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The secret of Formulec
Take a look under the skin of the innovative, all-electric Formulec single-seater
by Adam Gavine
While Formula 1 technology has undoubtedly benefited the automotive world, the stratospheric costs involved mean it takes many years to reach beyond hypercars and into the volume market. The Formulec world series, however, has been designed from the outset to benefit research into electric drivetrains.
The car you see here is the EF01, the first car developed for the series. This single-seater car is the result of a 30-month project by Segula Matra Technologies, with input from the Mercedes GP Petronas Formula 1 team. The project began with a 40% scale model, developed using the F1 team’s aerodynamic and thermal development tools, as well as its wind tunnel in Brackley, UK.
The F3-style rolling chassis is based on an existing design, and while the suspension remains standard, Segula carried out extensive work at the rear in order to accommodate the drivetrain and its cooling requirements, as well as redeveloping the floorpan. A large diffuser is also added to provide more downforce without adding drag.
With 250kW available, 0-100km/h in three seconds and a top speed of over 250km/h, the EF01 is designed to equal the performance of Formula 3 cars. Power comes from two 125kW Siemens electric motors with a power density of 2.4kW/kg, coupled to a Saft 35kWh Li-ion battery, which holds enough charge for 20-25 minutes of racing.
While these partners could supply the drivetrain technology, Segula’s F1 partner was essential for its application into EF01. Alexandre Filloux, electric formula project manager at Segula explains, “We needed technical partners, and our first was the F1 team. They helped us with the internal aerodynamics of the battery system. The fluid systems and battery systems are air-cooled, which is very complex, so we needed simulation and wind tunnel work, and Mercedes GP Petronas helped us do that.
“We worked hard on the architecture in order to integrate the battery. It is very complicated to integrate this powertain into a single-seater design. Our first idea was to do a car like a Le Mans LMP1, which is easier to integrate. But the challenge to integrate it into a single seater was very interesting. The main target was to take a leadership position – motorsport takes the lead in the auto industry. If you look at F1’s KERS, that leads [the way in] hybrid technology, and we wanted to challenge that.
“There is no specific development for the battery chemicals, etc – it is a completely standard battery, but used differently than in normal cars. All battery work was done by Saft, and is interesting as it helps them develop their products. We worked very closely with Saft to reach performance and lifetime targets.”
Another key component for the project is the two-speed clutchless gearbox, developed and supplied by Professional MotorSport World Expo exhibitor, Hewland Engineering in the UK. The lower gear is suitable for tight, low-speed corners such as the Monte Carlo circuit, while the second is for high-speed straights and is accessed by a rocker switch, with shifts taking 150ms. “This is the only electric car in the world with a gearbox,” states Filloux. “It has two ratios with paddle shifts, commanded by pneumatic compressed air. It is a very simple system, but very effective. Hewland has big knowledge in this area so it was easy to work with them.”
As the project has progressed, further partners have come on board, with Michelin designing bespoke tires to meet the demands of high torque, aero load and rolling resistance, AP Racing providing the brakes, Koni and Sachs the dampers, OZ the wheels, FCI the connectors, and Motul Systems developing the transmission oil.
September 2010 saw testing begin at Magny-Cours with Jules Bianchi at the wheel, followed by the current development driver team of Alexandre Prémat and Michel Jourdain Jr on the Bugatti track at Le Mans. “We tested the car’s safety systems and analyzed its development. Following our tests at Magny-Cours and Le Mans, we ran more tests at a track close to Paris. There will be no more development of the car – it is finished and it is incredibly accomplished. We will use it do develop further solutions for other race cars, but this car is finished,” states Filloux.
With the development complete, Segula is now building a series of cars for the race series, with promotional races expected to begin in 2012. Ten races a year are planned, and following the 2013 season, other manufacturers will be invited to develop cars for the series, in the hope that they will further advance electric drivetrain technology.
Following testing, Filloux states that Prémat’s feedback was, “In terms of noise and sensation it was like the Audi R15, because it is a quiet diesel. The EF01 is quiet, but there is around 83dB of noise at full speed. Imagine 20 cars like this: they will make a lot of noise, but nothing like an F1 race. The feedback we get is that there is noise, but people can talk around the track and they find it pleasant. It makes a noise like a jet, but not as loud.”
Formulec hopes that the combination of low noise and zero emissions will enable city races to be planned for the future.
This feature is from August 2011