bnr32skyline

i just started doing a convertion from a rb20det to a rb26dett im new to the jap stuff so my question is about the induction on the 2 turbos there is pipeing going from the filter box to the inlet of the turbo but just infront of that theres 2 pipes that run off that into a my guess expantion box this all connects across the radiator support what is this thing for?? and can i get rid of it and just block the pipes off????