For all those that read Hot Rod faithfully, this is old news. Two of the best tech articles produced about turbos, focusing on the T3 and T4 lines, are online now.

Part 1: turbo selection - A/R ratios, trim, housings, center sections
http://www.hotrod.com/techarticles/e...13_0312_turbo/

Part 2: putting it all together - intercooler, pistons, CR, piping, oiling, wastegates
http://www.hotrod.com/techarticles/e...urb/index.html

Good articles, good details, good pictures.