Me too, I doubt they increased the eccentric shaft, but I'm still not convinced that they can rev. to 13,000rpm without riability problems. All I know that RENESIS rotors are Stainless Steel, thus the weight saving. The R26B 4-rotor had them. Also, I'm aware that all of the 13G, 13J, R26B racing engines employed a 1 mm bigger eccentric shaft vs. production ones. I.e.: The production 20B can rev around 8400rpm to 9100rpm (can't remember & won't tell), while the 13G's bigger shaft were able to rev up to below 11000rpm, over the production 20B's.
But now a days, I'm sure Mazda racing development have been concentrating in producing more Torque... over Hp. Those high rev. number, are not needed (9500-11000rpm).... due to other factors like: restritors plates, riability & other impossing racing regulations...
But, I'm sure the RENESIS engine have gotten alot of the racing technologies to produce *250PS (It's been rumored over +290PS-320ps could easily be obtained with a remapped ECM (Mazda Speed?), exhaust & tuned header).