"There was supposed to be an earth-shattering kaboom!" (extra points if you can identify who said that )
Nitrous oxide is an oxidizer. By weight, it contains 33% oxygen. When heated, it releases this oxygen for usage. Thus, it can add an insane amount of power when released into the intake of an internal combustion engine along with extra fuel.
Mixing these two gases in a tank would be a very bad idea. What could happen, is if it ever backfired, the fire could go back up the line and explode the entire tank. This wouldn't be your ordinary garden-variety explosion either. They'd be picking you up with a stick and a spoon...
Nitrous use with hydrogen would be feasible, but they would definately have to be kept in separate tanks. Preferably separated by a distance.
It's an interesting idea for a race motor though. The high compression hydrogen allows with the addition of nitrous should make an tremendous amount of power.
I saw a farmer in his late 70's interviewed on the news in the late 80's, he has his house on solar power, he had batteries in a section of his barn for storing power for when there isn't sufficient sun to produce it. He had tanks for storing the hydrogen given off from the charging batteries, he conberted his 82 F-150 to run off of it, looked like a LPG kit. When you think about all the gas hikes we've been plauged with over the years, this guy sure had the right idea, wish I had known him, sure could have learned a lot.