True, the Wankel was invented by a German, but made usable by the Hiroshima-Based Mazda in the 1960's with the original 10A used first I believe in the Cosmo. The design was actually licensed from NSU, and NSU used it in the RO80. In fact, if you look at the top of the rotor casing, you will see stamped in it "Licensed from NSU", despite the fact that NSU was absorbed by VW around 1977. ( I think the VW Dasher was actually a rebadged NSU. It was sold as the K70 in Europe). In fact it was warranty issues with the RO80 which weakened the company badly enough that they were taken over. I know that a motorcycle manufacturer of the 1960's also used a Wankel. I want to say it was Norton, but I am not 100% sure.
With the 13B-T what engine management are you using? I ask because the stock engine management is the main problem with the FD turbo cars as it is too easy to run it lean and kill the apex seals.