I have a friend that has a GTP. He asked about his boost gage. During hard acceleration or WOT, the digital (factory) bar gage seems to blink forward and backward as the car speeds up. The gage is increasing across (left to right). It just looks like it is losing and gaining as it increases. I guess what I would like to know- Is this normal (are other cars doing this). How much boost does a factory supercharger have or can produce.