Quite an old thread, but re-found it while searching for another old thread earlier today.
If you have a few spare hours, it is well worth a thorough read.
Original thread here:
http://forums.evolutionm.net/evo-dyno-tuning-results/447351-highest-hp-4g63-engine-2007-a.html
Semi-summary thread here:
http://forums.bimmerforums.com/forum/showthread.php?1575817-An-Example-of-Truly-Impressive-Turbo-Engineering
It really is amazing what can be achieved with a limitless budget.