Not that easy, it's 10hp per properly supported psi in the turbo's efficiency range. A small stock turbo starts blowing hot air pretty quickly, and the rule assumes all the supporting mods are there.

What do you have, a standard sr20 swap- intake, front mount, turboback, untuned? Probably more like 200-210 whp on 10 pounds. Friend of mine did 220 on 14psi untuned with that same basic setup.