Whenever you want to go faster than 15-16# boost will get ya--you need more boost, timing & fuel. Alky injection is a good way to achieve that higher boost, more power, go faster, etc... Of course your fuel delivery system needs be capable of furnishing enuf fuel to get there...
Without knowing your typical fuel octane available there (most here build upon 93 octane), it's hard to say max boost you could therefore safely run...
I would think a stock turbo would safely run around 20# boost, with alky, and easily put you around mid-12's. Of course, you also need an adjustable waste gate controller to get there, etc,etc,etc...
Baby steps, baby steps...