NASCAR's Hendrick Motorsports fined record $400,000 for making modifications to cars

March 15 (UPI) -- NASCAR announced a record penalty against Hendrick Motorsports on Wednesday, fining the team $400,000 for making prohibited modifications to its cars.

Each of Hendrick Motorsports' four NASCAR Cup Series teams is being fined $100,000 after the teams were discovered to have made illegal modifications to the hood louvers of five cars that competed in Sunday's race at the Phoenix Raceway.

The drivers of the violating race teams were Kyle Larson, Josh Berry, William Byron, and Alex Bowman. Justin Haley's team from Kaulig Racing is also being fined. Byron won the race after taking and holding an overtime lead. He led from the outset of the race before being passed by Larson after 60 laps.

The crew chiefs of these teams -- Cliff Daniels, Alan Gustafson, Rudy Fugle, and Blake Harris, along with Kaulig's Trent Owens -- will be fined and suspended for four races. Each team will also be docked 100 points, as well as 10 driver points.

The role of hood louvers is to ventilate hot air out of the engine bay to keep the engine from overheating. The modifications in question are related to how the radiator duct is assembled, CBS reports.

"We, from time to time, will capture parts, we'll bring them back," Elton Sawyer, NASCAR's senior vice president, said in a statement on Wednesday.

"And as we continue to investigate and look at parts and comparing parts, it was obvious to us that these parts had been modified in an area that wasn't approved."

Hendrick Motorsports announced it plans to appeal the penalty.

"On Friday at Phoenix Raceway, NASCAR identified louvers on our race cars during a voluntary inspection 35 minutes after the opening of the garage and prior to on-track activity," the statement from Hendrick Motorsports said.

"NASCAR took possession of the parts approximately four hours later with no prior communication. The situation had no bearing on Saturday's qualifying session or Sunday's race."