Auto racing's biggest day became a Memorial Day weekend tribute to NASCAR racing great Kyle Busch from Indianapolis to Charlotte Motor Speedway.Busch died Thursday at 41 after severe pneumonia progressed into sepsis, resulting in rapid and overwhelming complications, according to a statement released by his family, and his loss sent shockwaves through the motorsports world and beyond.Video above: Racing community 'stunned and saddened' by death of Kyle BuschAt the Coca-Cola 600 — a race Busch won in 2018 — NASCAR and Charlotte Motor Speedway honored the two-time Cup Series champion with a large, black No. 8 and his signature on the frontstretch grass and a photo on the videoboard.The U.S. Army Golden Knights planned to carry Busch's flag prior to pre-race festivities following a moment of silence. Each of the 39 cars in the field will carry Busch's decal. And, the speedway's public address system and the television commentators plan to go silent on the eighth lap of the race.There may be other undisclosed tributes planned as well, per track officials.On Saturday night, Layne Riggs celebrated his Trucks Series win at CMS by doing one of Busch's traditional bows to the crowd after the race, and Ross Chastain did the same after capturing the rain-shortened O'Reilly Auto Parts race. "When you think race car driver and what that person should be like, Kyle Busch is probably one of the first that comes to your mind on the type of racer he was," Cup Series driver Joey Logano said.Fans at CMS arrived in droves with shirts to honor Busch that read "Rowdy" and "KFB."Video below: Released 911 call sheds light on Kyle Busch’s medical emergency hours before deathEarlier in the day at the Indianapolis 500, Dale Coyne Racing changed the font of Romain Grosjean's No. 18 car to replicate the font the two-time NASCAR Cup Series champion and two-time Brickyard 400 winner used during his 14 seasons with Joe Gibbs Racing in his No. 18 car.Then came the opening prayer, in which Busch was mentioned by name. And on Lap 18, race officials lit up the scoring pylon next to pit lane with Busch's name, his birth year and 2026.Even with the pageantry of Indianapolis' big IndyCar race, Busch, who had a record 234 victories across NASCAR's three national series, was never far from the thoughts of people in the city that dubs itself the "Racing Capital of the World." The father of two died Thursday at age 41 from what his family said was severe pneumonia that progressed into sepsis."It's desperately sad. It's also one of those things where you try not to think about it or let it in because you've got so much to do, you can't let yourself get emotional," Katherine Legge said Friday after returning to Indianapolis Motor Speedway. "But honestly, racing has lost one of the greatest drivers, in my opinion, of all time. If you look back at the history and just — he was a legend."As Indy held its biggest race of the year, those who knew or competed against Busch raced with a heavy heart."How can you not be in shock over the situation?" two-time Indy winner Josef Newgarden said Friday. "I think it just puts into perspective how fragile life is. You just don't know. Makes me think of his kids, to be honest with you. Gosh, I feel terrible about — I have two sons now. That's the thing that breaks my heart."Richard Childress Racing announced it would suspend using Busch's No. 8. The car will now compete as No. 33. It was driven by Austin Hill in Sunday's race.Busch was instrumental in the creation of RCR's stylized No. 8. Over the years, it became synonymous with his legacy, his fans, and the sport of NASCAR itself.Out of respect for everything Busch meant to Richard Childress Racing and NASCAR, No. 8 will remain reserved for Busch's son, Brexton, if he decides to pursue a NASCAR career.Fans from around the country paid tribute to the late driver on Sunday.Disbelief, shock, surprise — that’s what a lot of motorsports fans are feeling afterBusch suddenly died, just days before he was set to hit the track in Charlotte for the Coca-Cola 600.Benjamin and his mother, Rhonda Whitley, are now reflecting on the time they got to meet their hero in person."I was just speechless," Benjamin said. "There's really no words to say. Basically, he was very social, he posed for pictures, etc. He was very nice.""It was like we met a new friend," Rhonda said. "He was just like, I don't know, we felt like we were friends with him. I cried more than I've ever cried for somebody that I really didn't know. We've met different friends through him. I mean, he brought us together with different people."James Saxton feels the same. When he had the chance to meet Busch, what instantly stuck out to him was the NASCAR legend’s authenticity."I've seen him win out in New Hampshire multiple times, and I actually got to meet him a couple years, just under two years ago, out at the local short track in New Hampshire," he said. "I was able to shake his hand, say hi, get a couple of things signed by him. He's just real, you know, what you see on the track and away from the track, it's just, it's who he is."All three say when it comes to motorsports, Busch will forever be known as one of the greats.Hearst sister station WXII contributed to this report