[STONEY_M5]

I have a question which is really bothering me.. I bought the spearco/turbonetics intercooler, after the install i took it for a test drive and noticed that my boost gauge was reading only 9 psi peak as oppose to the 15psi peak i was running before the install. I know that you should expect some loss of pressure due to the bigger intercooler, but not such a big loss. power did fall off a bit but not much. Is this something to worry about or is it normal??? I upped the boost about 2psi and if felt a little bit more powerful than b4 which was expected... Somebody please help........