Guys I hope you can help me,I have a set of HRE P43 for Turbo and I want to use them now in a C2S cabrio.

1-I know a very good shop that modifies offsets,how much I have to reduce?
2-What size of rear wheels do I need?

Thanks

 

The front offsets are usually 57mm, but you can go to 50mm if you want the wheels further out. Rears are 67mm, but you can go to around 50 mm if you want the wheels further out.

 

So the fronts are the same?
The rear turbo HRE wheels will go out for sure since they are 12"

 

Yes the fronts don't change. Only the rear wheels have lower offsets on wide body 997 cars.
BTW, factory rear Turbo wheels have less offset than narrow body rear wheels, but some people still use them on NB cars as it gives their car a more aggressive look. So you may not need to have them modified, unless the rear HRE's have even less offset than the factory turbos. Try them first before having them modified (for a larger offset).

 

Yes good recommendation,I think it is necessary to reduce 5mm and also check if the 12" rear wheels will fit inside the fender with out touching the shock,arms etc.