Op did you upgrade the throttle body and port match the the rbc? And you have not tuned it? No wonder its running like shit. 8kw increase is not to bad for just rbc and injen, considering it hasn't even been tuned yet. Just leave it stock until you get your opens, then decide if you wan't to turbo the car or sell it and move onto something more performance oriented.

You'd be looking at big bucks for fd2r k20 plus bolt ons and tune.
No i didnt upgrage the throttle body or port match the RBC although i was told that it was very small and that i should look into getting a throttle body from a Acura TSX 07/08 for improvements. Aparently its not that expensive to source, about 4.5 k for the k20z4 or the k20a and most affordable choice is the k24's for 2 k and to drop either engine in for $1000 from my tunner

Big big bucks for any engine upgrade into your very oh so tight engine bay. Expect $10k or so for the block + install + tune
Hope fully i can get it done within a decent price range.

Correct me if i am wrong, i will be getting qutoes for these engines that i believe are compatible with my car.

-K20A FD2R
-K20z3 FG2
-K20z4 FN2
-K24z3 2008+Euro
-K24a3 2003+Euro