Yamaha has teamed up with Gordon
Murray and Zytek to deliver a concept electric vehicle with a difference.
A few years ago, former McLaren technical
director Gordon Murray received a lot of media attention for his then newly
formed company, Gordon Murray Design, and its innovative iStream manufacturing
process – essentially a total rethink in terms of vehicle production and the
use of high-volume materials. And then things went rather quiet. Until now.
The
motiv.e, which weighs just 730kg, boasts an electric drivetrain that delivers
up to 896Nm of torque
The British organization, with its T.25 and
T.27 vehicle concepts, has teamed up with Yamaha Motor Company to create
something quite different: the Motiv.e city car, which makes use of iStream in
order to tick a lot of urban mobility needs, says its makers.
Harnessing Yamaha’s experience in two-,
three- and four-wheel drive technology, Motiv.e weighs just 730kg – and
amazingly that includes the 8.8kWh lithium-ion battery pack that provides power
to an electric motor that’s rated at 12kW continuous and 25kW peak. Such a
combination means Motiv.e, which also has a single-speed transmission
channeling power to the rear wheels, can cover 160km (100 miles) in the real
world before needing a charge, which Yamaha says takes only three hours from a
domestic socket to go from battery empty back to full. On a quick-charge unit,
only one hour is needed to replenish the pack.
The e-powertrain’s huge 658Nm of continuous
torque, that then spikes up to 896Nm for peak output (yes, you’ve read that
right), means that the Yamaha EV concept, which looks like a sleeker, even more
compact Smart FourTwo, takes 15 seconds to hit 100km/h (62mph) from standstill
before mustering a maximum speed of 105km/h (65mph).
Tough Targets
Much of Motiv.e’s electric drive has been
developed by Zytek, which for this project employed a range of new design
approaches to minimize the cost, weight and size of the powertrain, while
maximizing important aspects such as performance and range.
“Yamaha wanted the vehicle to reflect the
company’s reputation for outstanding engines,” explains Neil Cheeseman, Zytek’s
engineering program manager, when asked about the project. “Integrating this
into an electric vehicle has driven excellence in performance and driveability,
as well as in weight reduction and efficiency, building on the potential of
iStream to deliver an agile drivers’ car, as well as maximizing the range.”
Unlike
the three seat layout with a central driving position similar to Murray’s
superlative McLaren F1, Yamaha decided to make the Motiv a two seater, using
Murray patented thin shell composite seats.
The Zytek e-motor, which has been designed
to rev to 25,000rpm, is paired with a singlespeed reduction gearbox from Vocis,
while a new-generation electric vehicle control module provides the interface
between the powertrain and the rest of the vehicle. Motiv.e’s low-cost power
electronics are manufactured in high volumes by Zytek’s partner and now owner,
Continental.
With the concept being so light, it’s no
surprise to learn that individual key powertrain subsystems are not heavy,
bulky components: “The motor weighs just 13kg,” adds Cheeseman, “the gearbox
only 11kg. These are components that you can pick up with one hand.” What’s
more, the inverter’s only 7.5kg in mass.
Motiv.e’s chassis comes straight from
Murray’s iStream manufacturing process, which during the first stage typically
sees the powertrain, wiring harnesses, brakes, suspension and all other major
components added directly onto the chassis prior to the body panels being
fitted. The body panels are then delivered to the line pre-painted. They are
then married to the completed chassis near the end of the assembly process,
helping to reduce the paint damage that’s normally associated with a standard
assembly line. All external panels can then be mechanically fixed to the
chassis.
Advantages of the process, says Murray, is
that the chassis can be scaled in size for different products, with each new
design requiring only low-cost tooling and software changes. Such flexibility
means that the chassis can be used as a standard platform to deliver different
vehicle types and model variants.
The
MOTIV.e design reflects Yamaha's rich heritage in high quality lifestyle
products while introducing a technical and dynamic shape which is inspired by
Yamaha Motor's Motorcycle products.
And if that’s not impressive enough, Murray
says that by replacing metal presses with machines for bending, welding and the
simplified overall assembly process, the manufacturing plant can be designed to
be 20% the size of a conventional factory. This could reduce capital investment
in the assembly plant by approximately 80%.
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Vital
Statistics
·
Motor: Zytek developed; 15kW continuous, 25kW
peak
·
Torque: 658Nm continuous, 896Nm peak
·
Battery: lithium-ion, 8.8kWh in total
·
Transmission: Vocis developed; single-speed,
rear-wheel drive
·
Chassis: isteam manufacturing process; up
cycled plastic panels for the body of the
vehicle
·
Power electronics: continental developed and
produced
·
Top speed:105km/h (65 mph)
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