Hello gang,
I am new to the RX7 world on only one year into it.
My son and I have lucked into a 82 RX7 last year that has lived most of it's life (our understanding) as a race car I think I heard SCC so something like that. It is now a bit old and tired and we have run it in one 24 Hour of Lemons race at Sonoma Raceway and had loads of fun. We a getting ready for another race at Sonoma in 2 weeks and were doing the brakes and rotors and noticed that the right site brake vent backing plate was missing the attachment duct.
We do know that the front axle has been 100% or partially upgraded to 1985 parts. But in looking into the parts list for a 1985 RX7 brake vents were not stock, So i am posting some photos of what we have on the left side hoping someone will know what these are from.

 

Wow those are neat. Definitely not stock. I've seen people cut holes in the stock dust shields and run ducting like that, but that looks fabbed instead of homemade. Can't help ya (I'm not a racer) but cool to see.

 

Mazda competition used to sell a couple different ones,

 

Yep, looks fabricated and possibly aftermarket, but with the duct all kinked up it's probably not routing much air, anyway. Plus, if the duct on the other side is torn, you're probably not getting even airflow on each front rotor so one side will get hotter - and wear differently - than the other causing weird braking effects. I'd probably remove the ducts and see if you can find stock backing plates. Even those had a small flap that extended into the underbody airflow to catch some air and push it through the center of the vented rotors. The 84-85 (S3) front air dam even had slots molded into the lower valance on each side that matched up to metal directors (*it would be a stretch to call them ducts) to suppmy fresh cooling air.