LMDh to replace DPi in new IMSA ACO convergence

Image by Rainier Ehrhardt/LAT

LMDh to replace DPi in new IMSA ACO convergence


LMDh to replace DPi in new IMSA ACO convergence


IMSA’s defining Daytona Prototype internationals will be replaced by a new formula named LMDh. LMDh is what has been referred to as DPi 2.0.

The acronym LMDh, which was not defined by the ACO or IMSA in Friday’s announcement at Daytona International Speedway, could come to stand for ‘Le Mans Daytona hybrid’ once both parties agree on the final moniker.

Under the terms outlined in the new convergence agreement between IMSA, and the French organization that runs the 24 Hours of Le Mans and creates the technical regulations for numerous endurance racing classes, LMDh will be eligible to compete in Europe starting in September of 2021.

The ACO’s new Hypercar class, which debuts in September of 2020 when the 2020-2021 FIA World Endurance Championship season begins, will serve as the WEC’s top prototype class for one year before LMDh is introduced as an alternate style of prototype for manufacturers to build and use as desired.

In North America, LMDh is scheduled to supersede DPi at IMSA’s season-opening Rolex 24 At Daytona race in January of 2022.

No mention of grandfathering the first-generation DPis into the blended LMDh/Hypercar class was mentioned in the convergence press release, which suggests that once the current DPi cars complete the 2021 WeatherTech SportsCar Championship season, new prototypes built to the LMDh rules will take their place.

The formation and execution of LMDh will follow practices that have worked well in DPi since its 2017 launch. Like the existing LMP2-based DPi regulations, where four approved chassis constructors — Canada’s Multimatic, France’s Ligier and ORECA, and Italy’s Dallara — supply auto manufacturers with customized cars using stylized bodywork to carry their preferred choice of engines, the ACO and IMSA have signed contracts with the same four companies to produce LMDhs.

In another carryover of current practices, the new, base LMP2s (pictured above at Le Mans last June) produced by the four constructors in 2021 will remain as the only options for LMP2 entrants to purchase and race.

Ongoing efforts by IMSA to identify a spec kinetic energy recovery system (KERS) will be completed and made mandatory for every LMDh model. The hybrid internal combustion engine (ICE) and KERS package will drive the rear wheels, where energy harvesting will take place under braking and be fed back to the rear tires to boost acceleration. An electronic horsepower target in the 40-50hp range remains.

No target power figures for the ICE side of the propulsion system was mentioned, but that increased number — along with the full scope of LMDh’s technical regulations — is expected to be revealed at the combined IMSA and FIA WEC event in March at Sebring.

Manufacturers will be asked to incorporate more readily identifiable styling cues with their LMDh models. Where the first-gen DPis have taken moderate steps to bring road car design elements into their bodywork, some look very similar to the stock LMP2s they’re built upon, which should be rectified with LMDh.

Manufacturers’ road car lineage figures to be more visible in LMDh. Image by Alexander Trienitz/LAT

With manufacturers having called for prototype convergence, the ACO and IMSA rule makers would be expected to embrace some degree of flexibility in the construction parameters for LMDh. As new technological advancements emerge during the LMDh era, designing open spaces into the chassis, engine bay, and sidepods to outfit cars with new and emerging technologies during LMDh’s lifespan would fit the manufacturer-driven spirit of the formula.

Although no formal commitments to LMDh are expected in the immediate wake of the announcement, it’s believed the cost-effective prototype concept will be met with significant interest.

Of the rumored new manufacturers on the LMDh horizon, Ford, Lexus, McLaren, and Porsche are among the major brands that could join Acura, Cadillac, and Mazda at Daytona, Le Mans and other famous endurance events in the next two years.

Peugeot, which announced a Hypercar program for 2022, is expected to shift its plans to LMDh, giving the new formula another famous manufacturer to bolster its ranks.


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