Hey, I have a question that has been puzzling me for a while now. The last time I dynoed my car I noticed that I start steadily losing boost after 5500 RPM. At redline, my MAP sensor reads 3.0 psi of boost! Is this normal? If not what could be wrong?

I e-mailed Jackson Racing about it and they didn't seem overly concerned. They told me that my s/c belt might be loose or that my engine is just really efficient in the high RPM's. Can anyone explain to me the reasoning behind this? Is it because of overlap?

Thanks.