How Does Nitrous Boost a Car?

By July 19, 2020August 23rd, 2020Performance Modification

Nitrous seems like black magic doesn’t it? Press a button and the car goes flying. But how do they work exactly? Let’s cover that in detail today.

Nitrous boosts a car’s performance by increasing the amount of oxygen molecules in the combustion chamber. More oxygen means more fuel could be ignited. Thus, creating a much bigger combustion to increase performance. Nitrous is compressed Nitrogen Oxide (N2O). When exposed to high temperature, the Nitrogen and Oxygen molecules will split – thus providing the extra oxygen molecules to increase performance.

Let’s discuss nitrous in more detail: how many horsepower is added, requirements before adding a nitrous and many more! And yes – nitrogen oxide is also known as the laughing gas. But that’s not what it’s used for in the automotive industry 🙂

Summary

  • Nitrous is compressed Nitrogen Oxide (N2O). Nitrogen Oxide is made of Nitrogen and Oxygen molecules. When inserted into the combustion chamber, the Nitrogen and Oxygen molecules will split. Thus, increasing the amount of Oxygen for bigger combustion.
  • The amount of horsepower added depends on how much nitrous you inject. For example, 50 shots of nitrous will provide additional 50 horsepower.
  • There are no engine requirements to install a nitrous. It will also work on stock engines – but with limits. 
  • It is typically legal to install nitrous. However, you are encouraged to check with your local laws. Different states have different regulations.

How Does a Car Engine Deliver Power?

Before we talk about how nitrous increases performance, we first need to understand how your car engine delivers power. Car power comes from combustion when fuel is ignited in the combustion chamber. When a combustion occurs it uses up the oxygen molecules inside the combustion chamber. To have bigger combustion, you need more fuel and oxygen molecules.

If you increase the amount of injected fuel without increasing the amount of oxygen, then not all the fuel can burn. All the unburnt fuel will simply exit the car through the exhaust – resulting in no performance gain and horrible fuel consumption. Increasing the amount of injected fuel is easy. Increasing the amount of oxygen is the hard part.

This is where performance modifications come into place – typically they are designed to suck more air into the combustion chamber. For instance, turbochargers and superchargers work by sucking in additional air, compressing it and then directing it into the combustion chamber – resulting in additional oxygen molecules. Other performance parts like performance air filter and cold air intake aim to naturally increase the amount of air that’s sucked by the car’s air intake. If you are interested, I cover turbochargers in this article and performance air filter in this article.

Nitros is similar – it aims to increase more oxygen in the combustion chamber. However it works a little differently.

Image of a car drifting

Why Not Boost Performance With Oxygen Tank?

Till this point, we have understood the point: To have more power, we need to increase the amount of oxygen in the combustion chamber. So why not simply inject extra oxygen in the chamber using an oxygen tank?

This is a very good question! In fact, this was tried in the 1950s. The results were disappointing. Even before the oxygen molecules could reach inside the combustion chamber, they began to explode in random areas that were hot enough.

This is where nitrous aka Nitrous Oxide (N2O) come into the picture.

How does Nitrous Boost Performance?

As I have already mentioned – nitros is actually compressed Nitrous Oxide (N2O). Unlike oxygen Nitrous Oxide is not flammable. Thus, it won’t simply explode. However, once Nitrous Oxide is exposed to a high temperature (570 degrees F), the nitrogen and oxygen molecules will split. This splitting results in additional oxygen molecules at the right location (combustion chamber).

With this, the carburetor can now inject additional fuel to create a much bigger combustion and deliver extra performance. This time though, all the fuel can combust properly because there are enough oxygen molecules in the chamber. By the way, a carburetor is the tool that mixes fuel and oxygen in the combustion chamber.

Very simple theory right? 🙂

How Many Horse Power is Added By Nitrous?

The amount of horsepower added depends on the amount of nitrous you release into the combustion chamber. It’s literally buying speed for your car. For example, 50 shots of nitrous will provide additional 50 horsepower. All you need to ensure is installing the right nitrous kit that gives you the right shot. Some kits provide one horsepower for one shot while others provide more horsepower per shot.

The performance gain also depends on multiple other factors. The most common ones being your tires and how stock your engine is. To handle the sudden performance boost, your tires must have good grip. Worn out tires will hinder the performance gain you receive. Worst case scenario, bad tires can simply blow out and send your car spinning.

On the other hand, typical stock engines that are not tuned in any way, can typically handle 75 hp gains without any problem. Higher end cars that equip a performance-oriented stock engine can handle 150 horsepower gain. Anything above 150 horsepower gain will likely require engine turning to handle the performance gain. Stock engines simply cannot handle the heat and pressure that comes with the power.

GIF of dancing nos man

Nitrous Dry Injection Vs Wet Injection

Dry injection is when you inject the nitrous by itself – without any fuel mixed in it. This means you have to increase the fuel injection manually by tuning the ECU or carburetor. In dry injection, if you do not adjust the ECU or carburetor that means the car will run with too little fuel in the combustion chamber. Extra oxygen is present by the nitrous but not enough fuel is injected.

Wet injection is when you inject nitrous together with additional fuel. This means you do not have to adjust the amount of fuel injected by the carburetor. All the incoming nitrous already has its own fuel to burn. 

Dry injection system is much easier to install and is an easy way to add power. However, achieving an optimal air/fuel ratio is difficult. The fuel injection value is already fixed during the initial ECU tuning. Optimal air/fuel ratio is important to make sure your car is not running with too much fuel or too little fuel. 

Wet injection systems are much more complicated to set up – it requires more fine tuning to work properly.  However, you can be sure that optimal air/fuel ratio is achieved every time. Also, wet injection system can potentially produce more power because it always makes sure enough fuel is available to compensate for the extra oxygen from nitrous.

Any Requirements Before Equipping Nitrous?

No – you can install nitrous  on a stock engine. You just have to ensure that you install an appropriate nitrous kit for your engine. Four-cylinder engine normally allows for an extra 40 to 60 horsepower. Whereas Six-cylinder engines allow for an extra 75 to 150 horsepower. If you want more power than  that, you might need to tune your car to accept this performance gain.

Is It Legal To Install Nitrous? 

If you are in the US – installing nitrous is legal. However, this depends on which state you are on. Some states like California have a much stricter emission law, whereas Texas is more relaxed. So it is best to check with your local authority or state law to find out what is legal and what is not.

Cons of Nitrous Oxide

Image showing storage space required by nitrous tank

The pro is very simple. You get a significant spike in performance. But with this great power, what’s the cons?

 

Expensive

Nitrous can get very expensive and they run out very quickly! Your car engine uses up a lot of air when it’s combusting. There’s only so much compressed nitrous you can fit into a tank. Let’s break down the economics real quick:

  • 10 pounds of nitrous can get you 2.5 miles
  • Nitrous typically cost $5 per pound
  • That means $50 per 2.5 miles of distance

See what I mean? $50 for every 2.5 miles traveled. Damn that’s steep! But hey, it can get you to that 2.5 miles distance pretty quickly ;). 

 

Wear out your engine

With nitrous, your car engine will produce a much bigger combustion. Aside from the performance, this also brings significant extra heat and pressure to your engine. Without realizing it, your car engines like the pistons will wear out quickly. 

 

Huge Storage Space Required

Nitrous is stored in a form of compressed liquid. This requires big and heavy tanks to store it – usually in scuba sized tanks. How many of these scuba sized tanks can your car fit? 🙂 

 

Does Not Last Long

To put this into perspective, a typical 5 litre engine going at 4,000 RPM uses 10,000 litres of air per minute. 10,000 litres! You are going to need a gigantic tank to store that amount of nitrous – and your car does not have space for that. Thus, nitrous is stored in scuba sized tanks. You could probably use a few minutes of those before they run out. This is why nitros are only used in short bursts. 

Which muffler is your car right now?

Should I Install A Nitrous?

If you are drag racing – go for it. Nitrous is very popular in drag racing. If you don’t install nitrous, chances are your competition will and they will be way ahead of you. If you want to use nitrous on the street – absolutely not. It could be illegal and get you in a lot of trouble. Plus, it’s very expensive and needs refilling often, so why bother? Just look at all the cons I just covered.

Conclusion

I have covered a lot of grounds on nitrous in this article. I hope you find it an interesting read. If you want to know more about car performance in general, then check out my other articles! Thanks for reading 🙂

Ifandi S.

Ifandi S.

Passionate about everything mechanical. Ifandi has been involved with motorcycles and cars since the old days - in his family's auto parts shop. Want to keep in touch? Scream "STRAIGHT PIPEEEEE" at the top of your lungs and Ifandi will show up.

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