just finished installing a BC "Blitz" on my STI with stock turbo.
the boost will holed on 15psi and on 18psi. but when i go for more -23psi- it hits 23 and then gos down to 18psi.

the strange thing is that it stays at 23psi for 2 or more second, but while the RPM gos up the Boost gos down !!!


any idea on this.

 

What age/model is your car? Also what modifications does it have?

Sounds to me like your turbo isnt capable of holding 23psi and all you are seeing is overboost until the boost controller kicks in. I woulnt run 23psi on a standard car, in fact i dont think i've seen many people on here running a scoob that high....