How Nitrous Oxide in Cars Works

Nitrous Oxide breaks into Nitrogen and Oxygen.
Nitrous Oxide breaks into Nitrogen and Oxygen.
2007 Microsoft Corporation

Automotive enhancements are range from suspension upgrades to turbochargers, but few garner as much intrigue as nitrous oxide in cars. And it's easy to understand why.

Popularized by street racing culture and immortalized in various movies and video games, nitrous oxide (N20), commonly known as "nos," remains a subject of intrigue and excitement. Still, few understand the science and mechanics behind this powerful, engine-boosting tool. It's time to take a closer look.


What is Nitrous Oxide?

Y­ou may have read this article about how sodium chlorate acts as a way to store oxygen. You release the oxygen in sodium chlorate by heating it. It turns out that nitro­us oxide (N20) works exactly the same way. When you heat nitrous oxide to about 570 degrees F (~300 C), it splits into oxygen and nitrogen.

So the injection of nitrous oxide into an engine means that more oxygen is available during combustion. Because you have more oxygen, you can also inject more fuel, allowing the same engine to produce more power. Nitrous oxide is one of the simplest ways to provide a significant horsepower boost to any gasoline engine.


­Nitrous oxide has another effect that improves performance even more. When it vaporizes, nitrous oxide provides a significant cooling effect on the intake air. When you reduce the intake air temperature, you increase the air's density, and this provides even more oxygen inside the cylinder.

The only problem with nitrous oxide is that it is fairly bulky, and the engine needs a lot of it. Like any gas, it takes up a fair amount of space even when compressed into liquid nitrous oxide. A 5-liter engine running at 4,000 rotations per minute (rpm) consumes about 10,000 liters of air every minute (compared to about 0.2 liters of gasoline), so it would take a tremendous amount of nitrous oxide to run a car continuously. Therefore, a car normally carries only a few minutes of nitrous oxide, and the driver uses it very selectively by pushing a button.


Types of Nitrous Systems

Nitrous systems can be broadly categorized into two types: "wet" and "dry" [source: Kim].

  • A wet system mixes nitrous with additional fuel outside the combustion chamber, typically in the intake manifold. This method ensures the correct air/fuel mixture enters the combustion chamber.
  • A dry system introduces nitrous oxide alone into the intake tract, relying on the engine's existing fuel system to provide the additional fuel needed. These systems are often used in vehicles with sophisticated fuel injection systems that can adjust fuel delivery in response to the nitrous.


Components of Nitrous Oxide Systems

A typical nitrous oxide system includes several key components, including:

Nitrous Oxide Tank

The nitrous oxide tank stores liquid N2O, and is usually made from high-strength materials built to withstand the pressure involved [source: Honeycutt]. On one end, these tanks are outfitted with a pressure release valve for safety. Tank size can vary, allowing for user customization.


Solenoids and Delivery Lines

Solenoids, or electronically controlled valves, manage the flow of nitrous oxide and fuel into the engine. They ensure the correct ration of nitrous and fuel is maintained for performance and safety. Equally crucial are delivery lines, which are made of high-quality materials and aid in the transport of nitrous oxide and fuel from their tanks to the engine.

Nozzle or Plate

The nozzle or plate is the point at which the N2O is introduced into the air intake system of the engine. Each works slightly differently. A nozzle system injects nitrous directly into the intake stream, while a plate system is mounted between the intake manifold and the throttle body, creating a more even distribution.

Activation Switches

These let the driver control when the nitrous oxide is injected, and can range from simple push buttons to fully integrated systems that activate under certain conditions, like RPM targets or throttle position.

Pressure Gauge and Bottle Heater

A pressure gauge ensures that nitrous oxide tanks remain in the safe and effective range for operation. Some systems may include what's called a bottle heater, which helps maintain the nitrous systems temperature. This is particularly important in colder climates.

Purge Valve

The purge valve is an additional component designed to release nitrous oxide from the delivery lines before it enters the engine. This helps to remove any air pockets that could disrupt the nitrous flow, ensuring a more consistent and powerful boost.

Each component of a nitrous system plays a vital role in ensuring the system's performance, reliability, and safety. From the storage and delivery of nitrous oxide to the precise control and activation of the system, understanding these components is essential for anyone interested in utilizing nitrous oxide to boost their vehicle's engine performance.


Safety and Risks

While nitrous oxide systems can dramatically increase performance, they come with risks. First, it's crucial to ensure that the engine and drivetrain components can handle the increase power associated with nitrous oxide kits. Proper installation is critical too.

Improper installation or use can lead to engine damage or even explosions [source: Airgas]. It's essential to use these systems in compliance with safety standards and preferably under the guidance of professionals. Finally, users should be aware of the legal implications nitrous oxide use on public roads, as it's use may be restricted or prohibited in some areas.


Nitrous oxide systems provide an effective and exhilarating way ato boost a car's performance. By understanding how N20 works and adhering to proper safety guidelines, enthusiasts can safely enjoy considerable power gains. Whether for competitive racing or simply enhancing the driving experience, N2O remains a popular choice for those looking to get the most out of their vehicles.

Nitrous Oxide Engine FAQ

How does nitrous oxide make a car go faster?
When nitrous oxide is heated to 570 degrees F, its molecules split into nitrogen and oxygen. This means more oxygen is produced for combustion, allowing the engine to produce more power in the process.
Is NOS street legal?
Nitrous oxide systems, also known as NOS, may be permitted for use depending on local city regulations. NOS is legal to use in some classes of auto sports.
Does nitrous damage your engine?
No. Using high-quality nitrous that's been fitted correctly and according to the requirements of your car should be safe for the engine and will not cause the engine to overheat or explode.
How do you apply nitrous to a car?
You will first need to find the safest place to mount the nitrous bottle. You will then have to install a nitrous line by removing the carburetor and setting up the nitrous plate. There is also quite a bit of wiring involved, which is why it is always best to hire a professional.
Can you buy NOS for your car?
Nitrous kits are available and can be easily installed in cars. They are also more affordable as compared to a turbo system or supercharger for your vehicle.