BMW confirmation adds to growing momentum behind LMDh

IMSA’s next-generation prototype class continues to go from strength to strength with the confirmation of a new LMDh program from BMW in 2023.

The German auto manufacturer will line up alongside rivals from Acura, Audi, and Porsche among those who’ve announced plans to take part in the class that will replace DPi. Cadillac is expected to become the fifth brand to endorse LMDh with a new factory program, and Lamborghini – sister brand to Audi and Porsche – is tipped to become the sixth.

Across the pond, the WeatherTech SportsCar Championship’s partners at the ACO and FIA WEC have already opened its new era with the LMH formula, its replacement for LMP1. While there are few takers to start, Toyota have been joined by Scuderia Cameron Glickenhaus and, in 2022, Peugeot is coming; Ferrari is due in 2023.

Together, IMSA’s LMP2-based LMDh category and the wide-ranging options afforded by the WEC’s LMH regulations have given rise to strong involvement from major and boutique manufacturers. Speaking ahead of IMSA’s Chevrolet Sports Car Classic race on Saturday at Detroit’s Belle Isle, series president John Doonan said the momentum continues to build as LMDh takes shape.

“We’d like to welcome BMW back to the top category,” Doonan told RACER. “They’ve clearly had great success in the GT ranks for decades, so to have BMW returning to prototype racing in IMSA with LMDh is a wonderful development. And overall, the interest in LMDh continues to be strong; based on feedback from other auto manufacturer partners that have been at the table, there’s more public announcements to come.”

A renewed vigor to find ways that would allow LMDh and LMH models to compete in the same WeatherTech Championship class is also part of ongoing discussions between IMSA, the ACO, and the WEC.

“We’re encouraged by the technical discussions that continue to be lively,”Doonan said. “And I’d like to reinforce another element of this, which is a big question on people’s minds around convergence of LMH and LMDh. When it comes to balancing the two categories, IMSA remains open to the idea of convergence, meaning LMH and LMDh cars competing on the same tracks, at the same time, in a single top category. But we also want to reinforce that it’s got to be done in a proper process to make sure that we all feel comfortable with the ultimate technical solutions.”

With the LMDh cars welcome to compete in the WEC and at Le Mans from the outset in 2023, IMSA has been more cautious in granting permission for the LMH cars – with two years of racing and development in hand – the same immediate green light to race in IMSA while the new LMDh cars are at the beginning of the developmental process.

In IMSA, all LMDhs will make use of a spec 40hp KERS unit powering the rear wheels; in LMH, purebred cars, road-based cars, custom KERS units, front-wheel-drive KERS deployment, and equal tire widths on all four corners are allowed. From a conceptual standpoint, LMDh is tightly controlled while LMH offers exceptional freedom, which will make aligning the formulas and achieving performance parity a monumental task to achieve.

But where the door once appeared to be shut on LMH in IMSA in 2023, Doonan suggests it’s no longer an impossibility if the right technical tone can be found.

“It’s incumbent upon us to show the different automakers investing in LMDh and LMH that we’ve done our due diligence,” he said. “It’s working with how the hybrid systems deploy in the two different categories, how the aero specifications of the different formulas align, how the hybrid systems deploy, how two-wheel-drive and four-wheel-drive cars compete on a balanced platform with one another. And ultimately, how does the BOP work?

“And while it’s an extremely complicated set of topics, the simpler that we can identify the ways to race together and tell the story, the better off we are. So lots of positive momentum, a lot of interest from manufacturers, and an ongoing discussion about the ability for the two platforms to coexist.”

As the LMH cars continue to race and improve, Doonan expect to see the first LMDh models begin track testing in the next 10-12 months once the initial batch of KERS units are completed and distributed to the manufacturers and their chassis partners.

“Among the LMDh manufacturers in terms of launch timing, I think there’s going to be rollouts and unveilings towards the end of the year and in January at Daytona,” he said. “And the efforts by Bosch, Williams and Xtrac to provide and produce the hybrid powertrain system, which has been making great progress, will probably have track testing happening in the first quarter of next year, maybe the second quarter. We know the OEMs can’t wait to get going to prepare themselves for what’s coming to race in IMSA in 2023.”