There are many aspects of the Endurance World Championship that often go unnoticed, and one of the most critical is software management, which plays a key role in controlling power delivery. Experts frequently emphasize how important it is to fully understand how to manage the software. Cyril Abiteboul, interviewed by DailySportscar, also highlighted this aspect.
Several manufacturers have acted on this aspect using specific “Jokers.” Cadillac undertook a similar approach, emphasizing the importance of such a hidden component. Thanks to software, significant differences can be observed between manufacturers. Let’s take a closer look at how it can make a difference.
WEC – Software management: why and how it can make a difference
Analyzing the LMH and LMDh regulations in WEC and IMSA reveals notable differences. Globally, LMDh cars have many standard elements that cannot be modified in-house. As a result, discrepancies often come from software, which can make a huge difference in power management. It’s not just about how much speed you have but how you manage it.
When hardware components cannot be modified, except through Joker interventions, software becomes the primary tool for optimization. First, however, the layout of the components within the prototypes must be analyzed to obtain a clearer overall picture.
Once the input is given, power is managed by the control units: the ECU (Engine Control Unit) handles the internal combustion engine, while the HCU (Hybrid Control Unit) manages the electric components. As expected, the ECU controls factors such as throttle opening, fuel injection, and available torque, while the HCU manages elements like the MGU, inverters, and energy recovery.
It is clear that software plays an essential role: it manages the output power from both the internal combustion engine and the electric motor, including all regeneration, while remaining within the limits set by the regulations. Electric power, before reaching the MGU, passes through the inverter, which converts the battery’s power to ensure the electric motor and battery work in harmony.
Without the inverter, the battery could not deliver energy, nor could the MGU recharge it during lift phases. The conversion from direct current (battery) to alternating current (MGU) is essential for generating speed and torque. Software acts directly on the inverter, which in turn affects the motor.
Thus, software is effectively the architect of the entire power delivery phase from the power units, all while complying with technical regulations. Once it receives input from the driver, the software also acts according to BoP limits, taking into account factors such as track conditions, available energy, and race strategy.
WEC – Software management: Ferrari’s advantage
Through torque shaping, software manages and modulates the torque from both the internal combustion engine and the MGU, avoiding wheelspin or excessive energy consumption. On the electric side, this illustrates the complexity of gaining an advantage under LMDh regulations.
Inverters, HCU, MGU, wiring, and sensors are all standard Bosch components, along with rear-wheel drive. Therefore, advantages are almost entirely in software management. ECU and ICE, on the other hand, are free components, designed by manufacturers.
Ferrari has an advantage in how it manages space and power on the 499P. Unlike other cars with more common solutions, the 499P features a six-phase electric motor control. The inverter has six separately controlled wires instead of the usual three, enabling more precise control of electric power, reducing mechanical vibrations, and improving efficiency. According to Racecar Engineering, the 499P inverter is integrated into the battery, optimizing space and weight—a key advantage of adhering to LMH regulations, which allow greater design freedom and attention to detail.
Efficiency means maximizing available power while minimizing wasted energy. An efficient inverter also improves temperature management, extending the life of components and the cooling system.
Ferdinando Cannizzo commented on Ferrari’s solution: “There has been significant research into the materials of the electric motor, the electronic power of the inverter, and the way to associate it with the MGU as efficiently as possible,” stated the Head of Endurance Cars. “The more efficient the control, the better for the inverter’s life, since less heat is generated for the same power, resulting in lower electronic component temperatures and less demand on the cooling system,” he added.
All of this is combined with the complexity of the electric system, featuring around 300 sensors on the 499P, managed by control units mainly located in the cockpit area. The first ECU software for the car was released in May 2021. Recovery systems have also been developed to handle electronic failures, as seen at Le Mans 2023 during the last pit stops.
WEC – Software management: is front-wheel drive really an advantage for LMH?
LMH regulations require a front-mounted MGU-K, which delivers power to the front wheels above 190 km/h. This provides an advantage at high speed but introduces complications. Drivers have reported that front-wheel boost at high speeds, such as in the final Porsche curves at Le Mans, generates understeer. Antonio Giovinazzi noted that the front ‘push’ can be felt at high-speed corners.
Cannizzo explained the pros and cons: “When you have a front motor, you need to match its speed to the wheels. At maximum speed, the wheels rotate around 3000 rpm, while a rear electric motor rotates at engine speed, which is three times faster.”
“In our case, we must drop from 25,000 rpm to 3,000 rpm: that’s a huge reduction. The rear electric motor is more complex to manage, as it must follow the engine rather than the wheels. There are different challenges,” Cannizzo added. “But they can apply torque via the ERS system and combine it with the engine during acceleration and braking.”
Having the MGU at the rear focuses attention only on the rear axle. “They have no limits in applying ERS power, which reduces lag at low speeds. There’s a clear difference between LMH and LMDh: LMH with larger engines have advantages but also some drawbacks compared to LMDh. The Valkyrie’s motor represents a good compromise.”
This year will see many changes in WEC and IMSA. Several teams will introduce Jokers; Genesis will enter with a new car, and Abiteboul emphasized the importance of investing in this direction. Toyota will arrive in Qatar with the new TR010 Hybrid, related to the older GR010 Hybrid. This will mark a period of understanding new packages, combined with new Michelin tires.
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