I have a type r, what diameter are the disks, 294mm??? And how big a disk can you put in before the 4 pot caliper refuses to work with it?

 

Assuming you already have the four pots then the disc size is 294mm, you can't fit bigger discs without using a kit designed to allow the fitting of a bigger disc, like the Godspeed 335 kit for example, thats about £600, but includes new discs, pads, and what you need to fit them!

Ron.