Unfortunately, I can only reference Alpine Supercharger as a prior example of forced induction on these engines and it made 60-70 HP on 5-6 psi of boost. That is about 12hp/psi of boost.
Turbos are more efficient (especially when combined with intercoolers) and I will have much better engine management. So it isn't unreasonable to expect 15hp/psi from a well designed and tuned turbo system.
But... I hate "bench racing", so I will not put too much weight on this until it goes onto rollers
For the record I want to add this dyno thread, so that I can compare to it later, after I get my own numbers:
http://vehicross.info/forums/showpos...9&postcount=11