How does NASCAR ensure engines comply with horsepower limits? Explained

NASCAR engines are designed to deliver high speed on the tracks, but to keep the game safe for drivers, the sport's governing body enforces strict rules and regulations for engines. To comply with the horsepower limits, manufacturers use devices like restrictor plates and tapered spacers.

Stock car racing engines adhere to a strict 5.86-liter (358 cubic inch) displacement limit, maintaining the traditional V8 configuration with eight cylinders. Modern-era engines are designed to produce up to 670 horsepower, utilizing an iron block to prioritize durability and power. Teams must carefully balance power output with reliability, ensuring none exceed the horsepower limit.

NASCAR ensures a level playing field by using restrictor plates, a method that has been used for a long time. These plates limit the flow of air to the engine, reducing the power and controlling the speed of the car on specific race tracks such as Daytona and Talladega Superspeedways. On these tracks, the engines are limited to 510 horsepower for safety purposes.

Recently, the governing body started using tapered spacers over restrictor plates. Tapered spacers are similar to restrictor plates but allow more precise control over engine horsepower and torque. Additionally, the Stock Car Racing Association conducts pre- and post-race inspections to keep the game fair, and failing the inspection can lead to severe penalties.

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NASCAR announced major changes in the qualifying format for the 2025 season

The Stock Car Racing Association has revised its qualifying and practice format for the Cup, Xfinity, and Craftsman Series for the 2025 season. The officials have increased the practice session time to 50 minutes and reduced the qualifying to a single-lap session.

However, Superspeedway tracks, including Daytona, Talladega, and Atlanta, will have two-round qualifying sessions. The top ten drivers of round one will advance to the second round to secure the pole position. The governing body has also introduced a 50-minute practice session for the Daytona 500 before the qualifying session ahead of the 2025 season.

Fox Sports renowned reporter Bob Pockrass shared detailed information about the decision through an X post. He wrote:

"Qualifying in 2025 (all series): Only two rounds at superspeedways, where top-10 go to final round. The rest will be one round. Road courses will be split in two groups, 20 minutes each group. Order by metric: 70% previous race finish of car; 30% owner pts."

NASCAR will begin the 2025 season with the inaugural point-paying race at Daytona International Speedway on February 16, 2025.

Before the Daytona race, the Stock Car Racing Association will host a race at the historic Bowman Gray Stadium on February 2, 2025. NASCAR is returning to the track after a long hiatus of 51 years.