15G a good Idea? Any Experiences

I searched but only found one post. Anyone use 15G turbos before, becauseim thinking about getting one. I was told that they are capable up to 260hp. All I want is like 250hp until i rebuild. Thinking about boosting either 8 or 10 psi constant. Current engine B18A with 156k miles.

Please tell me what you think.

you wont get 250hp on 8-10psi out of a 15g

you start getting higher than 10-12 psi you might put that turbo out of its efficiency range and the IATs might get to high