On Friday, current NASCAR Cup Series champion Kyle Busch got his first taste of modern sports car racing when he took his initial laps in the No. 14 AIM Vasser Sullivan Lexus RC-F GT3 in the opening session of the Roar Before the Rolex 24.

As the three-day IMSA WeatherTech SportsCar Championship weekend drew to a close on Sunday, Busch was happy with the learning experience as he prepares to race the front-running GTD car he will co-drive with Jack Hawksworth, Parker Chase and Michael De Quesada.

“I’m certainly learning a bunch, getting a good feel for the track and traffic,” Busch said. “I’m pretty confident with everything we’ve got going on. There are a few little tiny things to change, but sometimes those little things can mean a big deal.”

The biggest adjustment for Busch has been with his braking technique, which is very different in the nimble GTD Lexus compared to the heavier Toyota Camry he races in NASCAR.

“It’s just getting used to the brakes, how hard you can abuse them,” Busch said. “This car has ABS, and it’s a different system of being able to push the car to its limits. It takes care of itself, getting into the corners, and I’ve certainly overstepped that a couple of times trying to find out where that limit is.

“I’ve been able to fine tune where I need to be, and that’s been getting more consistent each run out,” he continued. “I’ve been able to bring my lap times down, and get a little bit quicker. I’ve been working on the ability to keep the rear tires on for the entire run, and not getting too out of shape.”

Another transition is running in the slower but hotly competitive GTD class, which features close racing against fellow class contenders while keeping an eye out for the faster GTLM, LMP2 and especially DPi cars.

“One time I was all ready to pass another GTD car but I was told there was a DP car coming,” Busch said. “I had to stay in line and forfeit the next corner; and then I had to wait all the way until Turn 1 to get by. Moments like that are going to play out the whole time. You could be faster than another guy, but you have to be aware that there are other guys coming that can blow your doors off. And you can lose a lot of time doing those things. But if comes down to the final four hours, I imagine Jack will be driving so it will be his responsibility.”

Running at night presented no special challenge for Busch, who turned several laps during the Saturday evening session.

“I had no problems at all,” he said. “There’s plenty of lighting out there. They asked me if I wanted the headlights tuned so I could see better, but I said, ‘What do you even need the headlights for?’ I’ve raced local short tracks coming up as a kid where there wasn’t much lighting.”

As a footnote, he might have a different opinion of night racing if he someday gets the opportunity to tackle Sebring or Road Atlanta…

Busch also is learning a different philosophy in driver etiquette. While sports car drivers shy away from the nose-to-tail contact that’s not uncommon in stock cars, side-to-side contact is more prevalent in this form of competition.

“I’ve learned from Jack that correct road course driver etiquette is never to be on the outside of another guy because he will just force you off,” Busch said. “He was actually entertained when he ran his NASCAR race at Road America last year that that guys would give you room on the outside of a corner without throwing you off. Here, you can’t really touch front to rear, but they’ll body slam you if they need to.”

After his first experience in the car, Busch is eager to actually racing the No. 14 Lexus.

“It’s been fun, and I’ve certainly enjoyed it. I look forward to coming back for the Rolex 24.”