I don't know if the nitrogen is involved that much, in this principle. Nitrogen is important only as flame retardant to reduce the combustion speed second my thoughts.
I believe that he had constant pressure from his cell so he just mixed the gas switching with a butterfly valve between air and exhaust to control acceleration. Air for maximum acceleration and exhaust for idling. Obviously he might have limited also the resonant action to a certain degree in somehow as to have a increase in gas production in relation to rpm. I'm still working on that to find some more answers.
I'm happy that you enjoyed!
Stevie I was reading this
http://en.wikipedia.org/wiki/Magnetic_field and found that charged particles have a magnetic field. Ions... Ionized gas...
Probably we need to ionize the gas before it pass thru the tube. Or maybe only the magnets will do the job. I'm happy to say that I don't know yet.
Lets find out!