Designed by Ariel Electric Ltd, part of the Ariel Group, HIPERCAR (standing for High Performance Carbon Reduction) is shown for the first time with production intent bodywork and as a fully operational prototype. As with other Ariel vehicles the focus of HIPERCAR is on extreme performance, light weight, agility and usability, now coupled with zero emissions plus the option of a lightweight turbine range extender. To be made alongside the Atom and Nomad the HIPERCAR, with actual model name still to be finalised, is the first vehicle on Ariel’s path to zero emissions.
To be available in four wheel drive and two wheel drive variants the 880kw/1180bhp lightweight HIPERCAR offers staggering performance with 0 - 60 times of 2.09 seconds and 0 – 100 mph in 4.4 seconds. With full torque vectoring these times will be improved so that sub 2 second times to 60mph and sub 4 seconds to 100mph are possible.
Development of the car and associated technologies, which has been grant aided by the UK Government through Innovate UK, the Advanced Propulsion Centre and Niche Vehicle Network, is based around cutting edge EV technology all developed in the UK and the car will be built in Somerset, England by Ariel. The vehicle showcases what the UK can achieve in the highly competitive and fast changing EV sector with all key HIPERCAR components – chassis, body, motor, gearbox, battery, power electronics, range extender, driveline and mechanical components – developed by Ariel and other British companies.
Said Simon Saunders, Director of Ariel, “We still have a lot of testing, tuning and detail work to carry out over the next year or two prior to production, but what we are showing today is essentially what we intend to produce. Developing another of the world’s fastest and technically advanced cars is important for us but anchoring the technology that has been developed in this country and building a British EV supply chain is vital for the UK economy. HIPERCAR isn’t just a milestone in vehicle design, it’s a demonstration of what we can do as an industry.”
Vehicle Overview
HIPERCAR is a full EV (Electric Vehicle) and will be available as 4 wheel drive or 2 wheel rear drive. The car is based around a lightweight aluminium, bonded chassis structure with aluminium front and rear subframes and full carbon fibre body.
Power is from a Cosworth 800 Volt, 62kWh lithium-ion, cooled and heated battery pack. Electric range, without range extender, is 150 miles on WLTP cycle. The battery can be charged at home or via a conventional charging station if required.
The car will feature the option of a Cosworth 35kW CatGen (Catalytic Generator) turbine range extender to charge the battery on the move, negating any range anxiety issues and making the vehicle independent of any charging infrastructure.
Drive is by inboard Equipmake APM motors, one per wheel, with integral inverters and single speed step down gearboxes direct to driven wheels. Each individual motor develops 220kW (295bhp) and 450Nm (332 ft lb) of torque.
In 4 wheel drive total power is 880 kW (1,180bhp) and in 2 wheel drive form 440kW (590bhp). Total torque is 1,800 Nm (1327 ft lb) at motor in the 4 wheel drive HIPERCAR and 900Nm (664 ft lb) at motor in the 2 wheel drive car.
Production vehicle weight will be 1500 kilos for the 4 wheel drive car and sub 1400 kilos for the two wheel drive car, underlining the ultra low weight of the car and Ariel’s ethos of performance through lightweighting.
HIPERCAR has been designed to pass EUSSTA (European Small Series Type Approval), ADR (Australian Design Rules) and conform to ISO26262 Functional Safety requirements.
Vehicle Performance
0 – 60 mph 2.09 seconds
0 – 100 mph 4.42 seconds
60 – 120mph 3.51 seconds
Top speed 155 mph (Limited)
Final pricing to be announced.
Said Simon Saunders, “The price of the four wheel drive car with range extender on the road in the UK, with all taxes, will be under one million pounds and although expensive we’re determined to make it value for money, like all Ariel products. Production HIPERCARS are around two years away but with a current 28 month lead time for an Atom it’s about the same time. HIPERCAR will be manufactured alongside the Atom and Nomad with the same unique care and individual build quality that goes into every single Ariel.”
Ariel already have orders for the car and are now taking further deposits.
Vehicle Detail
Chassis
The all new G2 HIPERCAR chassis is a laser cut and CNC folded, bonded aluminium monocoque. Removable aluminium front and rear subframes are connected to the structure by machined aluminium interfaces, providing crush structure and mechanical mount points. With excellent torsional and beam stiffness, the all-aluminium structure exceeds all Type Approval requirements for front, offset, side and pole impacts.
The sealed battery pack, integrated as low as possible under the floor and in the centre tunnel of the chassis to lower and centralise centre of gravity, is mounted within the wheelbase to ensure security. Additional underbody and battery protection is achieved by using a ‘HyLight’ multi-material battery casing, specially developed for HIPERCAR. The lightweight casing incorporates a patented bonded aluminium/composite sandwich which gives excellent EMC screening, is puncture resistant and passes UNECE safety testing.
Body
While recognisably an Ariel, HIPERCAR features a first for the company with a fully enclosed body and forward tilting, butterfly doors. Doors are electronically released and closed with opening aided by balanced gas struts. Bodywork will be full carbon in production, as seen in the central body shell, although the prototype currently has some 3D printed panels for final testing and detail design purposes.
Much of the appearance of HIPERCAR has been driven by aerodynamic consideration for drag efficiency, balance and meeting the complex requirements of the multiple cooling systems. Working with TotalSim of Brackley and using the newly developed BRAMBLE CFD (Computational Fluid Dynamics) system developed with Ariel, the companies have spent thousands of hours on aerodynamic development. Each part of the car, both body and underbody, is the result of painstaking attention to detail and serves a purpose. As examples the fins on the front wings reduce drag on the mirrors, the roof scoop supplies air to the turbine range extender and the ‘Sharks Fins’ at the rear aid stability and cornering.
The two seat cabin will allow comfortable accommodation for 98%tile+ driver and passenger (6’4”+). TFT screens provide information but due to the extreme performance of the car overhead push buttons and steering wheel controls have been favoured over touch screen functions. Final design of the interior is yet to be shown but is described by Ariel as ‘Plush Le Mans’
Suspension, Steering, Brakes, Wheels and Tyres
With geometry designed by Richard Hurdwell, who also designed the Atom 4 geometry, HIPERCAR suspension is by unequal length double wishbones all round, machined from aluminium for ultimate precision while maximising strength and minimising weight. Adjustable roll bars are fitted front and rear. Adaptive dampers, made specifically for HIPERCAR by Bilstein UK have independent adjustment of compression and rebound. Designed to maximise on road performance or track use the dynamic driving experience will reflect Ariel’s reputation for engaging and entertaining the driver.
Steering is by a bespoke power assisted system, developed specifically for HIPERCAR, with Ariel placing feel and feedback at the top of the priority list. A 330mm steering wheel, mounted on an adjustable reach and rake column, gives 2.75 turns lock to lock.
Foundation braking is taken care of by an AP Racing braking system comprising six piston calipers on the front with 370x32mm ventilated and grooved discs, with four piston calipers and 328x30mm ventilated and grooved discs at the rear. Operated by a billet machined pedal with an adjustable ratio via an electric servo the assisted system is again being tuned to provide feel and feedback, another essential element in creating the Ariel driving experience. An electric park brake is fitted.
In addition to the foundation braking a regenerative braking system can be turned on and off, depending on use, with adjustments made to the amount of regen. Driver involvement remains paramount to the Ariel experience. Said Jim McKechnie, Ariel’s Chief Engineer, “Like the Atom and Nomad the HIPERCAR is about the passion for driving. Due to the complexity of the car and the amount of power available we do have many systems on the car to aid the driver. However it’s important to us that he or she not only remains in control of these systems but that the driver has a full interaction with the car when they want it.”
HIPERCAR currently features adjustable traction control and the production car will have adjustable torque vectoring in order to provide maximum power and grip to each driven wheel when required. The full torque vectoring, linked to other vehicle systems will have the ability to power driven wheels at different rates to further improve traction and, for instance, when cornering to improve performance yet further.
The huge power and torque of HIPERCAR is delivered to the road through Michelin Pilot Cup2 tyres in 265/35/20 size on the front and 325/30/21 on the rear with the option of the phenomenal Michelin Cup 2R tyres for even more grip. The lightweight 9J front and 12.5J rear forged wheels on the current car will be replaced by bespoke carbon wheels on the production car saving further unsprung weight.
Motor, Gearbox, Power electronics
The 4WD HIPERCAR has four Equipmake APM200 220kW (295bhp) motors, one per wheel, mounted inboard back to back, two to each axle. Developed during the HIPERCAR project the motor features a revolutionary radial rotor architecture with magnets arranged around the outside of the rotor. This makes the motor extremely power dense and reduces magnetic material by around 25%, saving weight and use of rare earth material.
Integrated into each unit is a single speed, epicyclic 5.43:1 gearbox with helical cut gears and asymmetric tooth profiles. An inverter and power electronics are an integral part of each motor. The close coupling of the inverter with the motor decreases transmission losses in the interconnecting cabling, reduces weight and improves EMC performance (Electromagnetic Compatibility).
A complete motor, gearbox and inverter assembly weighs only 57 kilos, contributing to the lightweighting demands throughout the vehicle.
Battery
The Cosworth battery pack developed specifically for HIPERCAR has a maximum voltage 800 volts with a nominal of 690 volts. Using 5,760 Murata battery cells the pack is made up of 32 modules, each with 180 x 18650 lithium-ion cells. The high-power density cells facilitate a peak current draw of 1,450 Amps.
In order to overcome the challenges of thermal management in the pack, particularly in the track use required by Ariel, a unique and patented liquid-cooled system was developed. The system feeds refrigerated, or heated, water-glycol coolant directly and evenly to every single cell in the pack, monitored by temperature sensors throughout the pack. Sensor information is used to actively control the demand for heating or cooling as required.
Each of the battery modules within the pack has a local data capture board monitoring and managing each parallel group of cells. This information is broadcast, along with the 360 measurements taken throughout the battery pack, into one of four sub-master units. These communicate with the battery master controller coordinating all information and making key decisions regarding parameters such as power limits, cooling requirements and current balancing. The master controller also has responsibility for contactor control, as well as interfacing with the powertrain controller and vehicle’s 12 volt electrical systems.
CatGen Micro Turbine Range Extender
The optional Cosworth range extender features a micro-turbine powered by a catalytic exothermic reaction. Running at a fixed 120,000 rpm to optimise efficiency it generates 35kW of continuous electrical power when required to maintain battery state of charge. The unit is automatically switched on and off as needed via the battery management system, or by manual override. Weighing less than 50kg and with only one moving part (the turbine), the range extender is significantly smaller and lighter than any piston or rotary engine alternative. Designed to run on a variety of fuels the unit has negligible emission levels when currently running with gasoline and will be hydrogen capable in the future.
Charging System
In addition to the range extender, provision has also been made on HIPERCAR to charge from home or the existing charging infrastructure and is compatible with CHAdeMO and Type 2 hardware. Ariel realised that it may be some years before the charging infrastructure is capable of supporting an 800V EV and Cosworth have implemented an innovative approach to address the problem. The novel split charger system allows the high voltage HIPERCAR to charge using existing industry standard facilities designed for less than 500V.
With approximately 1MW of power available between the four wheels the ability to recapture kinetic energy when off throttle is significant. Working within the capability of the battery system and vehicle stability, recharging of battery pack via regen is carried out by the wheel motors making HIPERCAR as efficient as possible.
Cooling and HVAC
HIPERCAR features a multi-circuit heated and cooled water-glycol system for cabin HVAC, battery pack, power electronics and drivetrain. With varying temperature requirements from battery, motor, inverters, range extender and cabin, there are 8 separate cooling circuits feeding 10 systems on the car. The complex cooling architecture requires highly sophisticated control to ensure that all systems receive the specific attention demanded by their respective operating conditions across a wide range of drive cycles, from road to track.
Tom Mclaren, Lead Engineer on HIPERCAR said, “Our most difficult requirement was giving HIPERCAR track capability. This was vital for an Ariel and is a measure of any sports car, but heat generation in the battery went up by a factor of 10 when compared with very hard road driving. The cooled battery pack solved the problem which has pushed the technology to give us what we needed”
The thermal management system has been designed to operate in a temperature range of minus 20 degrees to 45 degrees ambient (Centigrade). The cabin features heating and air conditioning – another first for Ariel, where previously fresh air has not been an issue.
“We’ve done serious amounts of physical testing with HIPERCAR Partners including GKN Driveline and Johnson Matthey,” said Simon Saunders, “this has ranged from WLTP and abuse loads to thousands of non-stop laps of race circuits on test rigs working 24 hours a day. HIPERCAR has been through climatic chamber testing, shaker rigs, NVH and EMC testing with multiple computer simulations for aerodynamics with TotalSim plus FEA and safety simulations with Tecosim. We have had various test mules running for over three years testing different cell configurations, battery packs, cooling and control systems. The Cosworth range extender and the Equipmake motors each represent a decade of development. This is a very serious car with a very serious amount of development work behind it. There’s more to go, but for Ariel the HIPERCAR proves that EVs can not only be extraordinarily fast at the same time as being environmentally friendly, but that they can also be fun. That’s something that’s really important to us and to our customers. After all our Ariel motto is SERIOUS FUN and I think HIPERCAR well and truly underlines that.”
The Ariel HIPERCAR will be shown on the Government Pavilion at LCV (Low Carbon Vehicle) Show at Millbrook Proving Ground on 7th and 8th September.
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For further information please contact Simon Saunders at Ariel Motor Company on 01460 78817