Without boost controller, stock as a rock car?? if so its around 7-8 psi, if you want to know much boost is it capable of i wouldn't go over 13psi, i've read that the exhuast wheel, being made from ceramic , will denonate from anything over 13psi and up.
S2 R33 you get what they call R&R rich and retard, at about 10psi basically the stock computer reads the extra boost as excessive air flow and doesn't understand whats going on so to protect the motor it richens the AF and retards the timing, but then again some people don't get it and run upto 12psi.
If you have a PFC you won't get it.