Firstlly Id run a search as this topic is one of the most common topics covered here at SAU...
Plus id do the search in the forced induction part of the forum as the max psi levels here in QLD are the same as everywhere else...
That aside,
I ran 14psi on a stock turbo but this was with everything else in place and a perfect tune...
I would not suggest it on a stock ecu tho...