For a start i dont know if u got it but i would get a filter ,either pod or in box k&n.A dyno will help your car run its optimum for the set up u have .Some dyno places recon they can get another 10=15psi just by dyno tune ..With the standard ecu there isnt tooo much to change.I would get it dyno to give u a starting figure before any mods.Also my r33 ran better at 10psi than it does on 12 psi,so things like this u can set up on a dyno.