CONCORD, N.C — If you saw it, you'll never forget it.

That could apply to Robert Hunt being poured into a race car, all 323-ish pounds of him, perhaps the largest person to ever go through the window.

Or the faces of guys who just went faster than they've ever been on four wheels after whipping around the track at 185 mph.

Or maybe it was the look on Bryce Young's face when a grown man took off his shirt to show him his Alabama tattoo.

But maybe it was the man quickly wiping up a tiny spill off a concrete parking place as soon as he saw it. Or maybe it was the eat-off-them-clean floors in the garage or the precision machine tools shaving half of a thousandth of an inch out of an engine block cylinder.

Or maybe it was the banner on the wall proclaiming Hendrick Motorsports' 14 championships.

Whatever it was, the Panthers couldn't help but get the message this week when they took a day off from football practice to check out the top team in NASCAR's headquarters and then take a few laps for themselves at Charlotte Motor Speedway.

"It was so cool because I didn't have to say anything," Panthers head coach Dave Canales said. "Jeff Gordon got up there, he talked about the culture, he talked about people treating each other with respect. He talked about just enjoying coming to work with everybody and how many people are involved. Appreciating and having gratitude for all the hands that are involved, the communication, the precision, and all the things that we harp on.

"I didn't have to say anything. I'm just like guys, you heard it. Here's the guy; this is the legend saying it. Don't take it from me, take it from him. Just to be able to feel that."

There was a constant measure of awe, just walking through the high-tech facilities. But there was also the fact that these guys win at a rate no one else does. Every time a Hendrick team wins a cup race, they put another H on the wall. There are 307 of them now, and they had to renovate the building because the first wall that held Hs wasn't big enough.

"Yeah, it was cool," Canales said of the very visible reminder.

Gordon (who put 93 of those Hs on the wall and four of the championships) welcomed the Panthers when they arrived at Hendrick headquarters Wednesday morning and gave them a message that resonated with Canales and everyone who plays a team sport.

"As long as we do our job and stick together within these walls, nothing can touch us," Gordon said, describing the ethos of the Hendrick team and the secret of their success. He talked about culture in the same way Canales does.

Of course, the evidence was all around the Panthers players and coaches, and it wasn't hard to notice as the players made their way through the facility.

Since players are geared to compete, there was a chance at that, as they learned how the pit crew operates at the team's training center. Each day, the Hendrick pit crews drill there, trying to find the fractions of a second that can make a difference on race day (they've changed four tires in 8.5 seconds at a race, though they can often do it closer to 8.0 in practice). So, their crews gave the football players and coaches a quick tutorial and gave them a chance to try for themselves.

The football analogies were there, as the jackman is usually one of the big guys, and the tire carriers and changers are usually smaller and quicker. (The Hendrick facility is full of former college athletes, as they put their guys through a combine of their own when they're looking for crew members.)

But as the players were taking their turns in the pits, there were constant reminders of why these guys have had success.

Jacob Claborn, the head pit coach for Hendrick, gave instructions and let the Panthers get a practice run out of the way. Results were mixed on the first attempt, with some of them needing more than 30 seconds to change two right-side tires.

"This is the time that matters," Claborn told them before their second attempts. "You can have a bad day, and you can still win a race with a good pit stop late. ... "This is the money stop."

As he spoke and players locked in on their next try, another staffer noticed a spot on the floor of their pit stall and quickly raced over with a can of de-greaser and a rag and sprayed and wiped up the residue. There's a chance no one would have noticed it, or ever slipped there, costing a moment during practice. But you don't leave things to chance when the standard is so high.

On their second stop, Young's team — the quarterback was a carrier, along with Trevin Wallace, with changers Dane Jackson and Shy Tuttle and jackman Ikem Ekwonu — took their time from 26:02 to 15.50 seconds, the kind of improvement their coach wanted to see. The Hendrick crews also weren't above some playful trash talk, one of many similarities to what the Panthers experience on a day-to-day basis.

"I appreciate you, because I'm drained right now," safety Nick Scott told his instructor. Running back Chuba Hubbard admitted he wasn't expecting it (though sprinting around with power tools or jacks or 43-pound tires can definitely take it out of you). "I am drenched," Hubbard said after his second stop, though the Canadian crew chief did lead his team to the quickest time of his group. "I didn't know I had it in me, but I had it in me."

The competitiveness carried through the entire day, as Hunt's team (the free agent guard was joined by Chandler Zavala, Dicaprio Bootle, Jackson Mitchell, and Jeremiah Crawford) won the prizes for fastest stop, changing right sides in 13.06 seconds.

But the players also got to look behind the scenes at how the machines move even faster than the pit crews.

Walking through their engine facilities, players marveled at the precision machines used to mill the aluminum and titanium parts down to the smallest margins. "This is not like the lathe in my high school shop class," punter Johnny Hekker deadpanned as he watched the mammoth machine tools.

Players got a chance to see how the 500-pound, $100,000 engines were built, as well as making a lap through the shop, where bodies are put on cars, and lasers measure them to NASCAR specifications, and the engineers push that thin line between innovation and the rules.

They got a chance to see the control room, where engineers who don't travel to the track help the effort by scanning incredible amounts of data, grinding numbers on everything from pit stops to telemetry to gas mileage, and listening in to the rest of the field's communication (in NASCAR, you can hear every team on the scanner, which means if you commit to the effort, you can determine tendencies of crew chiefs and drivers and spotters). Long snapper JJ Jansen and quarterback Andy Dalton stayed behind — and could have stayed all day — peppering director of competition systems Alba Colon with technical questions.

As much as the players would have liked to record it, they weren't allowed to pull out their phones for photos in certain areas, because of the proprietary information and equipment all over the place. But one Hendrick staffer did grab his phone when the Panthers walked through.

Greg Campbell — they call him Otis — is from Hueytown, Ala., the home of the famed Allison racing family ("I grew up with Davey," Campbell said of the late NASCAR star). He hangs bodies on cars, but he's a big Crimson Tide fan, too, and has the ink to prove it. After one of his co-workers snapped his pic with the former Alabama quarterback, he encouraged Campbell to show Young his tattoo. This is a thing that happens from time to time, but everyone was a little surprised when Campbell unbuttoned his Hendrick work shirt (everyone there wears the uniform) to show Young the huge A logo with the elephant that was inked into his back.

"Noooooo, don't do it, Otis," Campbell's co-workers in the garage laughed, but he did it anyway as Young grinned and approved of the art.

Believe it or not, that wasn't the most impressive thing they saw all day.

The next stop on their tour was team owner Rick Hendrick's private collection of cars and memorabilia, which extends the same kind of precision and detail as the rest of the place. The Jimi Hendrix guitar is in the back left corner of the room, a signed Taylor Swift model is in the glass-covered case under your feet when you walk up the stairs made of truck bumpers and into the second-floor room.

There were multi-million-dollar machines throughout the building — everything from Transformers to fire trucks to the old police car that used to give Hendrick tickets growing up in Palmer Springs, Va. But Hendrick is a Chevrolet guy at heart, and the tour guides inform the players there are 105 Corvettes on the floor (not a lot, or not around 100, but precisely 105). There's also a conference table made out of an old Corvette chassis ("If you put fluids and a battery in it, you could crank it," the tour guide said), along with a parade of rare Ferraris and other luxury cars, and plenty of new models with VIN number 1.

It was a lot to take in, but the theme was clear.

As a group of Panthers players took the stage at lunch with the Hendrick staff in the team center, they expressed their thanks at being able to take it all in.

"This proves to us what culture really means," wide receiver Adam Thielen said. "The culture here is different; that's why all those Hs are up there on the wall."

After lunch, they got a chance to put their new expertise into action with a quick ride over to Charlotte Motor Speedway for a few laps at the NASCAR Racing Experience.

Once players were fitted with protective gear and helmets, they slid into the passenger side of actual race cars for three laps around the 1.5-mile track.

It was easier for some than others.

Hunt is the largest person among a group of large people, and there was some debate about whether he was going to get into the car. These things don't have doors, and it's hard to imagine getting Hunt through a 17-inch-high window.

But with some effort, he was able to wriggle in.

"It looks like a reverse birthing," one of his coaches said as he watched Hunt go in.

"It was fun. It was an experience. I'm glad I did it," Hunt said after he took his laps (getting out was easier than in). "Would I do it again? Maybe not, but I did it today. I was pretty nervous, and the car was all crammed on me. So I'm like, God, please let me get through these couple of laps to get done, man. But I enjoyed the ride.

"The car was a little cramped on my back, and there wasn't a lot of room to move my legs, but we got through it. Yeah, it ain't meant for me, man. I'm meant to be on the football field, or a basketball court, you know what I mean? Something outside where I can move, and you know, get some space. I can't do nothing in there, man. It's too little."

Others were more enthusiastic despite the space constraints.

Center Austin Corbett is merely huge at 305 pounds, but after crawling out of the car, all you could see was grin.

"That was awesome," Corbett said. "I want to drive it now."

Canales joked that other than some teenaged speeding tickets growing up in Los Angeles — "the speed limit's 65, but everybody's doing 80-something on the freeway," he said — nothing he's done has approached what he did Wednesday afternoon, even if he couldn't tell how fast he was going.

"All I know is he had his foot all the way down on the straightaway, we hit the turns, and I felt both my lungs swung to the right of my chest cavity," Canales said. "It was shaking. It was awesome. I could feel the Gs coming around, and then we got pretty close to the wall, too. I think we were probably about 6 inches from the wall before we came back down."

A few of them even got to take their laps in a familiar-looking ride, as vice president of player affairs Kevin Winston ordered up a special wrap for one of the cars, turning it black and blue with a number 51, and Sam Mills' Keep Pounding mantra. (The sponsor stickers on the front fender were nods to members of the team's Hall of Honor, because detail is everything). That car will remain part of the NASCAR Racing Experience stable for the rest of the year.

But for all the new experiences, Canales kept coming back to seeing the best in another sport at the Hendrick facility and bringing that feeling home with him. That was the point of the trip.

"I mean, everything there is so detailed and precise and clean," Canales said of the morning with the top team in another sport. "How you do anything is how you do everything. You didn't go anywhere where there wasn't people there ready to receive you and treat you like their own.

"That's how you do it, so it was great for us to see."