Combustion Cycle is made of Air/Fuel and Spark. You make more power by adding to all three, but all three have to be kept in balance. If you add Air you have to add fuel. Adding Nitrous is adding Air, so you have to add Fuel as well.
Wet-Kits: Wet-Nitrous either uses it's own supply of gas or taps a fuel line and injects gasoline via an extra injector solenoid. Wet kits allow for precise fuel metering, but can strain the fuel system if they scavange too much.
Dry-Kits: Dry kits rely on "existing" Fuel sources to provide the extra gas. Extra gas is accomplished through either increasing the fuel pressure, or having the computer add more fuel. 10 years ago Dry kits normally meant either adding fuel pressure by injecting nitrous into the fuel-pressure regulater vaccum control line or adding it via a computer modification to the ECM. Today "dry kits" typically blow through a Mass Air Flow Meter and rely on it to detect the extra oxygen and provide more gas. Advatanges: Easy to install. Disadvatages, you're asking the fuel system to do something it wasn't designed to do and that can cause problems.
I'm not sure why....maybe MOL can drop some knowledge on why....but I've heard many people say don't do dry...unless you got money to burn. I've been told wet is the way to go. Easier to maintain and cheaper maintenance wise
when you run a dry kit the only why the motor sees anymore gas is by reading the o2 sensor. and by the time the o2 makes the change it is to little to late. dry kits are only used on cars that add very small amounts of horsepower or cars that have stand alone injector tuning, which we do not have. wet systems are the only why to go. you can have control over the amount of fuel that the nozzle/plate sees and it does not affect what the computer needs to adjust for.
first never call it nos that is a company that makes nitrous products, it is nitrous oxide, next get a zex kit it is the best compleate kit for a 1st time user of nitrous with a full nitrous install guide, you will need a bottle warmer and a blow down tube kit if you want to go to the track and use it, the zex kit will have all the jets for a 75 shot or 100 shot or 125 shot, come with bottle, bottle brackets, nitrous lines, nitrous jets, the tps sensor,(throttle position sensor) and the housing for the silinoids, the fogger for airbox and your arming switch and all nessisary wireing and bolts hardware. seprate is bottle warmer and blow down kit ( witch will need a 1/2 in hole drilled through body) but so will the nitrous line if you install it were the spare tire go's.... you can run a 75 shot or 100 shot without anything done.. anything above a 100 shot you really need to have a tune with timing pulled...... 90 % of failer of nitrous is user error.....