I don't know if its been done before, but the rabbit pads have about twice the friction surface then a G60 pad.
Increasing the friction surface on your pads will change ABSOLUTELY NOTHING exept that they will last longer than your stock G60 pads. Performance wise it will change nothing. Basically the brake pressure will be divided over a larger surface area. When you calculate braking force, the surface area of the pad has no impact on braking.
To calculate braking force you multiply :
Normal force X coefficient of friction X radius of your disc
Normal force is the force your brake calipers exert on your discs.
Coefficient of friction is the friction between your brake pads and disc.
Radius of tour disc is the diameter divided by 2.
what you need to do:
Buy pads with a higher coefficient of friction (i.e. semi-metallic aftermarket brake pads.)
Use larger rotors
Increase brake pressure (i.e. larger diameter master cylinder or more power brake assist)
It's a really nice project you've got there, i've always liked MK2 Jetta's and Golf's. I saw one today with a VR6 engine. Damn it sounded good.
But i'd rather have your 1.8T engine though....
REP