OK all the average Sea Level atmospheric Pressure is 14.7PSI so the 2.0 focus standard comes with 130BHP so running a focus at 10PSI with a turbo, the achievable BHP would be this :-

(130 / 14.7) x (14.7 + 10) = 218BHP~

This would be the expected BHP figure, not taking into account any other mods such as exhaust, filter, injectors and so on, so i would say add about 5-10% and you would have your estimated BHP figure

What do you guys think?

What do you want to know exactly? If it's possible to run 10 PSI on a stock engine..?

Without changing the injectors and MAF, I don't think so. Look here (http://www.focusfanatics.com/forum/showthread.php?s=&threadid=20982&highlight=tom+stage+turbo) for a kit on "stock" engine.

I'm saying with all the required parts to run 10PSI would that theory equate the expected BHP?