Paul Drayson, Managing Partner at Drayson Racing Technologies of Kidlington, U.K., is looking to make a statement with his new Lola/Drayson B12/69EV racecar, a 200-plus-mph (322-plus-km/h) electric technology demonstrator.
“Even though the electric car market is struggling a bit right now, it seems certain that electric cars are going to be an important part of the car business, so if motor racing wants to remain relevant it needs to go electric,” he said. “And electric racing will provide a new opportunity to get the general public to appreciate and understand the benefits of electric cars.”
“At the moment, we haven’t seen electric racing yet, but it’s the only way to judge the ultimate performance of electric cars,” the British peer and former Minister of Science and Innovation continued. “After all, we don’t judge the ultimate performance of internal-combustion cars by what a Ford Focus can do.”
“Of course, we’re not doing this for charity,” he added. “We see it as a good business opportunity.”
Low carbon racing
The Lola/Drayson electric racecar was introduced at the recent 2011 Motorsport Industry Association’s (MIA) Low Carbon Racing Conference in Birmingham. Drayson, who is president of the MIA, hopes that a derivative of the car will be entered in the FIA Formula E series for electric racecars, which begins in 2013.
The fact that “it will be just as fast as conventional racecars” should come as no surprise, he noted, because the car exploits “the know-how that the U.K. motorsport industry has to produce something quite extraordinary.” The prototype e-racer showcases innovative technologies including active aerodynamics, wireless charging, electrical regenerative damping, and perhaps structural battery technology “making it one of the most innovative clean-tech motorsport projects in the world.”
“The electric B12 is a prototype whereby we can test many of the systems and new ideas we expect to use on the racetrack,” he said. “To build very high-performance electric cars, you really need to get running experience on the track where the stresses and strains are quite different than those faced by a road car.”
Such trials are particularly important for learning how to optimize high-power electric motors for racing, “which is exactly parallel to what we had to do with conventional racecars powered by internal-combustion engines.”
Track testing will begin later this year.
“The fact that the cars are to be raced on streets right in the heart of cities makes it more relevant to people, and that’s what motorsport has to target,” he emphasized. “The real advantage of electric racing is that it can change people’s perceptions about what an electric car can do.
“It also spurs innovation, which is what motor racing has always done—accelerate the development of new technologies, which then come down to road cars a few years later,” Drayson continued.
Despite the new car’s high maximum speed, electric drive technology is nowhere near competitive in terms of range, so the Formula E race format will run four 15-minute heats with a half-hour battery-recharging period in between. The B12/69EV itself is designed to operate for 20 minutes at maximum power, he said.
Drayson believes that Formula E’s nearly open rulebook has the potential to revolutionize racing: “The rulebook imposes no limit on power and is completely open regarding aerodynamics.” Its main stipulations are that the vehicle fit into “a box with specified dimensions and that battery weight should not exceed 300 kg.”
“The car, for example, has wireless charging,” he said. “No power cable is needed to charge the car, something that’s sure to come to road cars in the not-too-distant future.”
The electric racecar project began at the start of last year in collaboration with Lola Cars International, a leading chassis designer based in Huntingdon, U.K. Cooperation with Lola's participation is important, Drayson stated, because the company brings with it its extensive experience in high-performance chassis technology and its recent developments in active aerodynamics.
The new electric racer is based on today’s Lola LMP1 B12/60 Le Mans Prototype chassis. At 1085 kg (2392 lb), with driver, the modified car weighs somewhat more than the current 900-kg (1984-lb) LMP1 car.
In wind-tunnel experiments, Lola engineers have developed moveable aerodynamic surfaces on the front wheel screen flaps, the rear panel, as well as the rear wing, he reported. Electric actuators under the driver’s control adjust position of the surfaces to boost downforce or shed drag as needed. The driver can, for example, opt to cut drag on the straights to place less strain on the battery by lowering the wing.
Although the degree of drag reduction “is limited because we don’t want to upset balance of car, it is quite significant,” he said, noting that the use of forward-mounted aerodynamic surfaces “means that it takes a finite amount of time for the airflow to reattach and alter the drag characteristics.” This is a new effect that the drivers will have to learn how to control correctly.
The company's 4X2-640 electric drivetrain, which comprises four asynchronous pancake motors affixed to the rear axle, produces 850 peak hp (633 kW). The axial-flux motors were supplied by YASA Motors, a start-up firm that was spun out of nearby Oxford University.
“The high power-to-weight ratio of the motors pose some cooling challenges, which led us to use dual water and air circuits for cooling,” he said.
The car’s 300-kg (661-lb) battery pack, which was manufactured by Mavizen of Gerrards Cross, U.K., consists of two inline-mounted modules containing lithium-ion nanophosphate cells from A123 Systems of Waltham, MA. The battery units, which are embedded in the structure itself to improve weight efficiency, reportedly deliver 60 kW·h of energy at 700 V (maximum).
The battery power feeds into four inverters provided by Rinehart Motion Systems of Wilsonville, OR. The B12/69EV’s battery control technology was supplied by Cosworth of Cambridge, U.K., which provided the original system for the standard LMP1 B12/60 chassis.
Together, the electric powertrain can send the prototype EV from 0 to 60 mph (97 km/h) in 3 s, and 0 to 100 mph (161 km/h) in 5.1 s.
Structural batteries could cut weight
Drayson said that his team is also experimenting with structural battery technology from U.K.-based BAE Systems, which could both save weight and extend energy storage capacity in future versions of the car.
“The layers of the carbon-fiber composites not only provide load-bearing structure but operate as an energy storage device,” he explained. The integration of the two functions improves volumetric and energy efficiency as well as delivering greater flexibility in design and mass distribution.
Right now the development team is working to incorporate structural battery capability into the rear wing.
The Warwick Manufacturing Group (WMG) at Warwick University, working in cooperation with Lola, will provide new recycled carbon fiber-composite body panel technology.
Battery charging is accomplished in the pit garage using coils in the car floor that are powered inductively without contact by charge pads below. The wireless system is made by Qualcomm Halo, a spin-off from the University of New Zealand. The current charging system is static, but eventually the technology should be able to power up the batteries dynamically on the track.
Another innovation is the application of electrical regenerative damping technology from Canada-based Multimatic of Markham, Ontario. These suspension dampers generate energy when the driving-over-road undulations are stored in a capacitor for later use. “The regenerative dampers should produce a small but meaningful return,” Drayson said.
During his extensive travels, Drayson has heard numerous older race enthusiasts question whether electric racing is truly viable, citing issues including the lack of the traditional engine roar of the racetrack and the like.
“But younger people, especially those in regions without an established motorsport tradition such as India, China, and the Middle East, don’t ask those questions,” he counters. “They know that electric car technology is the future, and they want to take part in it.”