RE: effects of nitro on ignition conversion
Nitro will give an engine more power and better throttle transition on an ignition engine just as it does on a glow engine.
I would also say that when going to a no nitro mix that you should retime the engine to find the optimum setting without the nitro. Nitro burns slowly, and you might find you need to retard the igntion a bit without it.
AV8TOR