BMW Vision Driving Experience is a radical quad-motor test mule

Instead, the firm describes it as a one-off test rig on wheels, a moving laboratory used to hone technology being developed for all future Neue Klasse models in an extreme environment.

The development work being done with it is as relevant to the next single-motor, entry-level iX3 SUV as it will be to whatever M division’s engineers concoct for their electric offerings.

Perhaps because of the development work for which it has been created, until now the VDE has been cloaked in secrecy – and we’re not just talking about its camouflage wrap.

But the fact that BMW recently strapped me (thankfully tightly) into the passenger seat for a short – but very fast – ride shows that Munich now wants to showcase exactly why it has been created. Although Klingmann’s inability (or perhaps refusal) to share its power output indicates that the veil of secrecy isn’t fully lifted.

What BMW has confirmed is that the VDE is powered by four electric motors – one for each wheel – and can produce peak torque of 13,269lb ft.

And no, that’s not a typo. There isn’t an ofofficial power output, but given its ridiculous torque output, you can probably guess it’s pretty high. BMW hasn’t given any performance stats, either, but after my ride in it, I would say the 0-62mph time can be described as ‘brisk’.

Beyond the four motors, the other thing we have been told about are those fans. Five of them, in fact. BMW calls them impellers, and they serve to literally suck the car to the ground.

Each fan requires 50kW of energy to run, but combined they add around 1000kg of downforce without creating any drag, in turn allowing Klingmann to push even harder in corners.

All of that torque and downforce is really there to develop one small but very significant black box full of computer chips and loaded with software.

That would be BMW’s new Heart of Joy, the unusually named hardware and software stack that will unify the computer systems that run the powertrain and driving dynamics systems on future EVs into a single unit.

It’s the first time BMW has unified those systems, and the firm claims the system has been developed entirely in-house.

“The Heart of Joy will run all the key driving functions of the car,” says BMW driving dynamics expert Christian Thalmeier. “But to develop those, we need to push the technology.

Even production cars with only one electric motor will gain advantages from the work we’re doing on a car with four motors.”

It might seem like overkill to build a superpowerful, fan-laden development hack just to test a computer processing unit, but the idea is that if the Heart of Joy can handle anything the VDE can throw at it in the real world, it can handle pretty much anything.

So how does it work? Traditionally, the powertrain and driving dynamics systems have been separate units.

The powertrain system takes the inputs from your foot on the accelerator and sends that as a request to the powertrain, whether a combustion engine or a single or pair of electric motors.

Meanwhile, a separate driving dynamics unit receives inputs from the steering wheel and brakes, along with any other data the car’s sensors might get from the external environment.

Those two systems run in parallel, so there’s a small but potentially significant lag when they need to send data to each other, and there are limitations on how closely they can operate together.

The Heart of Joy unites those systems into a single unit that receives all those inputs in the same place, processes them simultaneously and then sends the information to up to four motors along with the brakes, steering and so on. BMW says it allows for communication that’s up to 10 times faster than that used on cars that were on sale in 2021.

That’s a big boost when trying to precisely modulate power and braking to best fit the conditions. But there are other benefits too. On most current EVs, friction braking is controlled by the driving dynamics unit while regeneration through the motors is the responsibility of the powertrain system.

That’s why you can sometimes feel an imbalance if you’re slowing using the regen and then need to apply the brakes.

“When recuperation is only done by the powertrain, you can’t use the whole potential of it,” says Thalmeier. “You need the driving dynamics system to work out how to enlarge the recuperation.”

He cites the example of a rearbiased car – yes, future BMW EVs will still be rear-driven or rear-biased – cornering at speed. “

When there’s a load change, you can only put a certain amount of longitudinal force on the tyres before the car becomes unstable,” he says.

“So to keep the car balanced, you have to take away either lateral or longitudinal force. Because you’re cornering and you can’t remove the lateral force, you have to reduce the recuperation to keep the car stable. But that’s not what we want: we want to add stability by recuperation.

“Now, though, we’re so quick at taking data from the sensors on the car about yaw rate, lateral and longitudinal acceleration and how stable the car is that we can change things. If it’s still stable, we can do a bit of recuperation, and when it gets unstable, it will be quickly reduced.”

There’s another benefit: the Heart of Joy can take your braking inputs and work out the most efficient way of stopping the car, which in most cases will be via the motor.

That increases the use of regen, which BMW claims makes the car up to 25% more efficient. Not a huge amount but a useful gain, given that the aim is for most drivers to not know whether it’s the brakes or the motor slowing their machine.

The Heart of Joy won’t just help when you’re slowing down your BMW, though: it will help you go faster.

Again, a combustion car has a single power source, so systems such as variable four-wheel drive or torque vectoring have to go through various mechanical systems to divide up that power.

But the new system can take power from one, two, three or four motors and continuously adjust where it’s sent to, keeping the car better balanced and more stable. Besides simply adding raw power, Thalmeier says adding motors will make a big difference to future Neue Klasse models.

“We’re influencing the driving dynamics,” he adds. “If you think of three electric motors with one on the front axle and two on the rear, you can help steer with the rear axle by making one wheel faster and the other slower.

"So you can make the car agile purely through running the electric motors at different speeds. Any existing actuator or rear-wheel steering system isn’t as quick as our new electric motors will be.”

Which brings us back to the passenger seat of the VDE, with Klingmann laughing as he jams the throttle and sends the machine down the straight of the BMW Spartanburg Performance Centre test track at something approaching warp speed.

It’s actually surprisingly comfortable inside, with comfy sports seats and a working version of BMW’s new iDrive system on the dashboard. Even in its test hacks, Munich does premium well.

But can you feel the Heart of Joy at work? Being honest, no, not really, but that’s in part because on a cold day in South Carolina tyre grip is limited and Klingmann confesses the road-legal rubber is the limiting factor.

But as my innards slowly settle once I’ve escaped the passenger seat, the performance of the Vision Driving Experience – and the systems underpinning it – is clear.

The closest comparison I can make is with a passenger ride in an electric rallycross supercar. Impressive, then. And it certainly whets the appetite for the potential of a quad-motor electric M3.

Why five impeller fans are needed to make the car suck

The BMW Vision Driving Experience’s five impeller fans are the car’s undoubted party piece, as demonstrated when its engineers fired them up for a demonstration when it was back in the garage.

For a comparison of how loud they are, imagine standing underneath the wing of an Airbus A380 when the pilot presses the start button. Essentially, they serve to stick the car to the ground, adding grip without creating aerodynamic downforce. But could they ever reach production?