I'm sure I recall seeing larger diameter FD brake rotors are a straight swap to FC's (with 5 lug/4piston brake suspensions), and just require an adapter plate to relocate the caliper - anyone know if such a thing is sold commercially? I looked at Racing Beat, MazdaTrix, RX7.com, and a couple other sites and didn't see anything. Google and the RX7club search engine both gave a pile of useless search results.

I realize this might be better asked in the 2nd gen forum, but I'm pretty sure I recall someone here north of the Medicine line had either made their own adapters or otherwise mentioned the idea.

 

I know for the fronts you can use FC rotors and FD calipers without an adapter - I have this setup, but the rears require the adapter.
Or are you referring to the front brakes?

For the rears:
Super Now FD Brake Rotor Caliper Bracket Set FC3S

 

Rear setup on Chuckie's link is 112 CDN.

 

No, like pretty much all FC's, I already have too much rear brake bias, which I've tried for years to deal with by using more aggressive pads at the front. I can't put in an adjustable proportioning valve in my class, but I can do a big brake kit. The front calipers and pads are the same between FDs and FCs with the four pot brakes (GXL, GTUs/Sport, Turbos), but the FD has a larger diameter rotor, effectively delivering more leverage and so more brake for the front. My understanding is FD rotors are a swap on, and I don't want or need a lot more brake, just trying to balance the front/rear brake balance by upping the stopping power at the front. Maybe I'm wrong about the FD front rotors even being a swap on?

 

Oh I see what you mean now. I've not heard of this swap before myself.
Have you seen the EVO IX Brembo conversion, though? Andoru has it done on his Time Attack FC and it's almost a direct swap.
https://www.rx7club.com/2nd-gen-arch...pgrade-719567/

 

I was looking into this a while ago and even the Japanese companies seem to only offer the rear upgrade (Supernow, Knightsports, etc) consisting of a bracket to fit rear FD rotors. I've heard of guys on here supposedly doing it themselves by making their own bracket but haven't seen it in person myself. Eventually I was thinking of finding an FD brake disc (from scrapper or local FD throwing out a toast one) and just mocking it up to get a good look at what you'd be in for. Could be as simple as a flat bracket, but I suspect it's offset otherwise why isn't it a readily available upgrade? For me it would only be worth it at that point with some 2 piece disks to cut down the weight but the whole thing isn't that high on the priority list right now.