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Pushing the Limits of Weight and Power Delivery in EV Hypercars

founded the company, is supporting us for the three-year design-and-
build phase of this car,” said Turton. “Not many companies are able to
do such a radical concept for such a long time in complete secret and
then reveal a fully working prototype at one of the biggest motoring
events in the world.”
Turton said that the car being shown at Goodwood is a high-
performance track-car concept with extremely low drag. “There’s no
front or rear wing, but instead, our downforce comes from an on-board
downforce-on-demand system, which is a fan-based downforce system
with over 80 horsepower sucking the car to the track,” he said. “What
it means is when you’re going at extremely high speed, your car is
low-drag, which reduces energy consumption. But you also get 100%
downforce from 0 mph. Hence, launching off the line, taking hairpins,
and going through high-speed corners, you’re getting peak downforce
at all times.”
The key to keeping the car compact and lightweight was integrating
Billionaire David McMurtry funded the development of his own the battery and chassis together, said Turton. “We’ve iterated to get the
hypercar. (Source: Renishaw) battery integrated right alongside the driver in the side part of the car
and underneath the driver’s legs, and that battery layout is patented
thermally controlled using dielectric oil — a technology also used to to our company,” he said. “In the battery pack, we’ve had extremely
keep the e-motor at operating temperatures that deliver the highest high-power cells, so we can charge and discharge at an extremely high
level of performance. rate. And because our car is so low-drag, we get the best of both worlds.
To further optimize packaging and weight, the battery management You’re getting the high power for acceleration and charging and the low
unit sits alongside the modules, with the power distribution unit drag for speed and range. The battery is over 800 V.”
integrated into the battery. An integrated power unit acts as a DC/DC
converter for the vehicle’s 12-V system, reducing weight by removing
the need for a separate alternator and on-board battery charger.
An Artura driver can adjust how the electric motor is deployed to
prioritize range or power or choose to shut off the internal combustion
engine for silent running. Energy harvesting is achieved purely from
the combustion engine to maintain brake pedal feel, yet the battery can
be charged from low to 80% full within minutes under normal driving
conditions.
Ian Howshall, a global product manager at McLaren, explained that
the complete architecture of the car is brand new to accommodate the
high-voltage battery required. He said that the fundamental changes
were moving from large wiring harnesses to Ethernet and using
decentralized electronic control systems, with separate domain-based
electronic control units for different domains. These changes help
minimize weight and improve critical signal response times.
NO-RULES TRACK CAR
McMurtry Automotive exhibited its experimental, fully electric track-
car concept, the McMurtry Spéirling. The company said it had created
the ultimate no-rules track car by exploring the route that uninhibited
technical evolution would have taken from the golden age of racing to
shape the motorsport of today.
“Our aim is to change perceptions on small cars, so we want to pro-
duce extremely small, fast, exciting, and efficient electric cars,” David
Turton, a mechanical design engineer at the company, told me. “Today,
we’re unveiling the no-rules track car, which is akin to a hypercar to The McMurtry Spéirling is supposed to be the ultimate “no-rules
demonstrate the technologies that are required to excite people about track car,” exploring the route that uninhibited technical evolution
electric cars in this form factor.” can take. (Source: Nitin Dahad)
The development of the car is funded by Irish billionaire and
inventor David McMurtry, who founded Renishaw, a precision A clear message from most of the engineers and product managers
metrology company. His backstory is that he initially trained as an was that pushing the limits for experimental track hypercars, or even
apprentice in the aerospace industry in the U.K. and then became those going into production, paves the way for commercial application
the youngest-ever assistant chief of engine design for all Rolls-Royce in road cars and elsewhere.
engines manufactured in Filton, Bristol. While there, he invented As Turton said, “Our long-term goal is to produce road cars, but it’s
the 3D touch-trigger probe to solve a measurement problem faced important for us to demonstrate something that’s really exciting and
with the Olympus engines for the supersonic Concorde aircraft and never been seen before.” ■
then founded Renishaw Electrical in 1973 with John Deer to commer-
cialize the product. Nitin Dahad is editor-in-chief of Embedded. This article originally
“We’re in a very fortunate position that Sir David McMurtry, who appeared on EE Times.

www.eetimes.eu | SEPTEMBER 2021