I'll let Spartn27 field any $$ q's, I'm just the guy that made a prototype. Lol
As for increased flow v. restrictions, your guess is as good as mine, but after all of the research, I basically came up with; "well, if it's good enough for a GT-R...it's good enough for my XSport." I realize they're different vehicles, but on paper the engines are actually pretty close to start (numbers anyway).