Following Friday’s lone 50-minute practice session at Phoenix Raceway, NASCAR inspectors confiscated the hood louvers off all four Hendrick Motorsports cars – the No. 5 of Kyle Larson, the No. 9 of Josh Berry, the No. 24 of William Byron and the No. 48 of Alex Bowman.
Hood louvers are vents in the hood on each manufacturer’s car that serve as a release point for ducts that transfer air out of the radiator.
The use of vents prevents the need of teams’ to tape up the front grille of car, which had been used extensively as a performance adjustment tool in the previous iteration of race car.
Louvers are considered a single-source supplied part on the Next Gen car and NASCAR has issued severe penalties for alterations to those parts in the past year.
Such penalties have included up to 100 points, 10 playoff points and a four-race suspension for a team’s crew chief.
NASCAR will take the Hendrick louvers back to its research and development center in Concord, N.C., for further evaluation. Any penalties will be announced early next week.
NASCAR officials first noticed an issue with the louvers during initial inspection Friday but allowed the teams to utilize them during practice and they were then confiscated.
The teams were allowed to change the louvers prior to Saturday’s qualifying session.
Larson ended up fastest in Friday’s practice session and Bowman third. Byron was 20th and Berry 23rd.
Larson went to win pole position for Sunday's race. Byron will start 3rd, Berry 17th, and Bowman 18th.
Kaulig louvers confiscated
Following Saturday's qualifying session, NASCAR announced it had also confiscated the hood louvers from Kaulig Racing's No. 31 Chevrolet driven by Justin Haley.
Those louvers were taken prior to the start of qualifying and the team was allowed to replace them and take part in time trials.
As with the Hendrick parts, the No. 31 louvers will be taken to the R&D Center for further evaluation and any penalties announced next week.