OK this will be the third time I have made a thread and not gotten a good answer some I'm gonna try one more time.

This is a picture of my boost gauge at WOT:



Anyone know what could be causing this. MAP sensor?

Here some info though:
When I bought the car, the supercharger was not connected. There was an idler pulley that was shredded and the S/C belt was just sitting there, for God knows how long... So when we put the belt back on it felt slow still, and over time (after the PCM put some more timing in) it got a little faster, but still doesn't quite feel as strong as my old black GTP. (I could be wrong though)

Any help would be appreciated guys.