Well its in the design and coating both. The plasma coating is a thermal-barrier coating developed by NASA for rotary engines, ceramic coatings resulting in the ability to withstand surface temperatures beyond the capability of conventional
metals or hydrocarbon lubricants, and further protects the metal from the hot side also.
The PS200 plasma-applied coating, developed at the NASA Lewis Research Center as an unlubricated wear coating consisting of chromium carbide with silver, and a fluoride eutectic for high temperature lubricity. Its applied over a thermal barrier coating in a plasma applied coating process and can permit engine operation without external lubrication. Runs much cooler and aids in the combustion process also to get better fuel economy, power output and much cleaner and greener emissions.
They also have a specially designed porting system for a charged cooling system that removes heat and makes it much more efficient than other rotary designs, see
http://www.nasatech.com/Spinoff/spinoff2001/t2.html for a NASA article on Freedoms version of the OMC rotary
http://www.freedom-motors.com/ (he has the rights to all non aircraft engine versions and works with Rotamax in the engines development.) A 10 HP rotary that fits in the palm of your hand, 160 HP that fits in a 5 gal paint bucket and you can put the lid on. He is Mr. Moller who makes the Sky car (see at
http://www.moller.com/skyc.htm ) and they both use the same basic engine and coatings developed by NASA and the old OMC Corp.
Also if you listen to the newscast at
http://www.mefeedia.com/entry/3204436/ where ANN's Paul Plack talks with Eric Barger, president of RotaMax Rotary Engines, it is explained pretty well, and when they were challenged by a septic saying “What are you doing different than other rotary engines with the charge-cooled?” , their design engineer replied with
Charge-Cooling 101: Increasing load causes us (via human intervention or governor throttle response), to increase incoming air fuel which is drawn through the side of the rotor in a way that decreases the heat in the rotor (and E-shaft), while preheating the incoming air fuel mix, which results in the water jacket of our engine registering a lower temperature under heavier load and higher rpm settings. I know it sounds counter-intuitive, but its true. The heat is extracted from the rotor into the incoming air/fuel mix, then used in the combustion chamber and is sent out the exhaust.
Controlling ports, controlling fuel delivery, and controlling emissions, all are controlled by MotoTron electronics. That is what is different about our charge cooling. RotaMax routes the flow of the incoming air/fuel mix through the side of the E-Shaft and rotor (yes our E-Shaft and rotor both has holes, Mazda’s are solid) to extract heat from the rotor
before reintroducing this newly preheated and turbulent air fuel stream to the combustion chamber. Mazda uses an oil splash to remove heat and that is nowhere near as efficient as this process.
Charge Cooling is a simpler, more efficient approach, but what is different is we’re controlling our charge cooling by the ECU as described above. Here is just one indication that Charge Cooling is more efficient than oil cooling of the rotor: Our engine liquid jacket is only around part of our engine center housing (from the spark to the exhaust) while the Mazda requires a water jacket all the way around the engine. His challenge would be true, if like a two stroke, our incoming air fuel only went directly into the combustion chamber. but It doesn't.
He’s right in thinking that the heat has to go somewhere, It does: out the exhaust. But, since he doesn't understand our intake runner’s path, he doesn't understand how the heat can leave the rotor in this convoluted, but important way. He just has not stood at our dyno and seen us add heavy load and throttle to an operating engine, and watch the water jacket temperature go down. The benefit of the ported body and the NASA coating work together to perform miracles. The smaller cooling system, radiator and no crankcase, filter or oil (the injector system uses much less oil) also reduce weight further.
This outfit (
http://www.powersportaviation.com/Home/Testing/Testing.htm ) has a good product line also, with PSRU's, (see at
http://www.powersportaviation.com/Home/Reduction drive/Reduction drive.htm ) exhaust systems etc, and are for ALL rotaries including Mazda's. Really cool is the 20 pound no Governor or controls NASA designed prop, called the QCS (see it at the NASA site at
http://sbir.gsfc.nasa.gov/SBIR/successes/ss/3-085text.html ) that Power Sport Aviation is also doing. Super efficient, no pilot burden at all, no controls, full self adjusted with no moving parts. Its high output design (based on the new turbine prop technologies) carbon fiber construction is a quarter the weight of its Constant speed counterpart, whose prop controls and the oil to drive it makes it 60 lbs heaver and it is still not as fast or powerful in thrust or output) So much new stuff coming on-line, way cool.