mate get some sort of fuel cut defender & compensation device, something cheap and oldschool (ie rebic lc
) and up the boost to like a bar and just go nuts.. worked for me in my 1g, an ull have a heap of response with that full 3 inch, ive only got a catback!! 1gs are particularly pokey at that sort of boost, trust me ull beat 180sx's & it shouldnt cost u too much. And i wouldnt suggest doin an engine swap, i looked into it and its always more expensive and painful than u think... just have a good look around till you can find urself a good quality second hand turbo kit, (trust me there out there and u can get em fairly cheap), and wack that on, those little twins dont really hold boost very well. Get some tunable management, give it a bit of boost and ur away!! (obviously slightly simplified but u get the jist).