Boost gauge readings on 06 wot

[Gil Moncrief]

I have a stock 06 6speed 4wd. while blowing out the carbon in 6th gear with the throttle wide open, I observed the boost gauge to go briefly up to 30 psi and instantly drop to 25 psi. This happens every time. Is this correct? Do I have a leak? Responses will be greatly appreciated.

 

[DJennings]

It's correct. The electronic wastegate opens at around 30psi to keep boost from getting too high (based on DC's standards). It will drop off fairly quick before the wastgate closes. It's normal for a stock motor.