hello basically there are many mods u can do to my car but what are the cheaest and best mods to put on for performance? basically i got a dark gray auto gst-t skyline. I have an apexi safc,stock ecu and turbo, 3 1/2 inch exhast with tip,dump pipe,front mount intercooler, pod filter,600 horse fuel pump i think!! what are the cheapest and to gain power and also what are the dear mods which will give power! are then any electronic mods i might need?what ecu should i get for price?and advantages! what things will i need is therer anythine i can do myself for the car for more power and speed? (sorry if i sound dumb but this is my first car and i dont know a hell of alot) oh yeah its a series 2. thankz for your help and time.