The name of the Opel/Vauxhall city car concept may have been drawn from Opel’s 1928 RAK2 prototype rocket powered car, but, with a tandem two-seater layout, it has more in common with the Renault Twizy electric two-seater and other 2011 Frankfurt Motor Show concepts such as the Audi urban concept or Volkswagen NILS.
The battery-electric concept is pitched at young drivers needing a stylish commuter vehicle. It has a claimed top speed of 75 mph (120 km/h) from the 37-kW electric motor, with a maximum range of around 60 mi (99 km) from the 5-kW·h lithium-ion battery pack, which has a claimed recharging time of 3 h.
Opel/Vauxhall claims that the vehicle can be completely free of greenhouse gas emissions because it could be recharged from a 500-W solar panel fitted to a garage roof, based on an average annual mileage of 6200 mi (10,000 km).
“There is an electric motor underneath the second seat and it drives the rear differential via a cardan drive,” said Dr. Stephan Gloger, the project leader for the RAKe concept, The choice of rear-wheel drive in such a small vehicle was determined because the designers thought it could be run easily with one motor, reckoned Gloger. “You have the possibility to have a 50/50 front-to-rear axle weight distribution by positioning the batteries in the right way. And we wanted this wider track at the front, enabling a very good turning circle and all that is easier with rear-wheel drive.”
The batteries are positioned low under the seats to keep the center of gravity low. “There are other solutions that we are also investigating due to the different forms of battery cells that are around,” said Gloger. “Finally we want to use the same battery cells as in the Ampera as that helps us to reduce costs.”
Opel/Vauxhall quotes a mass of 380 kg (838 lb) for the RAKe, which is around 3 m (9.8 ft) long and 119 cm (46.9 in) tall. The chassis layout uses a motorcycle-style rear swing arm between the rear wheels and a double wishbone suspension system at the front.
The inspiration for the tandem seating layout and powered tilting cockpit canopy was a glider or sailplane. “The seat is fixed as in a glider and the pedals and the steering wheel move; the driving feel is very similar to gliding,” said Gloger.
High-strength steel has been used for most of the car’s structure, “We developed that to have a very stiff and stabilized passenger cell like in a conventional car body,” continued Gloger. “It’s a steel spaceframe and the outer panels are made from recyclable plastics.”