Any ideas?

[Justin14100]

A G60 throttle is totally different, its got two butterflies in it much like a polo GT, and I think the primary throttle is actually smaller than the G40 one.

[Justin14100]

Also there wouldn't be any point in getting anything bigger than 57mm as that is the size of the engines intake pipework

[Jezza-7]

Indeed.

Oh well i never knew that.

[hayesey]

depends if you are using the standard intake pipework!  Which I'd have thought not if you're modifying to the point where the throttle body needs to be bigger than 51mm.

There's also the possibility that if using after-market management you can get better throttle control using dual butterflies.  Andy does the same on his although I think he's using parts from an NZ engine.