When drivers take the green flag for Sunday’s Coca-Cola 600 at Charlotte Motor Speedway, it will be under daytime conditions at approximately 6:15 p.m. ET.
When NASCAR’s longest race ends some five hours later, nighttime will have long since fallen.
So what are the challenges that drivers and crew chiefs face in a marathon-style event that begins with the sun out but ends under a moonlit sky?
This much is certain: The task of excelling under virtually polar opposite track conditions requires being extremely nimble of terms of driving style and car setup.
“The track really changes a lot from day to night and that’s something that we really learned in the Coca-Cola 600 is how much the track changes when night falls,” said Wood Brothers Racing’s Ryan Blaney. “So your car can be either really good or really bad in the daytime and it can really change drastically at night, and that’s something you really have to be prepared for and try to get your car to be able to work well in both. That’s just something I’ve always noticed about this racetrack, whether I’m running an XFINITY car or a Cup car there. It always changes a lot when it cools down.”
Blaney actually prefers racing at Charlotte during the day, versus the night.
“I kind of like day races,” he said. “Nighttime looks really cool and everything and I love racing under the lights, but when it’s sunny outside and the track’s hot and slippery and you’re really sliding around, it makes it pretty difficult and a lot of fun and it makes the drivers have to search around a lot for grip.
“If it’s really gripped up at nighttime, everyone’s kind of married to the bottom and it’s kind of hard to go forward if you find yourself in the pack. So day races I feel like at Charlotte Motor Speedway puts on a little bit better racing because the track is slippery and drivers are always searching around for grip.”
Former Sprint Cup crew chief Drew Blickensderfer corroborates Blaney’s viewpoint.
“When the track has a lack of grip in it like it does during the day, different lanes come into play,” Blickensderfer said. “A lot of times during the fall there’s cool weather. With a night race there’s lots of grip in the racetrack so the shortest distance is where everybody’s running so everybody’s stuck on the bottom wanting to get around here as quick as possible. In the summer when the heat’s on the racetrack in the middle of the day, people will search up to the top, they’ll search to the bottom. Especially in turns 3 and 4 where there’s a lack of grip, you’ll see that.
“I think your game plan is for your driver to search for that in practice so he kind of knows what it’s going to take when they start losing grip on the bottom, because everybody’s running there, and if he can move up, what’s the balance change?”
What says driver Landon Cassill?
“If you’re really going to handle, you’ve got to be really meticulous about your line, especially in turns 3 and 4 because it just seems like the sun beats down on 3 and 4 so much during the day that if you miss your line in 3 and 4, you give up way more speed,” Cassill said. “If you miss your line by three feet in turn 3 and 4, you give up way more speed during the daytime than if you miss your line by three feet at night. So you just have to be way more meticulous and way more careful about hitting your marks, being consistent and repeating your line.”