I was both surprised and pleased with the performance of the Wankel engines. We are evaluating them for possible application to a CL scale twin.
I have two, the original version from quite a few years back and also the present one.
The new version weighs around three ounces more and is of a different intake configuration, known as charge cooling. I researched this principle years ago for application on full-sized aircraft, finding a slight weight gain with no discernable improvement in performance.
The OS Wankels showed similar behavior. I tached them both with a 9 1/2-6 Master Airscrew plastic prop. The older version showed around 13,800 RPM, the newer one just a tad more.
As Ken pointed out, the plane effortlessly and with a bit more tailweight, it would have been better yet regarding maneuverability.
A huge issue as most of you know is vibration - there isn't any. As mentioned, the sound is unique but when holding the running plane, it feels like electric power.
I plan to try it in a larger stunt ship to see how it fares. Also how it turns a larger prop.
I'll post more as time permits.
Bob Z.