Originally Posted by V8Bait
All good words. I'd rep you if I could but apparently I need to spread around a little more first.
I have the "Internal Combustion Engine Fundamentals" by John Heywood who could be the other author from Sloan. He's the man. I picked up the book probably 10+ years ago on the advice of a bud that actually attended class with Heywood at MIT. Book is still relevant after many years and not exactly cheap anymore ($225 on amazon, yikes!).
I agree with re the airflow in the head as well. A great turbo can mask some of the issues, but 4 digit HP is not going to be easy without head work. I'd love to port one up myself and thought about picking up a used N54 head but I don't have an N54 car anymore nor ready access to a flowbench. "