[bhazard]

Seeing as a turbo is powered by your engines waste, rather than off the crank itself, I dont think they draw any power from the engine. The power band depends on the turbo. A smaller turbo will spool quicker, if not off idle, and will make power right away, but will choke out in the upper rpms where the turbo cant flow enough air to keep up with the engines needs. Or you have have a big turbo that takes its time to spool up and pulls as far as your engine will take it.

I *dont* really see a turbo being "strong" enough to turn the accessories. Theyre made to move something "light" like air. Plus the tension from the belt would probably wipe out the bearings or bend the shaft right away.