To say that the world has changed since the previous Porsche Formula E tech feature (#271/April 2020 issue) would be a gross understatement. Like much of the rest of the world, the FIA ABB Formula E championship hit the pause button not long after that article was published, and after canceling or suspending several races, the organizers found a way to safely restart the series in August 2020 amidst the prevailing global pandemic, supply chain issues, and an ever-changing landscape for the automakers and suppliers.
The Gen2 era of 2018-2022 proved to be an exciting and competitive series. However, despite most major automakers offering an ever-increasing amount of electrified road cars, several prominent German manufacturers pulled out of the Formula E (FE) championship after the 2021 season, including Porsche’s stablemate Audi and rival BMW. The Mercedes team also announced their imminent departure from the FE series at the end of 2021, immediately after winning both the driver’s and constructor’s championship trophies.
Porsche, Jaguar, Nissan, DS, and NIO remain as major manufacturer teams, though McLaren has since taken over Mercedes’ UK-based FE outfit, and the addition of Maserati provides another well-known name in the series. Indian conglomerate Mahindra is also fielding a Gen3 FE car, whose debut at the Goodwood Festival of Speed in late June 2022 marked the public debut of the new Gen3 platform. The remaining four teams are independent entries, most of whom rely on the major manufacturers for their powertrains.
For the upcoming 2023-2024 season, Porsche will, for the first time, provide its powertrain to a customer team (Avalanche Andretti racing, which previously used BMW power). This not only helps Porsche to amortize the costs of participating in the FE series, but it also opens the possibility of the teams sharing data in an effort to advance their mutual goals.
Porsche in Formula E
Despite the Porsche factory’s vast amount of experience in numerous disciplines of racing, the journey of the Porsche FE team has not been easy. The team languished mid-pack for much of its inaugural 2019-2020 campaign while coming to grips with the extremely narrow window in which teams can distinguish themselves in terms of energy management and race strategy.
The Porsche team was disqualified immediately following what would have been their first FE win at the 2021 “E-Prix” in Puebla, Mexico by driver Pascal Wehrlein. This resulted from the invocation of a little-known rule about the team incorrectly submitting their tire allocation to the FIA before the race start. By that point of the season, however, the team had hit its stride, and both Porsche drivers consistently scored points finishes during the second half of the season.
A snafu during the recent 2022 Marrakesh E-Prix provided an example of the challenges of running an all-electric racing car with the requisite battery safety measures. Battery temperature management is of utmost importance to ensure the safety and longevity of the battery cells, and the extremely high ambient temperatures during the Marrakesh race compound this issue.
Driver Pascal Werhrlein was severely down on power immediately following the race start, and it was discovered that the issue was a programmed re-initialization of the lithium-ion battery pack’s temperature model, which occurs any time the main power is shut off for more than 300 seconds. Wehrlein’s car had been switched off for slightly longer than the 300-second threshold, so the programmed safety algorithm limited power output while the battery temperature model re-learned.
However, the Gen2 Porsche 99X has proven to have good pace during qualifying sessions, with driver Andre Lotterer being the only driver in the series to make it to all the final elimination rounds of each qualifying session of the Season 8/2021-2022 campaign. For the 2023-2024 season, Lotterer will move over to the customer Avalanche Andretti team, with 2019-2020 FE champion Felix De Costa taking his place in the factory Porsche factory car.
The Gen3 Car
The “Gen3” FE car will have its race debut in January 2023 for Season 9 of the series. As with the previous FE race cars, the Gen3 platform is mostly a spec car with a carbon fiber monocoque chassis supplied by Spark Racing Technologies. Whereas the Gen2 formula allowed the teams to develop their own rear suspension setup (excluding uprights), the Gen3 rules dictate the specific suspension configuration and geometry (standardized dampers will be provided by Sachs). The bodywork design is also fixed. In the meantime, the only aspect of the car that can be modified by individual teams is the electric powertrain, which includes the motors, transmission, and the power electronics.
Porsche had only just begun testing its new Gen3 car at press time, once at its own Weissach test track and once at the Calafat Circuit near Tarragona, Spain. Therefore, the team is mum about the specifics of its powertrain, but the next-gen 99X racing car will share most of its features with its rival cars. The Gen3 Formula E car expands on the FE series objective to promote a more sustainable form of racing by not only providing a lighter and more efficient racing car, but also increasing the rate of recyclability of the car’s components, all while improving the overall performance of the cars.
One of the most noticeable aspects of the Gen3 car is its “fighter jet” looks, which are partially driven by aesthetics, but also provide a meaningful amount of downforce while remaining aerodynamically efficient. Another prominent change is a return to a true open-wheel configuration, partly due to the propensity of wheel-to-wheel contact in the FE series resulting in many shards of carbon fiber from the Gen1 and Gen2 wheel covers littering the track; this is at odds with the “sustainability” aspect promoted by the series.
To this end, the bodywork of the Gen3 cars will be composed of recycled carbon fiber, much of which will be gleaned from the outgoing Gen2 cars. While recycled carbon fiber does not have quite the strength-to-weight ratio of virgin carbon fiber, its formation is not nearly as energy-intensive as the weaving and formation of new material.
The Gen3 car is smaller in every dimension than the first two FE chassis, with the most notable change being a 129.5 mm (5.1 in.) shorter wheelbase, which will improve agility and handling in the narrow street circuits on which all FE races are held.
A main feature of the Gen FE platform is more energy throughput in both the propulsive and regenerative realms: the rear axle motor output is increased from 220 kW (335 hp) to 350 kW (470 hp). There is an additional powertrain for the front axle, though it will initially only be used for regenerative braking purposes and will not provide propulsive force. The 250 kW of regenerative capacity of the front motor unit augments that of the rear powertrain for a combined capacity of 600 kW, which more than doubles that of the Gen2 car. The minimum efficiency of the electric powertrain is a claimed 95 percent (compared to less than 40 percent for a combustion engine), though the teams will likely eke out even more efficiency during the Gen3 era.
The massive increase in energy recovery allows for a smaller and lighter battery back (which is again supplied by Williams Advanced Engineering). Overall, the Gen3 car is 60 kg (132 lbs) lighter than its predecessor at 840 kg (1,848 lb), including driver weight. Another reason for the reduced mass is a lack of hydraulic rear brakes; all the rear braking torque of the Gen3 car will be provided by the rear motor unit. The tight, street circuit-only format of FE is conducive to recuperating electrical energy during braking by reversing the current flow within the motor(s) during deceleration and braking, which is also a feature of road-going hybrid and electric vehicles. However, the regenerative braking of FE cars is very aggressive; the Gen2 powertrain harvested about 25 percent of its energy via regenerative braking, while the Gen3 setup increases this figure to more than 40 percent.
Many FE teams have already struggled to maintain optimal brake balance and feel during both the Gen1 and Gen2 eras, so the additional challenge of manipulating the software to smoothly blend the split between hydraulic and regenerative braking, in terms of performance and consistent pedal feel for the driver, is likely to be at the forefront of the Gen3 car setup. The FIA release statement about the Gen3 car highlights the importance of software in the series: “While aerodynamic development programs have been central to driving incremental improvement in motorsport for decades, the launch of the Gen3 propels software engineering forwards as a new battleground for motorsport innovation and competition. Performance upgrades to the Gen3 will be delivered as software updates directly to the advanced operating system built into the car.”
All Gen3 FE cars will be shod with a Hankook spec tire, replacing the previous Michelin version. As before, there is only a single all-weather tread compound and configuration, which reduces the overall carbon footprint of the series; however, the Hankook tire is expected to be closer to a racing tire than its predecessor. The FIA also touts the new tire’s composition of 26 percent of its materials coming from recycled sources, and these tires will be extensively recycled after they are used.
The lighter, nimbler Gen3 car is projected by its designers to be about two to four seconds quicker per lap on the average FE street circuit than its predecessor, which will provide more excitement for drivers and spectators alike. The calculated top speed of 200 mph is also impressive, though this velocity is unlikely to be approached on any of the street circuits on the FE calendar.
The final sporting regulations for the 2023-2024 season are yet to be fully defined at press time, but the return of pit stops is expected; instead of changing cars as in the Gen1 era (2013-2018), rapid charging of the batteries will be deployed. While this format has not been finalized at the time of writing, the proposed 600 kW charging rate is double that of the Porsche Taycan road car. The rapid charging system is currently being evaluated by the teams, and the great hope is this technology can be applied to future road-going electric vehicles and the requisite charging stations.
To cap operating costs, the FIA has, from the inception of the FE series, limited the amount of data the teams can monitor via onboard telemetry. Besides the cost of the hardware, the paucity of sensors obviates the need for teams of highly-paid engineers to pore over the data as in series like Formula One. There are explicit bans on sensors for aerodynamic pressure sensors and wheel speed sensors—the latter ban is to preclude the implementation of traction control systems as installed in any road car, which is illegal in Formula E.
Nonetheless, rumors have abounded about teams implementing traction control systems in an effort to control the considerable amount of wheelspin possible with the torquey electric powertrains as the cars scrabble for traction out of tight turns. One such story is that some teams were using high-speed cameras to monitor markings on the inboard sidewalls of the tires, which could be used to calculate wheel speed.
Another controversial sensor in the FE world is the driveshaft torque sensor. There are several different types—some measure surface strain of the driveshaft, and others can detect the deflection of the driveshaft material caused by the applied torque. Many FE teams have used these torque sensors for non-racing development work, but the FIA is expected to mandate their installation so the regulators can monitor for illegal traction control systems.
The FIA-mandated torque sensor will be a more advanced type that can monitor changes of the intensity of the magnetic field surrounding a pre-magnetized section of the driveshaft; these MagCanica-made sensors are already used by Formula One teams. Any sudden deviation from the usual deflection of the driveshaft that might be caused by an illegal software algorithm artificially limiting the motor’s torque output could be considered an infraction of the rules. This will likely prove difficult for the race stewards to police, but it will add an interesting wrinkle to the series.
Formula E technical manager Alessandra Ciliberti has already hinted at the possibility of upgrading the front powertrain to provide tractive force and true all-wheel drive for the second phase of the Gen3 car; however, this will likely only be available during race starts/launches and “attack mode” phases rather than a full-time feature. Another expected change for future seasons is the ability for teams to customize the bodywork in future seasons, though this appears to fly in the face of stricter financial regulations coming into effect in October 2022.
Despite the pullback from some other major manufacturers, Porsche appears to be committed to success in Formula E, at least for the near term. The ever-persistent rumors of Porsche entering the fray of Formula One were confirmed recently by Volkswagen Group CEO Herbert Diess, with both Porsche and sister company Audi fielding a team for the 2026 season (which is when the next major change of F1 technical regulations will take place).
Porsche’s major investment in synthetic fuels will likely pay dividends, as the 2026 F1 regulations are expected to mandate the use of such fuel. The question remains whether the team from Weissach will be able to field both an F1 and an FE campaign in addition to its usual sports car activities. In any case, Porsche racing fans will have a lot to look forward to during the next few years!