The regulations for the top class at Le Mans have been finalised as the ACO, FIA and IMSA published the LMDh rule set at the end of March. These regulations, based on IMSA’s philosophy of low-cost Prototype racing, sit alongside the LMH rules that were designed by the FIA and ACO, and together they form the top class, named Hypercar, in the World Endurance Championship, and GTP in IMSA.
While the LMH regulations have been public for a long time, allowing Toyota and Glickenhaus to race in the WEC in 2021, the LMDh regulations have taken a little longer to finalise. The teams and manufacturers have had a version of them since September 2020, but the process of bringing the two rule sets together has been complicated.
The highlights of the LMDh regulations have been known for some time. They are essentially a chassis from one of four constructors – Dallara, Multimatic, Ligier and ORECA. They build the ‘spine’ of the car, including the monocoque, suspension, and brakes. This spine will be used to form the LMP2 cars of the future.
British companies Xtrac and Williams Advanced Engineering provide the gearbox and battery elements of the hybrid system respectively, while Bosch provides the MGUs for the cars.Each LMDh car will carry the same specification gearbox and hybrid system.
Manufacturers take the homologated chassis from their chosen constructor, and introduce their own engine, cooling packages and bodywork. The
