In 1974, he joined IMSA, now the American Le Mans Series, and competed in the series until 2003. During that time, he got to race at some of racing’s premier facilities, Daytona, Le Mans and Sebring. He won the 2001 24 Hours of Daytona in class (SR). He also two other top-three finishes at Daytona.
He competed in the 24 Hours of Le Mans in 1995, 1996 and 1997, with a car he built. In 1995, he finished seventh overall.
He won five championships with IMSA during his career.
In 2002, he won the Phil Hill Award, which is annually presented to the most outstanding driver, entrant or outstanding member of the Road Racing Drivers Club. Past winners include Juan Manuel Fangio II (1994), Danny Sullivan (1997), Bill France (2001), Skip Barber (2007) and Roger Penske (2008).
In 2008, Downing received the Bob Akin Memorial Motorsports Award, and in 2012 was inducted into the Sebring Hall of Fame.
“I race because I like racing,” he said. “I just kept at it.”
After his IMSA career, he went back to sports car and club racing because, “it’s where I started.”
“Then I was at the age racing in 60s and early 70s and I’m 71 and you don’t get sponsors when you’re 71,” he added. “You have to sponsor yourself.”
In addition to having competed at the first Runoffs, Downing has also competed at each track that hosted a Runoffs.
“Road Atlanta is probably my favorite,” Downing said.
Downing didn’t have a grand scheme when he was finally eligible to race.
“My goal was to just make the next race,” he said.
When he turned 21, he was a full-time student at Georgia Tech where he was studying industrial management. Racing and girls, in no particular order, were his interests.
“I didn’t try to be a Formula 1 driver,” he said. “I never even thought about pro racing quite frankly. I was enjoying club racing.”
When the IMSA opportunity came up, he believed he was ready.
“I just wanted to get better,” he recalled.
Once with IMSA, it was a big learning curve and ultimately one that made him into a better driver than he’d ever imagined. He was racing more than 50 cars at once. What he learned competing with IMSA in a short of period of time would’ve likely taken him years to learn had he stuck with pro or club racing. And that is if he would’ve ever learned it.
“It changes your outlook on things,” he said. “I was very lucky to get hooked up with Mazda.”
Mazda sponsored him throughout his IMSA career. To this day, he still maintains that he doesn’t have a plan for tomorrow regarding his racing career.
“People will say, ‘Well, what’s next Jim?’ And I said, ‘I’m happy with what I’m doing,'” he said. “I’m doing well. I’m winning races and making a little money.”
“I was extremely lucky,” he added. “To be able to do this for 51 years is ridiculous.”
Downing contacted John Bishop in 1974 looking for a new challenge. Bishop created IMSA.
“He just gave me a great sales pitch,” Downing recalled. “I sent him my $60 membership fee and he said, ‘And Jim, you will get your entry fee back at every race.'”
Downing was convinced.
“That’s unheard of in club racing,” he said with a smile. “That was a big deal.”
That was the first time in his life Downing realized you can make money racing. That was enough incentive to go to the next race.