I can't lock the wheels on my S8. I can't even trigger the ABS on dry tarmac.
This is what I mean about the 18z calipers btw:
The caliper lugs and the upright lugs both occupy the same point in spacetime. There's nowhere to create a bracket.
However, this is the first time I've tried with a 345mm S8 disc, and its actually pretty close. I am going to try some C5 A6 hub flanges later which sit 6mm further inboard than the D2 ones, and it might just work. I feel that these calipers would be a worthwhile upgrade from the stock Brembos, even on the same size disc as they tend to work properly for longer, are lighter, and should give more even pad contact. I'm not sure they would be better than the 360mm D3 setup though, even with the associated weight penalty. I'd probably have to try both back to back.