The unveiling of an ultra-high performance sports car (claimed 0-160 kph in 3.8 s) at a major low-carbon vehicles' event might seem unlikely, but that is where project partners Ariel Motor Co., Delta Motorsport, and Equipmake, chose to launch their Hipercar prototype.
The name translates as HIgh PERformance CArbon Reduction, a project that has the blessing of the U.K. government via Innovate U.K., the country’s innovation agency, which has contributed a £2 million grant.
Hipercar, with mini-turbine range extender, will be built by Ariel, manufacturer of high performance niche models including the Atom. It aims to use the vehicle as a high-profile launch pad for technology applicable to other niche, medium and ultimately high volume production.
Ariel's Director, Simon Saunders, told Automotive Engineering: "One of the most interesting things about Hipercar is that you can now go faster, greener. New technologies will not only allow our, and future, cars to be more environmentally friendly, meet U.K. and global emissions targets, but will also outperform a conventional ICE car. It's good news for air quality, its good news for the economy but above all it's good news for our customers!"
At the U.K.’s Cenex-LCV Expo 2017 at Millbrook Proving Ground, Saunders revealed the car’s rolling chassis with its main components installed, with the aim of showing the advanced technology. Unveiling of the complete bodywork will come later—the opposite of most new vehicle reveals which usually put styling above technology.
The platform unveiling came at the completion of the initial R&D phase of the car’s development. Now, supported by a further £6 million grant from the Advanced Propulsion Center, the three partners will be joined by GKN Hybrid Drive, Johnson Matthey, and Semikron for further testing, development and, ultimately, production in 2020.
Hipercar has an inboard motor for each driven wheel (there will be AWD and 2WD versions) with integrated gearbox and inverter. Each motor will deliver 220 kW (295 hp) and 450 N·m (332 lb·ft) so in AWD form, power output will be 880 kW (1180 hp). Claimed peak torque is 1800 Nm (1327 lb·ft) at the motor and 9900 N·m (7302 lb·ft) at the wheels. Motor, gearbox and inverter assembly weigh a total of 57 kg (126 lb).
It has a micro-turbine (gasoline fueled) range extender producing 35 kW (47 hp). The AWD battery pack uses liquid cooled lithium ion cells with 42 kW·h capacity and the 2WD a 56 kW·h pack.
The APM200 motor selected for Hipercar has been developed by Equipmake working with software specialist Motor Design Limited. It has novel rotor architecture in an aluminum housing having a diameter of 318 mm (12.5 in) and weighing 40 kg (88 lb). Magnets are positioned “like the spokes of a wheel” around the outside of the rotor instead of in a more conventional V shape on the outside of the rotor laminations. The result is described by Equipmake as producing an increase in torque density of some 25% compared to a conventional rotor. Direct cooling of the magnets is via water glycol.
The single-speed gearbox with reduction ratio of 5.5:1 is epicyclic and weighs 9kg (20 lb).Its cooling system is shared with the motor. Inverters are positioned above, and connected to, the motor.
Delta Motorsport has developed two battery systems (AWD and 2WD versions) for the car. The AWD has a peak voltage of 750V. Maximum power capability is cited as “over 1500 kW" (2011 hp).
Micro turbine with recuperator
The micro-turbine is also a Delta Motorsport development, having a 35-kW (47-hp) output, running at a fixed 120,000 rpm that generates power to maintain battery state of charge. Battery management automatically selects the turbine as required but there is also a manual override. A gas-turbine solution was chosen partly for is light weight of less than 50 kg (110 lb). A recuperator reduces emissions, particularly NOx, stated Delta Motorsport engineers.
Computational fluid dynamics (CFD) techniques used for F1 race cars have been used by specialist TotalSim to meet required drag, downforce and cooling systems’ requirements.
The car has a folded and bonded aluminum chassis, and removable front and rear subframes with billet machined and anodized aluminum interfaces. Unequal length aluminum double wishbones are used. Carbon composite wheels (an option for production cars) are fitted with Michelin Pilot Cup Sport 2 tires.
The car's electrical architecture uses high and low voltage systems linked by multiple CAN networks.
Each seat weighs 9 kg and is made of carbon fiber tube; they recline and are pressure mapped. A version of those shown on the prototype will be used in production vehicles.
The Hipercar will receive a model name later in the development program. It will need to be particularly descriptive. “This is the first true electric supercar that will cross continents, drive to town and lap a racetrack,” said Saunders.Continue reading »