Stock R34 Airbox Q

[Danox]

I just picked up what i understand to be a complete R34 GTR airbox for my car. Currently I have cone filters. It's pictured assembled here with the scoop snorkel removed for clarity.

I'm a bit confused about something -- obviously, the top air input comes from the air snorkel, but the one on the right, which is teardrop shaped, seems to fit into a matching teardrop hole in the right side of my engine bay. It's listed by Nissan as an air duct. However, this one is closed off -- as shown here. (I've since removed the foam and cleaned it up in the 2nd pic, and will reapply a foam layer that isn't falling apart.

I don't understand why the airbox even has a intake hole on the side if this is supposed to be closed off. Do I have the wrong part or something? It fits so perfectly, but it doesn't even seem like a duct to me, it has no airflow.

What am I not seeing or understanding about how this works? Why is it there if it's closed?

[NZ-GTT]

I too have the same question about the side duct  on the R34 & R33 gtr air box that is blocked off, Do People remove this cap or is there enough flow from the snorkel to support 350rwkw? I want to get rid of my pod filters and install an oem air box.