Teams reveal innovative ideas ahead of season two | By Gary Watkins
Cars racing in the second season of the Formula E Championship will have one, two, three, four and five gears. That simple fact reveals the diversity of technical solutions chosen in reaction to new regulatory freedoms in the FIA’s electric vehicle series.
Formula E, which begins its second season in Beijing on October 17, will no longer be a one-make series. The Dallara-designed Spark SRT_01E chassis will remain, but the so-called manufacturers – Renault and seven of the 10 teams – have been free to develop their own powertrains under a five-year road map that will lead to the end of mid-race car swapping by 2018/19.
The challenge has not been simple. The teams have had to work within the constraints of the architecture of the Spark chassis, but the rules limit not only the energy they have available but, uniquely in international motor racing, the power, too. And then there was the question of the financial and technical resources available to the teams.
Reigning champion Nextev TCR from China, DS Virgin Racing and Renault (which supplies and backs the e.dams team) have been most innovative with their technical choices. Each chose a twin-motor solution and fewer gears than their rivals – just one for DS Virgin and Nextev, and two for Renault.
They have each opted for a high-torque motor package that has allowed them to do away with the need for a conventional gearbox. That saves weight and reduces any losses that come with changing gear.
DS Virgin Racing chief technical officer Sylvain Filippi suggested there are big gains to be made, even though the amount of energy from the Williams Advanced Engineering-supplied battery will remain at 28kW/h and maximum race power will be capped at 170kW, up from last year’s 150kW.
“In theory, if you are power-limited you can only go so far,” he said. “But in reality it is the opposite. Efficiency gains will translate into performance. The more efficient you are, the less lifting [coasting to conserve energy] you will have to do.
“That is why our philosophy has been to redesign the powertrain completely. We believe we have made significant gains in efficiency.”
Renault has chosen to err on the side of conservatism, by going for a two-gear set-up. “It is a question of risk assessment,” said Vincent Gaillardot, Renault’s Formula E programme manager. “In this first season of open powertrains, do you really want to go for a fully optimised solution in terms of weight and packaging and miss something that causes a bit of trouble, or do something where you have a bit more margin?”
The middle ground
The majority of teams will be using their own single motor set-ups and a multi-speed gearbox. They have linked up with a range of technical partners.
Andretti, for example, is collaborating with US-based Houston Mechatronics on the development of a new motor. Venturi, holder of the electric Land Speed Record, has produced its own that will also be used by Dragon Racing, while Mahindra has gone to McLaren with its own specifications for a revised unit.
Andretti team principal Roger Griffiths explained that a rule mandating that the motor must drive through a conventional mechanical differential “was the death of the two-motor solution for us”.
He added: “If you want your motor to be nice and small, with a low centre of gravity, you end up with a high-speed motor that needs more gears [because it has less torque].”
The Abt Schaeffler Audi Sport team was keeping details of its approach secret ahead of the last of three two-day Formula E tests scheduled for Donington Park in August, but the car is known to have a three-speed gearbox and is believed to have a single motor.
Upgrading the familiar
Team Aguri has opted to use the season-one package of the McLaren Electronic Systems single motor and a five-speed Hewland gearbox. Team principal Mark Preston, a former Arrows, McLaren and Super Aguri designer in Formula 1, argues that the gains that can be made with a shift to a new package can be outweighed by those available through optimising the existing equipment. “Power is not limited in any series using internal combustion,” he said, “but here we are limiting power and that means top speed. As long as you are not torque-limited out of the corners, you are not limited by the powertrain.
“Our basic calculation was that the races are most likely going to be the same number of laps and the energy from the battery is staying the same. If you look at the difference in the energy usage across the grid in season one, there was a bigger margin than the efficiency gains you are going to be able to make with the motor in season two.
“The good thing about Formula E is that we don’t know all the answers. Only time will tell who is right, and that is going to be fascinating.”
Villeneuve signs for Venturi
Formula E hit the headlines during the summer when it was announced that Jacques Villeneuve, 1997 F1 champion, would be racing next season for the Monégasque Venturi team. The deal should give the 44-year-old Canadian his first full season of racing since he comepeted in F1 for Sauber in 2005.
Villeneuve said he was embarking on a full programme after a nomadic post-F1 career in which he has raced sporadically in everything from NASCAR and sportscars through the World Rallycross Championship and Stock Car Brazil because “the opportunity was there”.
He added: “It has been fun going from ice racing to NASCAR and V8 Supercars to rallycross, but I have been looking for a full programme. It will be good to be in a full-time seat where you can work with the team through a proper test programme.”
Villeneuve will be paired with his former Peugeot sportscar team-mate Stéphane Sarrazin at Venturi, while Nick Heidfeld moves across to Mahindra to join Bruno Senna.