HP is going to vary a lot, depending on weight, suspension, track, altitude, etc.
As a nitrous car, I ran numerous 10.0's: stock bottom end, heads, cam, intake, weight: 3450; poor track; usually 3500DA; hp approx: 600. I have seen numerous 2800lb cars make 9's with a lot less HP.
Your friend is full of it, if he thinks he'll ever make 9's. A buddy of mine that races a 2300lb Honda with 800+HP is knocking on the door of 9's. Tell your friend to save his money or better yet, give it to me
David