OT: Mazda RX7 FC3S

[Mux213]

FB indeed is great with the 13B

But don't be put off by the SA's, 12A engines have great tuning potential! The only downside of the SA's is that many of them have rear drum brakes and that they're rusted.
But slam some mikumi's and a good flowing exhaust pipe on (forget what you've learned about piston engines and scavaging and shit, all don't matter with rotaries, simple header, big pipe, good muffler UP UP UP HP) and you'll run circles around FCs. Do a nice porting job on the intake and exhaust ports, you'll be leaving FDs in the dust (and stopping at every fuel station ).