Using logic it should be both.
Cut the fuel with cutting ignition and you have an over lean situation. (not good)
Cut the ingition without cutting the fuel and you have a over rich situation (not as bad but still not good)
Cut both and you have a loss of power. (good for the engine, bad for the race)
But if you are still shooting NO2 you would have a problem...
Perhaps the better question would be; How can I tie the rev limmiting feature into my NO2 application?
Now that would be nice. :wink: