brap is the sound a rotary engine makes when idling. it sounds like 'BrapBrapBrapBrapBrapBrapBrapBrap'
Never heard a rotary brapping like that. Could be because the only rotary I've ever heard on idle was a stock RX-8. Or was it an RX-7? You see, some time ago either...
Wait... they make a 12-rotor Wankel? How on earth does that work? How big is the thing? I've seen pics of a 4-rotor and a 2-rotor and they're pretty big... at least it looks like they are, maybe they look bigger in photos than they really are; they were pretty much in the middle of an empty room in the photos.
I think it was 3 of the 4 rotors in some configuration I am unsure what config that was but it was in a video and it produced something like 1400bhp...
There has been a bike with Wankel too, so rotary engine is not only for four wheels: http://silodrome.com/norton-classic-rotary/