Gen 3 Formula-E takes shape
Porsche is among the first teams to take the wraps off the Gen 3 racer. 99X gets new 469bhp powertrain, less weight, more efficiency and even quick charging
THE MOTOR IS NOW NOT A SPECPART BUT DEVELOPED IN-HOUSE
PERHAPS THE BIGGEST CHALLENGE, and the main area of research in e-mobility, is the quest for efficiency and that has been the primary focus area with the third-generation of the Formula E single-seater electric racing series. Porsche were among the first of the teams to reveal its Formula E car, the 99X making its debut in Italy, and we got an opportunity to get an insight into the technical development of the season 3 cars ― one that hasn’t been without its challenges.
This being a race car the headline figure is of course the jump in power from 335bhp to 469bhp in qualifying mode and the motor is now not a spec-part but developed in-house by Porsche Motorsport. “The car is all about efficiency,” says Martin Füchtner, technical project leader of the Formula E project. “We have more recuperation so less power is needed.” Key to this is the newly added front motor that is used for recuperation and can add up to 250kW of (recuperated) energy to the 350kW (from the battery) on the rear axle. The resulting energy recovery with an output of up to 600kW (805bhp) is more than double the regenerative capability of the Gen2 vehicles. In fact recuperated energy accounts for more than 40 per cent of the power deployed during a race says Porsche. The recuperation is so strong that hydraulic brakes are no longer needed on the rear axle while the friction brakes are controlled by a brake-by-wire unit and balancing the two particularly ensuring consistency for the driver is a big challenge says Martin. “AWD recuperation is a key element but drivers need to have maximum trust in the brakes.”
The batteries are also new, advances in cell technology making it smaller but allowing it to hold more capacity. The direct consequence is reduced overall weight of more than 50 kilos from the previous 903kg to under 850kg. There has also been a reduction in wheelbase (129.5mm), length (183.8mm) and width (100mm) making for a more agile car and better suited for wheel-to-wheel action on narrow street circuits. Porsche claims the increased outputs also lead to significantly greater acceleration and top speed, aided by the aerodynamics and new design of the Gen 3 racers, the most striking feature of which is the angular design and omission of the wheel covers ― an overall theme now appealing more to the Playstation generation.
The chassis, batteries and aerodynamics are standard across Formula E with manufacturers and teams focusing their energies on the powertrain and cooling. Sustainability is a key talking point with the Williams Advanced Engineering batteries recycled or reused at the end of each season while the carbonfibre used in the chassis will be recycled from retired Gen-2 cars reducing the carbon footprint of production by more than ten per cent.
One facet of the Gen 3 cars that will not be seen at the start of the season is the ultra-high-speed charging that should add around 600kW of energy during the race ― this is like the refuelling pitstops in Formula 1. This charging rate is almost twice as powerful as the world’s most advanced commercial chargers and is one of the technologies that aims to be developed on the track for future use in road cars. But Martin says the key knowhow that will transfer to Porsche’s next generation of electric road cars, and a key performance factor for the 99X, is software engineering ― managing all-wheel-drive recuperation with the brake-by-wire friction brakes, handling all the reams of data real-time during the race weekend, policing power and torque deployment through the race, and mastering the control algorithms to race a more energy efficient race car. Efficiency, after all, is the key and with Gen 3 efficiency of the drivetrain goes up to 95 per cent and beyond compared to around 40 per cent for the best combustion engines. ⌧