first do yourself a search..then you might find some of the following useful mods
* full exhuast (dump pipe, front pipe, high flow cat, catback)
* a bigger intercooler
* add more boost, safely 10 -12 psi
* improve your intake with a panel or pod filter (enclosed)
* some form of engine management (haltech, power fc, ems) or piggyback system (SAFC, emanage)
this should get you with some nice power
Then make sure u can put this power to the ground effectively with a good suspension setup, a stronger clutch and tyres
if u want more power, ull need to change your turbo, fuel pump, injectors, and AFM is ur not using engine management with a map sensor. but this will require more than 5 k