HOW NASCAR RACE CARS WORK
PART II
THE LONGEST LIST OF THE LONGEST STUFF AT THE LONGEST DOMAIN NAME AT LONG LAST

How do NASCAR race cars work?

Super-speedway cars are designed much differently as their main purpose is to reduce drag. These cars can also go at much faster speeds and hold those speeds for longer periods due to the fact that the tracks they are designed for have higher banks, and are longer and straighter than short tracks. These cars are fitted with an engine that has a total force of 750 horsepower however, because these engines actually require reduced power, restrictor plates are used to cut the horsepower back to 450. Reducing the amount of drag becomes critical when the engine is not using all of its power. The body of the super-speedway car is also mounted to the frame sitting slightly forward so that it will also reduce drag and the fenders and sides are contoured to a sleeker and smoother shape – all in an effort to reduce drag. Because the tracks allow for much higher speeds, there is enough air delivered to the engine that it is not a safety issue. In fact, super-speedway cars are also tested in a wind tunnel however this time, they are tested to see the smallest possible grill opening that the car can handle to cool the engine and still reduce drag.

If the frame and body of a NASCAR racing car are important, the engine is then the absolutely most vital part of the car. These engines are extremely powerful and have unimaginable force however, they are really not that different than street cars. Dodge provides the engine block and cylinder head for the engines and they are based on a 1960 engine design that was a 340-cubic-inch, V8 engine. Although these engines are not exactly the same as the original design, they do have many similarities. They begin as the same size although they do get bigger as the original design is built upon, and they have the same cylinder bore centerlines as well as the same number of cylinders. They are also driven by pushrods, which is also how the 1960 design worked. One of the biggest differences is probably that these engines have the capacity to push out 750 horsepower without the help of turbochargers or supercharges. So just exactly how do they do it?

The engine, which is 358 cubic inches, is larger than the average car’s engineNASCAR racing cars also have intake valves, which stay open longer than regular cars, allowing more airflow to reach the cylinders. The intake and exhaust systems are also designed to maintain the air and fumes being created at such high speeds. There are no mufflers or catalytic converters to slow the car down and they are also designed with low restriction, which causes less resistance as the gases are moving through the pipes. There are also no fuel injectors found within these cars but instead carburetors that allow in huge amounts of air and fuel. The ignition systems also have customized spark timing, which makes the car as powerful as it can possibly be. Another difference between these engines and the engines within average cars is that they are all designed to operate under extremely high temperatures and speeds.

Once the engine is assembled, it’s checked to ensure that all the tolerances have been tightened. What this means is making it sleeker and refitting parts that are too large or that don’t fit just quite right. This adds to the car’s power as well because it’s not using excess power by having large gaps that wind gets through or by having pieces that are too large rub against each other, causing friction and slowing the car down. Once the engine has been completely assembled and all tolerances have been tightened, the engine is put through vigorous tests to make sure that it can withstand the pressure and that all of the tolerances have been tightened. These tests also allow the engines to be ‘broken in’, which is beneficial to the engine and helps it maintain superior performance. Although this is not as labor-intensive as constructing the body of the car, it’s the most important as any type of engine failure pretty much guarantees a lost race.

As important as the engine is pertaining to how the car performs, the tires as just as important for safety reasons. The tires move against the track at incredibly high speeds and although they are much more solid than regular car tires, they are still fragile enough to have occasional blowouts and having a tire malfunction at such high speeds is very dangerous. Not to mention that to increase safety, they must be changed at very quick speeds and they also have to be able to withstand extreme temperatures. In addition to all of this, they are expected to have excellent traction – that’s a lot to ask from just a tire!

The tires are generally deflated of their compressed air and filled back up with compressed nitrogen. This is because nitrogen has less moisture in it than just air and when the tire heats up, the moisture will expand and place pressure on the tires. With compressed air, this pressure could become too great and throw off the stability of the tire. This causes a great deal of change in the way that the car drives and the inconsistency can not only make it difficult for the driver but could also pose a serious threat. Tracks that are longer than one mile in length also require tires that have an inner liner. This liner is essentially a second tire mounted right inside the first tire. These tires allow the driver time to come to a controlled stop should the outer tire blow. The type of tire used will also depend on the type of track that is being driven on. This is because different tracks will have a different effect on different types of tires. Because of this and because NASCAR knows exactly what kind of tire material is needed for each different track, the compounds of the tire are closely regulated by NASCAR and Goodyear. NASCAR tires are designed without any tread and that’s because they provide more grip when they are driven against a track and their ‘sticky’ part is right against the pavement. Although bald tires are perfectly safe in NASCAR races when the weather is dry, they become even more dangerous in wet conditions. For this reason, NASCAR races are delayed, stopped, or rescheduled when it rains.

During a pit stop, a team of 7 people have a total of 12 to 14 seconds to change all 4 tires and refuel the car. Although the teams who fill this position are extremely skilled at what they do, there are a few tricks that help them to achieve this. Lug nuts are already placed onto a new tire that is about to be fitted onto a NASCAR car. They are held in place by an adhesive and so when the team begins their work, they can simply screw them in. These lug nuts are also long and have no threads for the first ¾”. This is to ensure that they don’t become cross-threaded and makes it easier to position the tire.

A NASCAR Race Car

PART 1

 

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