Loomis's first professional crew chief position came with Petty Enterprises in 1990, when he replaced Dale Inman as Richard Petty's crew chief. He worked with Petty Enterprises as crew chief for 9 years. As an underdog at Petty Enterprises, Loomis managed to lead the famed #43 car to the winner's circle three times. He won in 1996 and in 1997 with Bobby Hamilton. John Andretti piloted the car to victory lane in 1999. In 2000, Loomis earned the honor to work at Hendrick Motorsports as Jeff Gordon's crew chief and prior to that he had not received a check from anyone other than Petty Enterprises. The Pettys supported Loomis's departure. In Jeff Gordon's autobiography, Richard Petty is quoted as telling Loomis the following:
I took it for granted that you'd always be around. Now, if you were talking to me about ninety-nine percent of the deals you could possibly have, I'd tell you to get out of here and get back to work. But Rick Hendrick is good people.
This is a real good opportunity for you. Jeff's a winner. It wouldn't matter if he was playing golf or baseball or hockey or driving a racecar, he's a winner. Winners are gonna win, and they're gonna breed winners. You're looking for something Jeff and I have already found. We've won races. We've won championships. That's what you're searching for. I've always told you that what you needed was a twenty-five year old Richard Petty. I think you've got that in Jeff.
Crew chief for the #24 Hendrick Motorsports team
Robbie Loomis's greatest success came as crew chief for NASCAR legend Jeff Gordon. The pair's first season in 2000 was a struggle. Despite winning 3 races and finishing 9th in the season standings, performance was well-short of the high standards set by the #24 Hendrick Motorsports team. However, in the final 5 races of the year, the team posted 5 top-10s and 3 top-5s: a clear indication of the improving communication between Loomis and Gordon. The momentum carried into 2001 and the #24 team reached the pinnacle of the sport by winning the NASCAR Winston Cup Championship. In addition, the team won 6 races, including the prestigious Brickyard 400. The following years, in 2002 and 2003, the team performed respectably, ranking 4th in the standings and winning 3 races in both years, but their performance was not quite of the championship caliber expected from the #24 team. Loomis and the team almost returned to championship glory in 2004, but finished 3rd in NASCAR's first "Chase for the Championship" by a heartbreaking 16 points to winner Kurt Busch. They won 5 races that year, including another Brickyard 400, and also earned the most points of any team for the entire year. 2005 began in thrilling fashion as Loomis won his very first Daytona 500: NASCAR's crown jewel event. The #24 team also went on to win at Martinsville and Talladega early in the year, but the rest of the season would be a nightmare. The #24 team experienced radical handling problems at downforce tracks. After a 2nd-place finish at Darlington in the season's 10th event, the #24 team failed to produce another top-5 finish in the next 16 races under Loomis. The team shockingly missed NASCAR's "Chase for the Championship," and Loomis was replaced by 26-year-old Steve Letarte for the final 10 races to prepare the young crew chief for 2006. Loomis had been grooming Letarte, the team's car chief since 2002, to take over the position. Loomis had already planned on leaving the stressful job after 2005 due to a reorganization of priorities. Loomis's mother, Sallie, survived a serious pancreatic illness the previous year. In January 2012, Loomis was released of his duties as Chief Operating Officer for Richard Petty Motorsports.
Philanthropy
In addition to NASCAR, Loomis works on charitable projects. With his family, he founded The Robbie Loomis Foundation in 2002, which joined the NASCAR Foundation Family of Charities in 2007. The public, not-for-profit 501 foundation awards need-based grants and scholarships to students in grades K through 12.