LMH Prototypes Set To Compete In IMSA In 2023

ACO, FIA, And IMSA logos. LMH Prototypes Set To Compete In IMSA In 2023

In early 2020, the Automobile Club de l’Ouest (ACO), the Fédération Internationale de l’Automobile (FIA), and the International Motor Sports Association (IMSA) had announced their intention to create a joint top class for endurance racing. The three parties, along with the help of manufacturers, have announced an agreement on the technical specifications for the new category, which means LMH prototypes will be able to compete in the IMSA WeatherTech SportsCar Championship beginning in 2023.

The specifications aim to allow cars with different technical definitions to compete alongside one another in the FIA World Endurance Championship and the WeatherTech Championship. These cars are the LMH (Le Mans Hypercar), officially introduced in 2021, and the LMDh (Le Mans Daytona h), officially introduced in 2023.

“What we achieved as a group... has the potential to revolutionize prototype sports car racing all over the world. The stage is set for a highly competitive top category that will include many of the world’s greatest automotive manufacturers, showcasing relevant technology in the world’s most prestigious endurance races,” IMSA President John Doonan said. “Collectively, we have an opportunity to engage with the next generation of endurance sports car racing fans and elevate our sport to the highest levels.” 

All specifications for tire fitment, acceleration profile, braking capability, and aerodynamics were approved by the World Motor Sport Council (WMSC). To view the key technical elements, visit here

Tires (Front/Rear Width in cm):

  • AWD: 31/31
  • RWD: 29/34

Acceleration Profile:

  • AWD: Activation speed deployment will be BOP tool (removed from TR) and it will be monitored with PDST (from Speed 1 to Speed 2)
  • AWD: Due to the track variations in global competition, there will be two BOP activation speeds (dry/wet linked to tire fitted to the car). With our current knowledge, a 120-160 kph range would be implemented
  • LMDh: Control software to limit the contribution of eMotor to traction control capability

Braking Capability:

  • AWD & RWD: Total differential potential on coast identical on all cars (AWD = Fr + Rr, RWD = Rr)
  • delta torque front axle + delta torque rear axle
  • Limit overall delta torque = function (virtual engine drag power, virtual locking ratio)
  • AWD: Front differential with a zero-lock mechanism on coast (twin or single eMotor)
  • delta torque front axle


  • LMH
  • Homologation = Sauber
  • Taking part in IMSA = wind tunnel characterization in WindShear
  • LMDh
  • Homologation = WindShear
  • Taking part in FIA WEC = wind tunnel characterization in Sauber

For more information, visit imsa.com.

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