The Science of NASCAR

The sport of NASCAR and chemistry go hand in hand. Underneath the hood of every race car, chemical reactions are taking place at a rapid place. The drivers and association of NASCAR heavily rely on the science of chemistry for the safety of the drivers and the functioning abilities of the race cars. One of the biggest concerns for NASCAR is ensuring the safety of their drivers. Some of the ways NASACAR is able to protect its drivers is through durable windshields, specially designed helmets, custom five point harness, custom gas tanks and a cooling system. The windshields of a race car are extremely durable yet very soft as it is made of a material called Lexan. Lexan is made from a thermoplastic polymer known as polycarbonate. Lexan is also used to make iPods CDs DVDs and is the chief component of bulletproof glass. Although Lexan windshields can be easily dented or scratched but will not shatter. In addition to the windshields, NASCAR drivers are also provided with helmets that are specially designed for them. These racing helmets are made of three main components consisting of the outer shell, a foam liner and a form-fitting inner liner. The hard outer shell is coated with a composite of carbon, glass, and Kevlar which is an extremely tough polymer that is also used in bulletproof vests. Underneath the outer shell is the foam liner made of polystyrene or polypropylene. The final component of the helmet is the foam-fitting inner liner is composed of either nylon or Normex, a fire-resistant material. These helmets are designed to withstand 300 Gs of force. Gas tanks used in race cars usually hold 22 gallons of gasoline. The tank is composed of an inner elastic bladder made of a thermoplastic elastomer. The tank is also filled with polyurethane foam, which prevents the sloshing of fuel. The foam also absorbs some of the impact from an explosion. Additionally, temperatures could easily reach 150F within the car during a car so solid carbon dioxide is used within the cooling system. The stream of air cools the driver through the endothermic process of evaporation.

The science of Chemistry also helps race cars function and perform. NASCAR cars have V-8 engine which consists 8 cylinders with pistons pumping within them in a V shape to reduce engine vibration. The volume of each cylinder is known as its displacement. Typical NASCAR cars have an engine displacement between 5735 cc to 5867 cc. Within each cylinder is a piston which is rounded piece of cylindrical metal fitted to move up and down rapidly within the cylinder. As the piston moves upward, gases within the cylinder are compressed. As the cylinder moves downward, the gases with in the cylinder expand. As the piston pump up and down, a connecting rod attached to the piston is connected to the crankshaft which then rotates quickly ultimately causing the tires to spin. To get the pistons working, a mixture of fuel within each cylinder is ignited by a spark from the spark plug. As the fuel combusts, it undergoes a chemical reaction, yielding gaseous byproducts. Liquid gasoline doesnt burn, meaning the vapour above the liquid burns. The chemical equation for the combustion of octane within gasoline is: 2C8H18 (g) + 25O2 (g) = 16CO2 (g) + 18H2O (g). The reaction is highly exothermic meaning it releases energy into its surroundings causing the pistons to move within the cylinders.

Although NASCAR race cars do use gasoline, the type used by NASCAR is leaded 110-octane gasoline. The lead is a form of a compound called tetraethyl lead, which reduces engine knocking. Knocking is the loud clanging noise made when the fuel in the cylinder is ignited early. This particular type of gasoline also contains Pb (CH2CH3) which improves the performance of the gas and preventing it from igniting as it is compressed. Octane ratings can be determined by a formula that represents the average resistance of the gas to the engine knock or the amount of fuel can be compressed before it automatically ignites. The higher the octane rating, the more gas can be compressed in the cylinders before ignition resulting in more fuel being burned and more power. Octane is a hydrocarbon which can be easily compressed without igniting while isooctane, an isomer of octane, is even better at being compressed without igniting. Isooctane is also better than octane because isooctane is more of a stable compound then octane. The combustion of isooctane requires a greater activation energy then octane and is therefore less likely to ignite due to increase pressure. Additionally, tires are a key part of a race car. These tires are very thin to prevent friction between the tire and the road and have no treads producing better traction. These tires are also often inflated when their first installed. This is because as the race progresses, the temperature of the tires increase resulting in a higher pressure in the tires which is in accordance to Gay-Lussacs law. Furthermore, NASCAR tires are filled with nitrogen because nitrogen contains less moisture. As the temperature of the tires increase, moisture in the tire vaporise and expand affecting the handling of the car. In conclusion, without chemistry, the sport of NASCAR would not be the same as the sport many enjoy today.