The concept of nitrous oxide being used in cars is one that stemmed in the 1970’s by two successful automotive technicians and racers named Mike Thermos and Dale Vasnaian. The use of nitrous oxide for there forward has only served in improving car performance and racing development stemming from a solid relationship forged between NOS and leading racers and engine developers worldwide. The hype of nitrous oxide injected cars really took off with the advent of the popular movie The Fast and the Furious.
Nitrous oxide is a combination of two parts nitrogen and one part oxygen hence the scientific formula N20. Nitrous oxide is colorless, nonflammable, and sweet smelling. It is used medically as a light anesthetic predominantly in the dentistry fraternity. In cars, nitrous oxide is stored in canisters in a liquid form. Drivers using nitrous oxide have to do so sparingly as a result of limited storage space. The boost given is usually only enjoyed in short spurts and is commonly activated by a button on or around the steering wheel.
In an internal combustion engine, the ignition created by the spark plug causes a combustion of the fuel-air mixture. This explosively burning mixture of fuel and air is what ultimately gives the car power. As can be imagined, the more oxygen within the combustion chambers, the more power. Nitrous oxide, being a compound of nitrogen and oxygen, is split into its individual molecules at 296 degrees Celsius. At this temperature, the loose oxygen molecules are burnt with the available air already in the chamber causing additional power.
The question which now arises is “What happens to the available nitrogen atom”? Surely, if it was only more oxygen that was needed to create that extra power, then injecting pure oxygen would have been a much more viable option? However, the heat created with an onslaught of just oxygen molecules would create far too much heat ultimately leading to engine malfunction.
Nitrogen serves a dual function. Firstly, the nitrogen atoms have a cooling effect on the combustion temperature by absorbing the heat and carrying it away. Nitrogen can effectively cool the intake temperature by 16 to 24 degrees Celsius (i.e. approximately 60 to 75 degrees Fahrenheit). Secondly, with every 10 degree Fahrenheit drop in temperature your total horsepower output will increase by approximately one percent. This means that over and above the power output derived from the oxygen-petrol combustion process, your horsepower output will also increase by about six to seven percent (i.e. 60 / 10 and 75/10 as mentioned above).
Conclusion: Having the correct air fuel mixture when using nitrous oxide can be a tricky process. An over diluted air-fuel mixture could cause detonation problems which will lead to inevitable engine damage. A rich air-fuel mixture may cause your car to lose power as the demands of the engine become too high. Ultimately, it’s all about fine tuning, learning, and enjoying the experience.