NASHVILLE, TENN.—Cliff Daniels still isn’t getting much sleep, almost a month after he lay awake the entire night before leading Kyle Larson to NASCAR’s championship. Daniels is notoriously intense, as close as a clone as one can be to seven-time championship-winning crew chief Chad Knaus. But after clinching his first Cup Series title as crew chief with Larson’s win last month at Phoenix Raceway, Daniels revealed he struggled to sleep before every race this season. “My resting heart rate is too high. I have not slept before any Cup race all season long,” Daniels said. “Pick a random race in the middle of the year, I did not sleep. You can ask my wife, and, I promise you, all the time she lectures me, ‘You have to get sleep, you have to get sleep.’ But I cannot sleep because I hold myself to a really high standard, and I think …