Thought the vr6 only weighed 140kg without the gearbox, didn't think the 1.8T weighed much less, prob close to similar weight by the time you add the turbo on and the pipework? If anything a twin turbo'd vr6 would be ideal
Getting lighter components like alloys, such as "SSR Competition-H", then try and replace any external panels with lighter ones. Getting lighter battery as well, such as braile batteries. Uprate bushes like dogbone, this will increase cabin vibrations but reduce wheel hop. Smooth airbox out or induction kit. Full catback exhaust system with 2.5", upgrade camshafts to like 264degrees, this will prob give you the biggest bang for your buck on a N/A car