This week sees the finale of the 2020 IMSA Sportscar Championship get underway with the 12 Hours of Sebring. It also sees the beginning of the end of the DPi cars, the current top class in IMSA competition.
Changes for 2022
Both Mazda and Cadillac are scaling down their factory-backed entries, whilst Acura will be withdrawing altogether, allowing its pair of ARX-05s to be campaigned in private hands.
We’re going to be rounding everything we know of their, now finalised, replacement for 2022: the Le Mans Daytona hybrids, or LMDh.
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As the name suggests, there have been 2 key areas on change within the regulations. A hybrid aspect has been introduced to reinforce relevance to current road car technology.
Also, the ruleset has been developed in tandem with the ACO, leading to the long awaited convergence of top-flight prototypes between the American IMSA and global WEC series.
As with the outgoing regulations, the existing chassis theory will be maintained for LMDh. All cars in the class will be based on a new generation 2023 spec LMP2 “spine”; this being the complete car, minus any of the powertrain or bodywork components.
These will be constructed by the one of the 4 mandated manufacturers set by the FIA (Multimatic, Oreca, Dallara and Ligier). All will share common dimensions of 5.1m length by 2m width with a wheelbase of 3.15m.
Minimum vehicle weight is set at 1030kg, while a downforce to drag ratio of 4:1 has been specified. This simply means that for every 4 kilos of downforce being produced by the aerodynamics, they must produce 1 kilo of drag as a result.
This will prevent huge budgets being poured into aero development, keeping costs down and racing close. Further to this, all cars will also share a control floor design.
One key draw of the DPi class was the ability for surface bodywork to be changed in order to better reflect a manufacturer’s design language. This will continue with the new class, theoretically allowing teams to fully differentiate themselves from each other even if using the same base chassis.
The total maximum power output of the cars is capped at 500kW (670bhp), a portion of which is provided via a hybrid system.
In a further measure to prevent cost spiralling out of control, as is often still too easy with this technology, the entire hybrid portion of the powertrain is standardised across all entries.
Bosch supply a 50kW motor, and its associated controller, that is integrated directly into an XTrac gearbox, meaning that these cars will exclusively be rear wheel drive.
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Meanwhile, Williams Advanced Engineering provide the battery and power electronics.
As for the engine itself, the format is expected to remain similar to what we see already with the DPi cars. Manufacturers will provide their own branded engine, limited to a maximum output of 630bhp.
Costs and Interest
While the total cost of a complete rolling car, minus it’s engine, is still estimated at €1,000,000 there are some fixed costs that interested parties in the series are able to consider.
The “spine” of the vehicle, as provided by the chassis constructors, is cost-capped at €345,000 while the entire hybrid system is expected to cost a maximum of €300,000.
Although there are no confirmed entries in the class so far, IMSA is quoted as being in contact with “over a dozen” manufacturers interested in the class since convergence was announced in January, with many already working directly with one of the chassis constructors.
Included in that dozen are Cadillac, Mazda, Acura and Nissan, who would be returning from the current regulations. Meanwhile, BMW, Ferrari, Lexus and more have also been mooted, many of whom already have a strong presence in the IMSA championship via its GT classes.