Stage 1 is just a chip which could take them up to 270bhp

Stage 2 is a chip green injectors 3 bar map sensor and i think the turbo actuator has a longer rod on it to get mote boost. Induction kit stainless exhaust.This could take you to 305 bhp (like mine was)

Stage 3 is the same as above,but with a bigger intercooler.Or differnet injectors.

Please correct me if im wrong people.