dear mr. imranian.what u can do is very simple.first of all headers intake and exhaust.than head port and polish,clutch etc.but still u wont be able to beat a good gtti with orginal engine.to beat that car u will need either turbo or nitrous oxide so best of luck.
and by the way safeer ustaaz knows how to make 4afes fast in fact very very fast so why the need to ask around.go straight to his workshop which u know very well.