NITROUS OXIDE

In modern automobiles, nitrous oxide (often just “nitrous” or “Nitro” in this context) is sometimes injected into the intake Manifold (or just prior to the intake manifold) to increase power: even though the gas itself is not flammable, it delivers more oxygen than atmospheric air by breaking down at elevated temperatures, thus allowing the engine to burn more fuel and air. Additionally, since nitrous oxide is stored as a liquid, the evaporation of liquid nitrous oxide in the intake manifold causes a large drop in intake charge temperature. This results in a smaller, denser charge, and can reduce detonation, as well as increase power available to the engine.  

The gas was discovered by Joseph Priestley in 1772.

Humphrey Davy in the 1790s tested the gas on himself and some of his friends, including the poets Samuel Tyler Coleridge and Robert Southey. They soon realized that nitrous oxide considerably dulled the sensation of pain, even if the inhaler were still semi-conscious, and so it came into use as an anesthetic, particularly by dentists, who do not typically have access to the services of an anesthesiologist and who may benefit from a patient who can respond to verbal commands.  

The objective of nitrous oxide is to make more horse power, which is achieved in not exceed that which the intake system can flow. This prevents fuel “puddling” or distribution problems.

      

A further advantage of a ‘Wet’ system is that it lends itself to fine- tuning. By adjusting the fuel pressure and fuel orifice, either up or down from the base line, the system’s performance can be further improved. In addition, on a direct- port nitrous system each cylinder can be fine tuned to optimize performance and overcome rich or lean cylinders that the engine may have neutrally aspirated.

The internal- combustion engine is basically a large air pump and its ability to pump air is one of the factors, which determine how much power it can produce. Air contains oxygen and by drawing more oxygen into the combustion chamber, more power will be produced. In order to achieve efficient combustion, two ways. Firstly, nitrous oxide comprises one-part oxygen and two-part nitrogen. This is a much higher percentage of oxygen than that found in the atmosphere and, because of this; the additional oxygen being forced in to the combustion chamber provides more potential power. Nonetheless, the additional power cannot be realized safely without enrichening the amount of fuel in the combustion chamber. The second way nitrous oxide will increase an engine’s horsepower is by cooling the air charge from the atmosphere.

    

One of the most important aspects of keeping an engine healthy when using nitrous oxide is to ensure it operates at the proper air/fuel ratio. Running too lean can cause detonation, resulting in damaged engine parts. Running too rich can also harm performance and destroy engine parts, too. Once calibrated, they’ll inject the proper amount of fuel with the nitrous system to maintain the correct air/fuel ratio. It should be ensured that the amount of nitrous that the system is engineered to dispense does the air

needs to be mixed with fuel in the correct ratio. The stoichiometric (chemically correct) ratio is for basic gasoline is 14.7 parts air to 1 part of fuel.

  

Greater quantities of oxygen can be drawn into the combustion chamber by simply introducing nitrous oxide. By weight, Nitrous contains 36% oxygen while air has only 23%. A charge of nitrous oxide is capable of burning much more fuel than the equivalent amount of air.

Because nitrous is more oxygen-rich than air, the recommended air fuel ratio becomes 9.5 part of nitrous to 1 part of fuel (9.5:1). That means when oxygen-rich nitrous is introduced additional fuel must also be supplied in order to maintain the optimum ratio Without the additional fuel the mixture would become dangerously lean-circumstances that will almost always lead to server and expensive damage.         

For racing purposes, nitrous oxide is usually contained in an aluminium cylinder; available in a variety of sizes ranging from 2.5 lbs to 20 lbs. While retained in the cylinder the nitrous is in a liquid from and held under high pressure. When it is released from cylinder into the intake tract its physical state changes from a liquid to a gas. This transformation occurs as the nitrous is released from an area of extreme pressure (the aluminium cylinders are pressurized to approximately 1000 P.S.I.) into the vacuum of the intake manifold. This change in state is usually referred to as nitrous ‘boiling’.

      

It takes energy to enable the nitrous to expand and boil. This energy is produced by the heat, which is absorbed from the surrounding air/gas in the intake tract. The end result is an intake charge that is cool, dense and oxygen rich-the ideal recipe for producing more power.

When the additional fuel required for nitrous is introduced in such a way that it is exposed to the full force of the expanding nitrous, it is atomized completely. This promotes improved burning in the combustion chamber and, as a direct result, power-output is increased.

Nitrous oxide (also known by the chemical formula N2O) comprises to atoms of nitrogen and one of oxygen and the heat of the combustion break the chemical bond that holds them together. Without heat, the three atoms would remain bonded and, consequently, the oxygen atom rendered powerless – unable to play its role in the combustion process. This is why inhaling nitrous can lead to asphyxiation, even though it has higher oxygen content than air. Your body cannot produce the heat necessary (about 525Fahrenheit) to break the bond between the nitrogen and the oxygen; leaving the oxygen content useless for respiration.

Gasses are often considered in terms of moles. The definition of a mole is the amount of substance that contains avogadro’s number of atoms or molecules. Through this number remains the same (6.0210 to the power of 23), the weight of a mole will vary depending on the atomic weight of the molecule in question. A mole of any substance occupies 22.4 litters at standard pressure and temperature. The fact remains that all gasses have the same molar volume in similar conditions. So, if a cylinder can draw two moles of air on a intake stroke, it can also consume the same volume of nitrous, which is 50% oxygen. For every two moles of Nitrous Oxide (N2O) introduced to the cylinder, there are two moles of Nitrogen (N2) and one mole of oxygen (O2 ), as can be seen in the equation below.

2N2 O è2N 2+1 O2    

There lies the hidden advantage of Nitrous Oxide. Since every mole has the same volume, its clear that two moles of nitrous drawn the cylinder become three moles through the combustion process. This further raises combustion pressure and increase s the power- producing potential of the engine.