Laughing Gas in Cars

                Remember that time at the dentist’s office when you had to undergo a procedure and laughing gas was used to sedate your senses? Laughing gas can be a significantly helpful anesthetic for dental and even medical purposes, but the versatile chemical can also be used as a fuel “supplement” in automobiles and aircraft. Because of its chemical properties, nitrous oxide (N₂O), also known as laughing gas, is commonly used in vehicles, especially in those built for racing, as an aftermarket modification that considerably enhances performance and gives the car an extra push.

However, the overly substantial performance gains of nitrous oxide systems (NOS) have been deemed by many countries as extremely dangerous, hence the installation and use of nitrous oxide in civilian automobiles are not street legal. Moreover, while legal and generally allowed, even professional racing has restrictive policies on the use of NOS. For instance, racing, such as NASCAR, have completely banned and harshly fine and penalize for use of NOS in their cars. On the other hand, those nicely-tuned sports cars we saw in Montalcino were built specifically for rally racing; since rally race tracks are generally off-road and on a closed course, there are no strict vehicular modification regulations. Therefore, in addition to robust off-road tires, forced induction, and other performance modifications, those rally cars were probably all equipped with huge, expensive NOS systems. Racers (whether street or professional) and car enthusiasts actually have very good reason and logic behind installing and using nitrous oxide. These high-performance cars have tens of thousands of dollars put into them by their owners and the racing companies just for them to win a race and take home the prize. If installing a few hundred dollar (maybe a few thousand max for top-notch parts) nitrous oxide system would give them a significant performance boost and possibly the winning edge, the benefits and winnings outweigh the relatively meager cost and risk. To demonstrate the potential, even with second-rate NOS systems, the performance increase can provide up to several hundred more horsepower to a car.

Now that there’s a logical reason and sensibleness behind NOS systems for racing and performance cars, how and why does an anesthetic like laughing gas have a strange and completely extraneous dual purpose of being such a tremendous car enhancement? It all lies within the characteristics of nitrous oxide and the chemical reaction that occurs in a vehicle’s internal combustion engine. Nitrous oxide, being N₂O, is composed of 2 parts nitrogen and 1 part oxygen; oxygen alone contributes 33% to the compound’s molecular makeup and 36% to the molecular mass. Most importantly, nitrous oxide is considered oxygen-rich compared to atmospheric air, which only has a 23% oxygen composition. If you recall my first blog post titled, “Europe- Why Small Cars?,” the mentioned combustion reaction in a car’s engine directly relates to and logically explains the purpose and application of N₂O. The chemical reaction in a standard vehicle’s engine combines oxygen and a fuel in order to produce the required exothermic energy, thereby driving the car. If the amount of oxidant, which is oxygen, is increased and a stoichiometrically equal amount of fuel is also included, the output energy of the exothermic reaction would similarly increase, providing more power to the car. That’s where the ingenious and ideal properties of nitrous oxide come into play; the chemical content of nitrous oxide can contribute and also act as an oxidant in the combustion reaction by adding more oxygen. At a high temperature, approximately 572⁰F, nitrous oxide breaks down and decomposes into their chemical components, nitrogen and oxygen. The released oxygen from the nitrous oxide feeds into the combustion chamber, also known as the piston and cylinder of an engine, and acts as extra oxidant in addition to the air from the intake. Also, the use of liquid nitrous oxide is much more advantageous than the gaseous oxidant. In closed and pressurized containers, nitrous oxide exists in its liquid form, which is a lot denser than gaseous nitrous oxide. Because of the increased density, liquid nitrous oxide is the preferred state and method of delivery in a car’s NOS system. More liquid nitrous oxide would take up less space than the gaseous form and therefore, more oxygen could be pumped into the given amount of volume. In the rigid combustion piston cylinder of an engine, pushing in more oxygen as the oxidant would produce a greater output, so liquid nitrous oxide would be very beneficial.

Using liquid NOS systems in cars clearly has advantages towards a car’s performance. It is definitely worth it to install and inject nitrous oxide into a performance engine to get the most bang out of the car for the buck. Of course, this is assuming the vehicle will be used for safe, racing purposes and will put you in the winning spot.

Resources:

http://www.thirdgen.org/nitrous

http://www.competitionplus.com/05_20_2004/n20_myths.html

http://www.tuningmadeeasy.com/tuning/tuning-with-nitrous/