Boy the stock intake (even the filters) really flow well from the data I'm seeing. Our filters are actually larger in dimension than what Nissan puts in the GT-R. The paper media in the OEM filter also kinda looks like the Nismo high flow paper filters.
AFE has data on their site that a stock filter flows 355 CFM @ 1.5" H2O. And we have 2. There is no restriction there whatsoever. Incidentally K&N's flow data on their drop-in for this car is also 355 CFM lol.