Big-banger Porsche EV on the way

The hints are there that Porsche is planning a series of ultra-powerful electric SUVs after it leaked news of a four-motor prototype on its own website.

The upcoming Porsche Taycan Turbo S (pictured) already holds the unofficial EV production car record on the Nurburgring’s Nordschleife circuit, and Porsche has now moved on to something else.

Porsche has admitted to testing a four-motor SUV from its Porsche Engineering consultancy and is expected to launch a 520kW Macan Turbo S based on the same J1 platform as the Taycan in 2021, but insists the quad-motor system is aimed at pinpoint powertrain accuracy instead of outright performance.

Dubbed e-SUV drive, the tested system is designed to deliver precise torque to each wheel for every situation, all within milliseconds.

Suitable for a range of motor sizes, it’s based around Porsche Engineering software that has been developed over the past two winters.

Porsche has yet to provide feedback on which of its cars could be first to receive the software and the four-motor hardware, though its development by Porsche Engineering hints that it could even be available for other OEMs under licence.

Porsche insists the only place this kind of technology has been seen before is on the Mars rovers, but the torque control system has now been developed to suit production SUVs.

“We had to develop a lot of it from the ground up,” Porsche Engineering’s Function Development team leader Dr Martin Rezac said.

“The task, in short, was essentially driving stability by app. This makes the vehicle noticeably more stable, even for the passenger,” he said.

The main challenge was that the system could not demand additional sensor technologies, but piggyback onto existing electronics platforms and control devices.

“It’s almost as if you had a separate gas pedal for each axle or wheel,” Porsche Engineering’s Ulf Hintze said.

“In a conventional all-wheel drive vehicle; there is just one engine at work, whose power is distributed to the axles through a central differential.

“As a rule, the torque ratio is fixed: one-third up front and two-thirds in the back, for instance. The ratio can, in theory, be changed, but additional mechanical gadgetry is required for that (multi-plate friction clutch), and it works rather sluggishly.

“In an electric vehicle, by contrast, the torque is purely electronically controlled, which works considerably faster than mechanical clutches. Every millisecond, intelligent software distributes the forces in such a way that the vehicle always behaves neutrally.

“And Porsche Engineering developed just such a torque control system for all-wheel drive SUVs. The software can be used for different constellations and motor configurations – for other electric vehicle types as well, of course.”

It’s governed by a Driving State Observer (which Porsche Engineering quickly dubbed The Observer) to monitor everything from the grip in the road to the yaw to the steering angle and the throttle angle.

It detects deviations, like understeer, oversteer or all-wheel drifting, and instructs the electric motors to intervene individually by accelerating or regenerating to slow each wheel down.

“While a conventional ESP system only brakes, in an electric vehicle the individual wheels can be accelerated as well,” Rezac said.

“This ‘pulls’ the vehicle back onto the right track without losing speed. The intervention is also less jerky than in a hydraulic ESP system; the typical juddering familiar from anti-lock brake systems is omitted.

“The development of the vehicle observer was the biggest challenge,” he said.