The only thing I can think of off the top of my head is something we use on 3000GT's and DSM's. There are several different companies that make a MAF translator....there's MAF-T and I think one called ARC2 and some others. Not sure if there's something out there like that for the Miata.
Sorry to bring back such an old thread, but I have a question about swapping the RX-7 MAF sensor onto a 1991 Miata with the 1.6. Would this give me any gains? And if so what is involved in getting it to fit/work correctly? Any help would be appreciated.