A look into how NASCAR's pre-race and post-race inspections are carried out.

It's 10 a.m. on a Sunday at Atlanta Motor Speedway, and the NASCAR garage is alive with energy. On the south side of the long steel building, four NASCAR inspectors carefully guide car after car through the inspection line, performing final checks on the sleek machines that will soon transform the quiet morning into five hours of non-stop thunder.

The teams drive the cars onto a raised platform where two inspectors fit a long aluminum template over the car's nose, roof, and trunk. The front inspector slides a small guide between the template and the hood, while the rear inspector does a final inspection of the rear wing. Meanwhile, another official uses a flat piece of aluminum to measure the side of the car.

Before the car leaves the platform, a team member climbs through the window and uses a heavy rubber mallet to tap on the sheet metal from the inside. Clearly, something isn't right, and the inspectors won’t clear the car until everything checks out.

At last, the car rolls off the platform and another one takes its place. Each competitor will follow in turn, one by one, on the same stage. As the cars leave, they join the starting grid, where 100,000 fans will soon cheer for their favorite driver during the Pep Boys 500, the seventh race in NASCAR's Chase for the Championship.

Each NASCAR race day sees 43 cars hit the track. Before any laps are driven, every car must pass a series of intense inspections under the watchful eye of Sprint Cup competition director John Darby and his expert team of inspectors. These same officials will serve as referees during the race, keeping a close watch on the cars as they return from the track. This article will explain both the pre-race and post-race inspection procedures, as well as highlight examples of cars that fail to meet the standards.

What happens if a car fails inspection? Could a winning driver lose their trophy if NASCAR discovers a problem after the race? The answers to these questions and more will be revealed. Let's start with the pre-race inspection process in the next section.

Out With the Old, In With the Car of Tomorrow

Bill France Sr. founded NASCAR more than 50 years ago with the vision of creating a racing series based on stock cars – the kind of vehicles you could drive straight from a dealership. Over the decades, technological advances and research have transformed the sport, but the original philosophy has remained intact. NASCAR's rules continue to require that the cars fielded by teams resemble those sold by manufacturers in showrooms.

With the introduction of NASCAR’s 'Car of Tomorrow' (COT), Sprint Cup cars underwent a complete redesign, losing the distinctiveness that past cars had. This shift led to changes in the inspection process to accommodate these new cars. NASCAR's goal is to ensure all cars are as evenly matched as possible. Previously, each manufacturer provided teams with vehicles that differed in specifications, leading to various measuring devices or templates being used to inspect different parts of the car. Issues like aerodynamic inconsistencies prompted teams from certain manufacturers to request adjustments to make the competition more balanced. The 'Car of Tomorrow' is intended to be uniform across the board for all competitors, with only the manufacturer’s decals setting them apart.

The inspection process begins at the NASCAR Research and Development Center in Concord, North Carolina. Teams construct chassis within a consistent set of specifications, regardless of the manufacturer. Each chassis is measured using advanced computers and robotic measuring arms to ensure all tolerances and specifications are met. Once NASCAR confirms the chassis adheres to the requirements, small radio frequency identification (RFID) chips are placed in strategic locations, and a VIN-like approval sticker is affixed to the chassis for future scanning.

As you’ll see in the next section, NASCAR has tightened its grip on the inspection process. Officials continue to clamp down on teams that attempt to skirt the rules in an effort to give every team a fair shot at success. Flip to the next page to find out how each car is inspected at the track before every race.

Initial Inspection

Before the crowd of race fans arrives at the track, NASCAR officials are already hard at work, meticulously reviewing each car with high-tech tools. They use specialized templates to verify if each car meets the exact specifications.

Now that NASCAR exclusively uses the 'Car of Tomorrow' (COT) in competition, a single, comprehensive template is employed for inspections. Previously, several templates were used to measure various areas of the cars, but with the COT, NASCAR uses a single, large template made of 19 individual templates welded together, covering the entire car. Known in the industry as 'the claw,' this template measures every aspect of the car. Similar to mass-produced vehicles, each stock car must conform to the claw’s tolerances. Officials check every specified point and look for any deviations. If a car doesn’t pass, the team is allowed to return it to the garage for adjustments. However, penalties can be levied if the car is found out of specification, and they often come after the race. In some cases, NASCAR may impound the car, forcing the team to use a backup vehicle.

NASCAR looks for signs that teams may have altered the sheet metal or ride height to gain an aerodynamic edge. The claw template is specifically designed to detect these modifications. During mechanical inspections, officials check the fuel tank, engine, and suspension to ensure the car meets NASCAR’s precise specifications. NASCAR's rules are explicit about engine size, fuel tank capacity, and suspension settings — everything must comply with what is permitted.

A new feature with the COT is the addition of a rear wing. If you’ve watched a Sprint Cup race, you might have noticed that all the wings are black, despite the colorful designs on the cars. This is because NASCAR prohibits teams from painting or placing decals on the rear wing. NASCAR is also extremely strict about the wing's dimensions. Every race weekend, NASCAR provides each team with a designated wing. However, teams still have the freedom to install the brackets that hold the wing, which leaves room for potential adjustments to the wing's height.

Restrictor plates, which limit air flow by covering the air intake, are only used at the Talladega and Daytona superspeedways, and NASCAR distributes these plates. Officials supervise as the plates are placed on the manifold, and the carburetor is bolted on top of the engine. To date, no team has been caught or accused of tampering with a restrictor plate, as doing so would result in severe penalties.

Once the initial inspection is finished, teams are cleared to practice and qualify. However, the inspection process doesn’t end there. In fact, it has only just begun. NASCAR officials still have two full days of work ahead, and teams have ample time to make adjustments to their cars, if they choose to do so.

Let’s move on to race day and see what happens before and during the race. This is where you’ll see that an inspector’s duties aren’t over until the last car hauler leaves for the shop.

Pre-race Inspection and Officials During the Race

Once teams qualify, NASCAR conducts a post-qualifying inspection to check key areas like fuel tanks and suspension systems. Teams often have engineers who develop adjustable shocks that change during the qualifying run. On occasion, cars are found with a low front or a high rear. A lower front end increases downforce on the nose, providing better grip in the turns, while a high rear end improves rear tire grip by allowing the rear wing to catch more air. Fuel tanks are also closely scrutinized to ensure they conform to the required fuel cell capacity. Even a gallon more of fuel could make the difference between victory and running out of fuel before the race ends. Fuel strategy is a major aspect of race day. To learn more about NASCAR’s fuel strategies and the technique of hypermiling, check out this article.

On race day, teams must once again take their cars through the inspection process. As mentioned earlier, each team submits their car(s) for a final check before the race begins. This inspection isn’t as detailed as the initial one, but officials are still vigilant, especially when it comes to the rear wing. Inspectors use gauges to measure the tolerance between the template and the hood. If the gauge doesn’t pass smoothly, the hood is too high and adjustments are made. That’s why teams bring rubber mallets to the inspection area to make quick fixes.

Once the cars pass through the inspection line, they return to the front of the garage and head to the shock station. Here, teams charge their shocks with the required pressure. Under the vigilant supervision of NASCAR inspectors, the teams install their shocks, getting the cars ready for action.

You might think an inspector's job is done once the cars pass the inspection lines, and it’s time for them to relax and watch the race. But that’s not quite the case. While inspectors do get to watch the race, they do so from the team’s pit box. Their work doesn’t stop during the four to six hours of the race. As NASCAR officials, they serve as referees throughout the event. Each inspector is assigned a specific driver and ensures the teams follow all NASCAR rules during the race. This includes keeping a close eye on pit stops, making sure every lug nut is properly secured, and monitoring crew actions. Inspectors make critical judgment calls during every race, with penalties for infractions ranging from time penalties to more severe consequences, depending on the violation.

Even after the race concludes, NASCAR officials still have important duties to fulfill. They are responsible for conducting the post-race inspection. Typically, the top five finishing cars undergo a final inspection where their measurements are rechecked. This is often where significant violations are discovered. In the next section, we’ll dive into the details of this crucial final step of the inspection process and explore how penalties can impact a team's standing in the point rankings.

­

Post-race Inspection and Penalties

During a post-race inspection, NASCAR focuses on several key areas. The primary concern is checking the height of the rear wing. NASCAR is generally lenient during these inspections, taking into account possible race damage that could affect the car’s measurements. There is typically a tolerance range within which the car must fall. Inspectors measure both the rear wing and front splitter height from the ground. If the car falls outside the accepted range, it faces penalties for the infraction.

Occasionally, NASCAR randomly selects race engines for testing on a dynamometer. This process takes place at the Research and Development Center in Concord. While most teams don’t worry about these inspections, sometimes they raise red flags. The primary focus of these dyno tests is to assess the engine's horsepower output.

Infractions do surface now and then during post-race inspections. Sometimes, these violations are attributed to racing damage, while other times NASCAR sees them as intentional attempts to break the rules. One of the challenges with NASCAR regulations is determining intent. NASCAR has to make a judgment call on each situation and apply penalties accordingly. With the introduction of the car of tomorrow (COT) and an overhaul of the inspection process, NASCAR has been able to refine its approach to infractions and penalties.

NASCAR generally waits until the Tuesday following a race to issue penalties. As mentioned earlier, Hendrick Motorsports experienced firsthand how strictly NASCAR enforces penalties for teams found guilty of violating rules related to the COT. NASCAR maintains a near zero-tolerance stance, with penalties that are often harsh. Crew chiefs and other team members have even lost their jobs as a result. In 2007, Michael Waltrip Racing dismissed the crew chief for the #55 Toyota after NASCAR found an illegal substance in the fuel system. More recently, Red Bull Racing fired the team members responsible for illegal sheet metal found on Brian Vickers' #83 Toyota.

Since the introduction of the COT, penalties have become more severe, impacting both the drivers—who face point deductions—and the teams, which incur fines, some as high as $150,000.