the cabin, for a sporty feel to the car. I removed mine and I still get enough drone from the engine for my taste…

 

[lfe]

The tube is part of the so-called sound system. It is designed to put some engine noise in the cabin, for a sporty feel to the car. I removed mine and I still get enough drone from the engine for my taste…

I don't want that either.
The quieter the better, and I find my RCZ to be quite quiet, a pleasure on long drives.
Noise also tires you out.