i don't remember the front & not sure about the rear, but if i remember right the rear is 63.
having say that, does the new GT3 wheel has the same offset as 18" sport techno. if so, with 17mm specer the GT3 wheel should work perfectly on Turbo right?

 

front = 40, rear = 63 mm's for 8.5Jx18 H2 and 11Jx18 H2 wheels respectively. Specs from the manual page 184.