Dr. DonWG,
Dumb question, just trying to learn.
What would happen if you sprayed a real small dry shot (30HP max) in the intake tract, about 18" before the turbo inlet?
Actually, that would be a very safe way to do it, and probably the way I would go if I were trying to use a single nozzle. The nitrous would have plenty of time to change state from a liquid to vapor and get mixed with the air very well. You would then only have to worry about the injector being able to supply the needed extra fuel. A device that would raise fuel pressure a certain amount whenever the nitrous was activated could be used. Old school, but affective with a small shot. If you were running an ECM that had an auxiliary fuel map that could be switched to whenever the nitrous was activated, that would seem to me to be the better way to go. I would try my best to figure out a system that introduced the extra fuel through the existing port injectors. There may be a timing problem that would have to be hashed out though. If both the nitrous and the extra fuel were activated at the same time, the fuel would definitely get to the cylinder before the nitrous. And when the system was shut down, there would still be nitrous in the intake system that would need to pass through the engine still, but the fuel would be shut down. I'm not sure about depending on the O2 correction to do it for you.
See, the big problem I see with a wet system on a GN is the dog house intake. Introducing the nitrous and fuel in the up pipe is going to be a distribution nightmare. The 2 front cylinders are a right angle flow path after the throttle body. If the nitrous AND fuel haven't vaporized by that point, there is very little chance you will have good distribution. If you make sure that the nitrous to fuel ratio is on the rich side, you may keep from going too lean. I would go at least one fuel jet size richer than the chart suggests. Do some very short testing and check plugs.
That's another thing. I would not run a single nozzle system long duration. The engine can tolerate a lean nitrous/fuel mix for a very short time. If that time can be enough to get on the turbo, then mission successful. If you try to run the nitrous full pass or maybe 2 to 3 seconds with a few cylinders too lean, you're going to have problems.
The more I try to figure out a safe single nozzle system, the more a port injection system looks to be the simpler, easier and safer way.
If you study it, you'll notice the nitrous companies will start suggesting a port system at a certain system hp level. They realize that with the larger percentage of nitrous/fuel to normal air/fuel, there is a far greater chance of engine damage from the inherent distribution problems of a single nozzle system. The intake charge is much cooler because of the greater amount of nitrous being injected and the coolness of the mixture does not do much to help vaporize fuel. As I stated in an earlier post, liquids do not like to make turns.
