a stock bottom end's limit is not dependant on psi. 10psi on a LARGE turbo pushes ALOT more air than 10psi on a small turbo even tho the air is pressurized the same, there is much more of it from the larger turbo.

therefore you can't judge solely on psi, you also need to include turbo size and then continue to fuel both management and delivery.

as stated above, tuning is key! a good tune will take you very far on a stock d motor. good rule of thumb is 200whp but people push that number higher and higher all the time

goodluck
-Luke