Lotus
Evora 414E Hybrid Concept
The
Lotus Evora 414E Hybrid Concept, so-named because this latest
environmentally-focused technology demonstrator from Lotus Engineering produces
414 PS (306 kW) of power, promises breathtaking performance from a highly
efficient propulsion system. The concept showcases new developments in plug-in,
range-extended electric propulsion, new electronic technologies to enhance
driver involvement, the adaptability of the Lotus Versatile Vehicle
Architecture (VVA) that underpins the Lotus Evora 414E Hybrid and a dramatic
new roof system and interior concept from Lotus Design. Through all of these
aspects it ultimately demonstrates the exceptional ability of Lotus Engineering
to integrate and develop advanced technologies for exciting, efficient, high
performance niche vehicles.
The
range extended electric drive of the Lotus Evora 414E Hybrid consists of two
electric motors driving each of the rear wheels independently via single speed
geartrain, integrated into a common transmission housing, thus enabling torque
vectoring for stability control of the vehicle. Electrical power is stored in a
lithium polymer battery pack optimised for energy density, efficiency and high
power demand, mounted in the centre of the vehicle for stability and safety.
Additional range is provided by the Lotus Range Extender engine, an optimised
1.2 litre, three-cylinder engine, designed specifically for series hybrid
vehicles. The drivetrain is designed to combine astonishing performance with
efficient, low emissions driving.
Driver
involvement is enhanced by the incorporation of HALOsonic Internal and External
Electronic Sound Synthesis technologies from Lotus and Harman International,
which provide sound contouring within the cabin and improve pedestrian safety
outside the vehicle. Integrated with the HALOsonic technology, the Lotus Evora
414E Hybrid also showcases a brand new technology from Lotus Engineering, a
sports mode that simulates a 7 speed, paddle shift transmission that combines
exceptional driver involvement for a hybrid sports car and optimised energy
recuperation.
The
Lotus Evora 414E Hybrid has been designed to highlight Lotus' innovative
electric and hybrid vehicle technology without distracting from the pure
sportscar character of the Evora. The solution is innovative, instantly
recognizable, beautiful and sporty. It demonstrates Lotus DNA.
For
the Lotus Evora 414E Hybrid Concept, Lotus Engineering has developed a highly
efficient, high performance drivetrain system consisting of twin motors each
limited to providing 152 kW (207 PS/204 hp) of power and 400 Nm (295 lb-ft) of
torque to each wheel via independent, single speed, reduction transmissions
integrated into a single housing, enabling torque vectoring dynamic control of
the vehicle.
The
vehicle energy storage system is made up of the latest Lithium Polymer battery
chemistry providing 17 kWH energy storage capacity. The battery pack is
optimised for energy density, efficiency and high power demand, with over 100
kW discharge capability.
The
Lotus Range Extender engine provides 35 kW (48 PS/47 hp) of power at 3,500 rpm
via the integrated electrical generator and features an innovative architecture
comprising an aluminium monoblock construction, integrating the cylinder block,
cylinder head and exhaust manifold in one casting. This results in reduced
engine mass, assembly costs, package size and improved emissions and engine
durability. The engine uses an optimised two-valve, port-fuel injection
combustion system to reduce cost and mass and can be operated on alcohol-based
fuels and/or gasoline. The generator converts mechanical energy to electrical
energy to replenish the battery pack charge and provides additional vehicle
range in a small light weight package. The generator is also used as a motor to
start the range extender engine. The low mass of the range extender unit (85
kg) and compact package makes it ideal for the series hybrid drivetrain in the
Lotus Evora 414E Hybird.
The
Lotus Evora 414E Hybrid Concept provides less of a psychological step change
for people familiar with high performance cars compared to other electric and
hybrid sports cars. The car has a simulated paddle shift gear change offering
ultra quick gear changes reminiscent of a dual clutch transmission, while
actually single speed. This enhances the driver interaction with the vehicle
and provides a driving experience similar to current internal combustion engine
high performance sports cars. The Lotus Evora 414E Hybrid uses a column mounted
paddle shift to simulate the gear change and a synthesised engine sound changes
frequency with virtual gear selection. The drive torque is also modulated to
simulate a physical feeling of a gearshift jolt.
The
virtual gearshift simulation, like a conventional gearbox, is used to change
the driving characteristics and response of the vehicle. The most significant
aspect that this offers the driver is the ability to control the vehicle
deceleration by simulating engine braking through a virtual downshift in gears.
Unlike true engine braking, the Lotus system does not dissipate the energy of
the moving vehicle through internal engine friction but uses the electric
motors to regenerate the energy back into the battery. While many electric and
hybrid vehicles provide engine braking, this is generally at a fixed rate or
preselected rate. In some driving situations this can either be too aggressive,
slowing the vehicle unnecessarily, or too light, requiring additional braking
application. The Lotus system effectively allows the driver to select the
appropriate level of regeneration by simulating stepping down by one, two or
even three gears. The simulation of engine braking through both the gear noise
change and the retardation of the vehicle is fully intuitive to a driver
familiar with a conventional gearbox. The simulated gearchange capability can
be selected for greater driving involvement or switched off for more relaxed
driving.