The benefits of going NA on a rotary is that you will be taking advantage of its high rpm capability. It is generally accepted that the higher your revs, the more power you make. This can be seen in bike engines and obviously, F1 engines. Piston engines are limited by something called mean piston speed which is a function of stroke length, hence short stroke engines are able to rev higher. The rotary does not have this limit. In addition to that, the eccentric shaft rpm is geared to run three times faster than the reciprocation of the rotors ie; at 9000rpm, the rotors are only reciprocating at 3000 rpm. Thats alot less stressful than the piston bangers brigade.
The next factor in making power from NA rotaries are the ports. As these things have got no valvetrain, intake and exhaust timing are determined only by where the ports open and close. The term porting in rotary tuning basically moves the opening point of the intake and closing point of the exhaust to produce more overlap, equivalent to valve overlap with piston bangers. This is decided upon by the target rpm you want to make power at ie; 10 000rpm for a sprint track racecar. I believe rotaries can go higher but one of the biggest limiting factor is the eccentric shaft, which will inevitably flex at these rpm figures. Once that happens, bearing journals get misaligned, friction increases, lubrication is compromised and you'd be on your way to total engine meltdown not long after. Anyway, digressing from the fact....
Reviewing what has been written above, it can be seen that the rotary is pretty inflexible when it comes to power generation. High overlap engines will make huge power but you can forget about idling. And street car use. Unless you enjoy riding a bucking bronco while in the lower revs. I remember when I was working at Sepang during SuperGT, Amemiya's car pretty much bucked its way to the pitlane speed delimiter line. Only when the driver shut off the speed limiter and floored it did everything become smooth.
On to the question of fuel consumption. As the engine will be so inefficient at low revs, you're more or less chucking out litres and litres of unburnt fuel as pretty fireballs out your exhaust pipe. However, when it comes on song at whatever rpm the port timings was optimised for, they're very efficient. Evidence of this is the famous Le Mans winner. The 787b sipped fuel when it was ran at close to its 9000 odd rpm limit compared to the other cars. The low 9000'ish rpm was used due to reliability concerns. It still made 600 odd horsepower though... In summary, the NA rotary is very fuel efficient... only when you keep in its powerband: anything above 6000 or 7000 rpm, I guess.
As for individual throttle bodies, it is more to do with throttle response. NA engines are renowned to be linear and ultra-responsive. ITB's are just one of the ways to make that happen through efficient and equal flow of air into cylinders/ports/Satan's arse/whatever. From a well designed airbox, obviously.
I've no idea if its been done in Malaysia, but the Australians who're hardcore Wankelians do drive bridgeported and peri ported 2 and 3 rotors on the streets. Possibly daily :stupid:. Some even build their own 4 rotors. If you've got time, look up 'gtorx7' on rx7club.com. The last I trawled there, he was running a 20b NA engine in his FD. With something called auxiliary peri ports. He also sells kits that enables a 20b to be fitted to your FD while still retaining the stock standard subframe with no welding.
This is my 0.02 sen. I don't own a rotary, nor do I drive a car. If I've gotten anything carelessly wrong, I hope the sifus here will point me in the correct direction to do more research.
Thanks for reading =)
Cheers.
