Cheers. Can you give me more details on this achievement. I thought the CTS-V calipers were the same as Brembo's in size and function?
Yes they are same but you are going from 330ish to 355mm and two piston to four. Doesn't matter if fitted to another model variant, according to the technicality of the law (like I mentioned is only a technicality), you don't need full-on testing but do need approval.
I put four pots big disk on rears so there is no such grey area in the rules.
Assuming the disc hats have a greater off-set from mounting face to the pad contact face (effectively moving the caliper inboard) then the mounting face for the caliper would also have to move inboard. Am I getting close?
No cold, cold... longer studs and adding material to disk hat - 15mm rear and 20mm front.
Think like having spacers,
which are not subject to approval, this is spacing material fixed and integral to disk hat, not separate item between disk hat and wheel.