Nitrous Oxide has been common in the aftermarket vehicle industry for the past 50 years and continues to be the best way to gain appreciable power without heavily modifying your engine. Most late-model vehicles only require a small hole drilled into the intake tube, a tune, and a few wires tapped to have a basic nitrous kit installed. All of this can be easily reversed to return to stock.
Nitrous comes in two grades, USP (Medical grade) and automotive-grade. Both are the same compound, but the automotive nitrous has a tiny amount of sulfur added to discourage inhalant use. Our atmosphere is around 78% nitrogen and 21% oxygen, and the rest are traces of other elements. In the ever-progressing pursuit of more horsepower, we know that we have to burn more fuel and oxygen to make more power. There is only so much theoretically that an engine can consume without some type of help, which can come from forced induction or chemical induction. Nitrous is on the chemical induction side and increases oxygen concentration in a given combustion cycle without increasing manifold pressure.
Nitrous Oxide is composed of two nitrogen molecules and one oxygen molecule. By weight, it is 36% oxygen. The nitrous is stored as a liquid in your bottle and typically stays in liquid form until it exits your nozzle(s), plate, or spray bars. Nitrous boils (reverts to gas form) at -129*F at atmospheric pressure, and this rapid phase change and temperature drop is what drops your intake air temps and is one of the ways it helps you make more power. Once the nitrous is inside the combustion chamber, it undergoes another transformation. The chemical chain breaks down at around 570*F, and the oxygen and nitrogen atoms separate. This allows the combustion to consume more fuel, thus making more power. For the most part, the nitrogen is just a byproduct and leaves through the exhaust, but it does have a minor heat absorption effect. Nitrous Oxide itself is not flammable or explosive; However, it is an accelerant and will make any fire that is already burning worse. There are many safety measures on modern systems to prevent bottle blowouts, line ruptures, and damage to engines or their components. Make sure you look up and follow the instructions for whatever kit or product you are installing, and give us a call if you have any questions!
Dry nitrous systems are the simplest of nitrous kits. They inject only nitrous into the engine, and fuel is applied after the fact through a standalone ECM. For this reason, the majority of vehicles out there cannot safely run a dry nitrous kit and should run a wet kit, which injects nitrous and fuel (Through separate solenoids, with the fuel sourced from the fuel rail or a regulator) into the engine, allowing you to control the nitrous-to-fuel ratio without adjusting the amount of fuel that the motor gets when the nitrous is off.
Because you are introducing more oxygen and fuel into the cylinder, your cylinder pressure will rise, you will make more power, and you will need to retard your timing to make sure the now quicker combustion happens at the right time. On most modern EFI vehicles, you will need a tune to pull this timing. The exceptions in the late model world are the LS and LT-based vehicles, which can use a Lingenfelter timing control box to pull the timing whenever the nitrous is on. Older or carbureted vehicles typically run a timing control module to pull this timing.
Nitrous can be an easy and relatively inexpensive way to gain a little power on your stock late model vehicle or a potent game-changer on your drag racing engine. When you need more power, nitrous is a solid option.