Championship lead in hand, Aitken, Bamber and Action Express plan to finish IMSA season strong

For two days on the streets of downtown Detroit, the red No. 31 Cadillac Whelen V-Series.R was the fastest car in IMSA GTP from the moment it rolled out of its hauler on Thursday.

And after finally kicking down the door to its first win of the 2026 season, Action Express Racing, Jack Aitken and Earl Bamber are firmly in the drivers seat going into the second half of the WeatherTech SportsCar Championship.

“As soon as it hit the track, it was super-quick,” Bamber said after winning the Chevrolet Sports Car Classic. He put the No. 31 Cadillac on the pole on Friday – his first IMSA pole since the 2015 Petit Le Mans – and led the first 27 laps of Saturday’s race.

“We sort of built on what we had last year, we knew that it was good. And I managed to pull a gap [in the first stint], and just managing the energy,” the Kiwi recalled of his opening stint.

“We had a little bit of a tricky moment with the No. 23 [Aston Martin Valkyrie]. I think they had a drive-through or something like that; I don’t really know why they were near us. But we sort of started to get boxed behind them.”

Instead of getting stuck in traffic and risk losing their lead, the Cadillac Whelen team brought Bamber into the pits a bit ahead of schedule while they had a comfortable gap. “We were one of the only cars to also change right-hand side tires, and we were just making the job easier at the end of the race if the yellows came for Jack, which was the right call,” Bamber stated.

“Our team is great with the strategy at the moment. Whatever gets thrown to them, they know how to react. And the fact that we can take tires when no one else could just shows what they’re doing in the lane and on the strategy stuff. And then Jack just did a faultless drive to the end.

“I think that’s probably a pretty perfect weekend.”

Aitken retained the net lead after coming out of the pits with his two fresh right-side tires. He then led the final 46 laps (a combined 73 out of 82 laps led for the duo), but also had to nail down two late-race restarts when the final 20 minutes were peppered with yellow flags and incidents.

They were the headlining performers in a double victory for GM, right at the doorstep of their famous Renaissance Center complex. Cadillac won in GTP, and Corvette Racing won in GTD Pro for Chevrolet. It was GM’s first clean sweep of an IMSA race since the 2018 Grand Prix of Long Beach.

“I think it’s a win that we’ve been searching for for a while, since this program started,” remarked Aitken, the new GTP points leader. “With Detroit being the home for GM, for Cadillac, for so many of the people on the program, it was very meaningful.

“We’ve come close with podiums, but to get the win on the same day that the Corvettes managed to do the same – it’s pretty overwhelming, but amazing!

“Very grateful to have the team around me that I do. From Earl, who was just incredible with his pace this weekend and from his pole position, to handing me the car in the race in the lead, it made my life very easy, which was nice. But the car was very, very impressive as well. We had a very good car from the get-go. The Whelen Cadillac guys really nailed it.

“There was no cruising, because on a track like this, when you start to ease up, it can bite you in the a** quite quickly.”

In this perfect weekend, Aitken and Bamber led all but the third practice session on Saturday morning, which was a morning warm-up session in all but name.

Aitken leaves Detroit with a 144-point lead in the GTP drivers’ standings and only four more races left for IMSA’s premier class. Bamber’s FIA WEC commitments leave him out of a share of the drivers’ title, but he was beaming with pride to reward everyone at Cadillac, Action Express, and all their partners with such a victory.

“When we’ve got such an amazing car, it makes it a lot easier,” Bamber said.

“But there’s also just a huge amount of work going on behind the scenes. The simulator work. The tire correlation stuff we do with Michelin. And it’s paying dividends. I think we all spend – myself, like 60 days last year in the sim. When we can roll out on track and the car matches, we can do a lot of pre-work. And that shows at these sort of tracks.

“It’s all through the hard work. There’s so much work going on at the tech center as well. We just get to execute on a weekend like this, and get the glory on the podium. But there’s a whole army of people that make it happen too.”

Soon, Aitken and Bamber will pack their bags for the 24 Hours of Le Mans, where they’ll drive the No. 38 Cadillac Hertz Team JOTA entry alongside Sébastien Bourdais, aiming to score a first Le Mans overall win for Cadillac.

And with the momentum on their side going into this year’s edition of the Grand Prix d’Endurance, there may be another special moment yet to come for the duo that’s been leading the charge for Cadillac this year.