[JonA]

You can substitute the throttle body from an older 5 cylinder Audi. The openings are noticable larger but I dont have any exact numbers. It will bolt right in with only minor modifications, one or two tappings to accomodate mounting the switches and you have to use your original butterfly shafts so that the throttle cable stuff can reattach without modification. I believe Obin made this modification some time ago, do a search.
I got the throttle body in the boneyard for $10.00!!!
I never got this done so cannot comment on how much power increase it provides. I suspect that without other intake mods it will not do much.
Good luck,
Jon