It is a 2" pipe and I don't know what comes from the bottom and where it is aimed at near the rotor. I did not even remember to look at the brake ducts when Randy changed my brake pads during Mancation (I was paying close attention to handing beers to Randy and myself
) and orbit serviced the car when I came back and told me all is OK.
The ducting is probably not needed with the PFC stuff, but I don't think it can hurt either.
The PFC stuff has such a great brake feel that the brakes have become such a non issue that I have to remember to look at the pads or anything else. The Pagids felt so crappy I was looiking at the pads every other session after 4 days on track. :-)