NASCAR officials took the hood louvers from the four Hendrick Motorsports Chevrolets at Phoenix Raceway, and the sanctioning body will bring them to the NASCAR Research & Development Center for further evaluation next week in Concord, North Carolina.
During initial inspection Friday, league officials discovered a potential issue that needs further examination. Hendrick cars were permitted to use those louvers in practice, with officials taking them after the opening session at the 1-mile track.
RELATED: Full practice results
There is no penalty to Hendrick cars this weekend, and any potential penalties would be announced next week. The Hendrick organization can replace the hood louvers prior to inspection on Saturday and in advance of qualifying (2:05 p.m. ET, FS1).
The hood louvers – which you can see on this Next Gen 3D model – are openings or vents in the hood that serve as a release point for ducts that transfer air out of the radiator. The system is intended to decouple engine performance from aero performance, offsetting the practice of teams taping off air intakes and placing undue pressure and heat strain on the car’s engine.
Hendrick Motorsports driver Kyle Larson paced the field in practice Friday in the No. 5 Chevrolet, turning his fastest lap time at 131.258 mph (or 27.427 seconds). Alex Bowman was third overall in the No. 48 at 130.725 mph. Last week’s winner William Byron was 20th overall (129.241 mph) and Josh Berry, filling in for the injured Chase Elliott in the No. 9, was 23rd (128.986 mph).
Friday’s practice served as the debut for NASCAR’s new rule package featured on most short ovals and all road courses in 2023. The configuration includes a 2-inch spoiler and fewer strakes underneath the car, reducing downforce by approximately 30%.