ABT Schaeffler FE02: Efficiency in focus

Formula E is the first clean electric racing series in the world. But for Audi, it is not only the powertrain concept that is uncharted territory. For the first time ever, the brand with the four rings is committing to a single seater category.

Rally, Trans-AM, IMSA-GTO, DTM, Supertouring cars, Le Mans prototypes, GT3, TT Cup, TCR – the rally and circuit race cars from Audi Sport have until now all had one thing in common: closed wheels. With Formula E, Audi is now expanding its motorsport program by single seater race cars featuring exposed wheels, as known by fans of Formula 1 and IndyCars in America.

For the first Formula E season in 2014/2015, completely identical electric race cars were used, but for the 2015/2016 season, teams themselves were allowed to develop specific assemblies for the first time. Examples included proprietary powertrains as well as modifications to the chassis. This principle has been kept for the 2016/2017 season.

The ABT Schaeffler FE02 is therefore an evolution of the successful previous model with which Daniel Abt and Lucas di Grassi achieved ten podium positions last season -- three being victories. The engineers mainly focused on making the combination of the electric motor and the transmission even more efficient. This included lower weight and an optimized center of gravity, faster shift times and higher torque.

Similar to the DTM, technical changes after the homologation of the race car, which takes place once a year, are no longer allowed. During the season, the engineers and drivers are primarily concerned with making the most of the existing package and perfectly adapting the car to the respective street circuits. The software, which plays a crucial role in Formula E especially in terms of energy management, offers the greatest latitude for modification.

The heart of the race car is an approximately 200-kilogram energy accumulator (Rechargeable Energy Storage System, RESS) that was developed by Williams Advanced Engineering and is identical in all of the cars. The lithium-powered battery has a capacity of 34 kWh, of which 28 kWh is allowed to be used.

The Motor Generator Unit (MGU) is controlled using a single controller from McLaren Electronics. The MGU itself is a development of Schaeffler. In qualifying, its output is limited to 200 kW (270 hp) and in the race to 170 kW (231 hp). Three drivers each receive extra power of up to 200 kW (270 hp) by fans voting in the so called “FanBoost.”

For power transmission, ABT Schaeffler Audi Sport continues to use a three-speed unit which in the last season proved to be a good compromise. The driver can shift the three gears, like in the Audi R18 or the Audi RS 5 DTM, using paddle shifters in the steering wheel. The clutch, which is only used at the start and at the pit stop, is also operated on the steering wheel. A central display provides all the important information about the condition of the MGU, especially the system temperatures which are particularly important in an electrically powered race car.

A special feature of Formula E is the profiled all-weather tires, which are supplied by longtime Audi partner Michelin and have close relevance to the series. The cars themselves resemble Formula 1 race cars. For better distinction they have been given a striking double front wing for the 2016/2017 season, which differs considerably from the front wings of other single seater series.

Like in Formula 1, the drivers sit in a carbon fiber monocoque conforming to the latest FIA safety standards. Two roll bars and CFRP crash structures at the front, the rear and the sides ensure maximum safety. The minimum weight of a Formula E car is 880 kilograms (with driver). The electric car accelerates from 0 to 100 km/h in 3.5 seconds. The top speed is 225 km/h.