wasnt to sure on the throttle body, so i managed to dig this info up:-
There are two main areas to bare in mind about swapping throttle bodies, the overall area of the two throttle plates and the relative sizes of the primary and secondary throttles.
If you feel that your engine could make gains from increased airflow due to other mods (air filter, cams etc) then you may see a gain from a larger TB but remember why would VW let your car leave the factory with a TB that strangled it top end, they wouldn?t.
Secondly the ratio of size between the primary and secondary throttles is designed to match engine characteristics. So simply swapping TB?s may make your car feel like it pulls harder top end but it may be that what you?ve actually done is stuffed the light throttle response.
Here?s a very rough ?rule of thumb? for you, If you have an engine with loads of torque you may be better off with a TB that has a larger primary throttle plate, if you have a very top endy engine you are probably better off with a small primary and much larger secondary.