Unveiling the Porsche 963 Hypercar’s Advanced Braking System

Porsche’s 963 hypercar brings a new level of complexity to endurance racing, especially when it comes to stopping the car. The team at Porsche Penske Motorsport had to adapt to fresh regulations in the World Endurance Championship (WEC) and IMSA by building a new car for the LMDh class.

The 963 is powered by a hybrid system combined with a 918-inspired V6 engine. This has required Porsche to modify and rewrite software to manage the car’s advanced braking system, which is far from ordinary in its field.

While the braking system in the LMDh machine resembles Formula 1, distinct regulations add layers of difficulty. The car uses hydraulic brakes at the front, but a brake-by-wire system is used at the rear due to the hybrid setup.

Bosch supplies the Electronic Braking System (EBS) that manages how force is distributed among hydraulic brakes, regenerative braking, and engine braking. The Motor-Generator Unit (MGU), inverter, and control software are also Bosch developments.

The LMDh format allows teams to shape their braking strategies by changing how the pressure is delivered to the brakes, giving flexibility on race day. Brake bias is another fine-tuning tool for drivers.

This setting changes how much braking force goes to the front versus the rear. As the car slows, weight shifts forward and adjustments here can affect how steady or loose the car feels, especially when entering corners.

More front bias can produce a looser, more agile car, while more rear bias brings extra stability and greater understeer. The system also allows for brake migration, using electronics to shift bias throughout a corner.

This is adjusted by drivers in real time, sometimes changing from one corner to the next to match grip and evolving race conditions. The EBS constantly manages a blend of friction braking, electricity generation by the MGU, and the internal-combustion engine.

There are no hard limits on regeneration, except for the battery’s state of charge or the MGU’s limit of about 180 kilowatts, which translates to 241 horsepower. During heavy braking at places like Indianapolis corner, as much as 40 percent of all rear braking can come from the hybrid system.

The battery’s state changes lap by lap, so the ratio of mechanical to regenerative braking is never static. Teams are always working to find the best possible energy management, balancing battery charge, brake temperatures, and wear in real time.

Drivers like Felipe Nasr make dozens of adjustments each lap to tune brake bias and migration values. Their goal is to maintain control and feel, since hybrid and brake-by-wire systems can sometimes lead to odd pedal responses.

Bosch helps with a pedal-feel emulator, but how the pedal feels is a decision made between the automaker and engineers. Drivers need instant and predictable braking from 200 mph to beat rivals into corners without confusion or electronic mistakes.

Even with Porsche’s past experience using blended braking in the older 919 LMP1, the challenges of the 963’s new hybrid layout meant code and systems had to be redeveloped. Technical director Stefan Moser confirmed that putting the MGU on the rear axle involved far more work than expected.

Each team can develop its own approach, even though the hardware is mostly the same across the LMDh class. Years of progress have made the Porsche 963 easier to drive since its debut in 2023, but heavy braking zones still test both drivers and engineers.

Teams joining LMDh in the future will face the same steep learning curve as Porsche did, building their own software and strategies for the intricate systems that now define top-level sports car racing.

Daniel Miller

Daniel Miller reports on Formula 1 Grand Prix weekends with race-day analysis, team-radio highlights, and point-standings updates. He explains power-unit upgrades, aerodynamic developments, and driver rivalries in straightforward, SEO-friendly language for a global F1 audience.