Updated

Concord, NC (SportsNetwork.com) - The Sprint Cup Series will run its longest race of the season -- the Coca-Cola 600 -- this Sunday at Charlotte Motor Speedway.

When the series competed at Charlotte one year ago, Jimmie Johnson surpassed NASCAR Hall of Famers Bobby Allison and Darrell Waltrip for most wins at this 1.5-mile track with seven. It was also the fourth time Johnson scored a victory in the 600-mile race here.

Waltrip has the most wins in the 600-mile event with five.

Last year, Johnson had been winless in the first 11 races of the season before his victory at Charlotte. He started on the pole and led a race-high 164 laps, including the final nine.

Johnson, the driver of the No. 48 Hendrick Motorsports Chevrolet and six-time Sprint Cup champion, has already won three races this season. All of them have occurred on a mile-and-a-half track -- Atlanta, Texas and Kansas.

The NASCAR Sprint All-Star Race took place at Charlotte last Saturday. Johnson holds the record for most victories in that event with four, but he finished 15th in it this year. He's hoping for a better result in the Coca-Cola 600.

"It's always great to come to a track that you have a great past at, great history at," Johnson said. "Unfortunately, the showing we had in the all-star race was less than stellar. The confidence we would normally walk in with has been diluted with lack of speed that we had then.

"We brought back a different car and certainly trying to do things differently with the set-up of the racecar. I think the 600-mile race has always been good for us. (Crew chief) Chad (Knaus) and I seem to fix our race car as the night goes on, be aggressive with adjustments, chase the racetrack well and I do a nice job searching for line. The distance of the race doesn't bother me. I think we will have a strong night."

Earlier this week, Johnson's No. 48 team received a written warning from NASCAR for altering the side skirts on their car during the all-star race.

Prior to the start of the 2015 season, NASCAR made a rule modification that prohibited Sprint Cup teams from flaring the side skirts -- the sheet metal ahead of the rear tires on the car -- during pit stops in a race. It had the potential to improve air flow over the rear of the car, which would help increase speeds. The practice became widespread in Sprint Cup during the latter half of the 2014 season.

NASCAR will issue a warning to any team in their first offense of altering the side skirts and then assess penalties if there are repeat offenses.

"We were very shocked to even hear that there was an issue with the side skirts," Johnson said. "I think leaving the racetrack NASCAR was upset and thought there was a lot more intent and something going wrong with the side skirt being pulled out. Then as video became available and they looked through it and watched and saw what was done, it calmed down. We were shocked to hear there was an issue, and actually we had crash damage on the right-side of the car."

On Thursday night, Johnson qualified 13th for the Coca-Cola 600. Matt Kenseth claimed the pole position with a qualifying lap of 194.252 mph. Johnson was the highest finisher among the five Hendrick drivers in qualifying. Dale Earnhardt Jr. placed 15th, Jeff Gordon 18th, Chase Elliott 28th and Kasey Kahne 33rd.

Johnson won the 2003 rain-shortened Coca-Cola 600 after starting 37th. Last October, he started 21st and finished 17th in the 500-mile race here -- the fifth race in the Chase for the Sprint Cup championship.

"This track is tricky," he said. "It's tough to get it right. Luckily, it's a long race, and if need be in the race, we will make big changes."

Sprint Cup teams will practice for the Coca-Cola 600 on Saturday -- a 55- minute session in the morning and then a 50-minute session in the afternoon.

Series: NASCAR Sprint Cup. Date: Sunday, May 24. Race: Coca-Cola 600. Site: Charlotte Motor Speedway. Track: 1.5-mile oval. Start time: 6 p.m. ET. Laps: 400. Miles: 600. 2014 Winner: Jimmie Johnson. Television: FOX. Radio: Performance Racing Network (PRN)/SIRIUS NASCAR Radio.