Don't forget that it was a Wankel-powered car that won Mazda Le Mans. Was it 1993?1994? Can't remember. IIRC it was a 4-rotor engine in the 787B. Very effective. SO effective it was banned the next year
In a 4-stroke, a cylinder has 1 power stroke in 2 revolutions. In a Wankel engine, a rotor produces 3 power strokes in a revolution. Therefore they have a 3:1 reduction mechanism to reduce this to 1 power stroke per revolution. This is why a 2-rotor Mazda 13B has a power signature like a 4-cylinder engine.
I think the 787B engine maxed out at around 13000rpm, meaning an internal speed of 4500rpm.
Getting really technical, maybe (I know it'll never happen) the FIA should regulate engines stating "not more than x power strokes per revolution" and "not more than y volumetric displacement per revolution" and hence we could work out a turbine/wankel/piston/stirling/whatever engine equivalence formula.
For Mazda/wankel fans, check out
http://www.pettitracing.com
They stuff 20B engines (2000cc, 3 rotors) into the RX-7 (normally running the 13B, 1.3l, 2 rotors). Sweet