Lars Kern is having a great time. I am too. I’m sitting right seat with Porsche’s ace development driver as he romps the Panamera Turbo E-Hybrid over every single curb and rumble strip on Seville’s Circuito Monteblanco. Normally, this sort of behavior is wantonly abusive. But thanks to Porsche’s new active suspension, the car makes the harshest abuses feel like hiccups. It’s a massive engineering achievement in service of pure silliness.
Porsche Active Ride is not the first or only active suspension system out there, but it is arguably the most powerful, and its implementation is fascinating. And note that this is not an adaptive system, which can make damper adjustments electronically, but is only ever reactive; an active suspension system puts force into the body to counteract its motion.
Each corner of the car has a motor-pump unit that controls the amount of hydraulic pressure in the damper with an electric motor. The front and rear motor-pump units are mounted together and share an aluminum housing that bolts up where the traditional anti-roll bar would go, but each wheel moves independently of one another.
For example, the right front wheel hitting a bump doesn’t directly affect the left front. The motor-pump units are powered by the 400-volt battery used in Panamera E-Hybrid models and can put 2,248 pounds of force into each corner of the car. (Porsche Active Ride is also coming to the facelifted Taycan, and the system uses a DC-DC converter to step down from 800 to 400 volts.)
In the Panamera, the Active Ride system pairs with single-chamber air springs, though those are only used to hold the body up. Theoretically, the active dampers alone could take the place of springs, but this would be too energy-intensive, and when turned off, the car would belly down to earth like an old Citroën.
Still, spring rates for the air springs are extremely low for a vehicle of this weight, with such low ground clearance and high cornering capability, around 120 pounds/inch. It’s a little hard to find a good number that puts that into context, but the Ohlins Road & Track coilover kit for the 718 Cayman uses 400 pound/inch springs up front and 456 pounds/inch springs in the back.
It’s not too difficult to understand how the hardware works, but the actual application of the system—what it can do—is genuinely mind-blowing. What’s funny is that Kern wasn’t convinced at first.
“You can basically fake physics, and this is the thing that confused me at the beginning,” Kern says. “It was rudimental at the beginning, so that’s why it felt wrong to me, there was no... I couldn’t feed my sensors.”
Porsche uses Active Ride to eliminate body motions. There’s no roll, pitch, or dive whatsoever. That behavior is useful for maximizing grip and stability, and bad at transmitting feel to the driver, at least initially.
Enthusiasts talk a lot about steering feel, but drivers use more than their hands to suss out what a car is doing. Body motions provide useful information to the eyes, into the inner ear, and through the seat of the pants. Porsche Active Ride doesn’t compensate for tire deflection—what happens when you put load into a tire—so there is some motion, but not a lot.
Those air springs also transmit force into the tires and the body, which is bad where total comfort is concerned, but important for feel. Kern says it felt like “shit” at first. He had no sense of what the car was doing beneath him, so it was impossible to sense the limits of grip. At first, he encouraged the engineers to let the system allow for some body motions, and even half-jokingly suggested using a race-car-style coilover suspension.
David Caredda, one of the masterminds behind the system (and incidentally, a good friend of Kern’s), held firm on the more radical approach of using ultra-soft springs, no anti-roll bars, and dampers to cancel out body motion. The upsides were too tempting.
“The main improvement is that you keep the body as flat as possible,” he says. “You don’t get any inertial forces due to roll movements, pitch movements because these are wheel loads you actually don’t want to have.” These forces reduce grip. “So, keep the car as flat as possible but give [the driver] the response on fine, small excitations.”
An important breakthrough came from using the control software to create what is, effectively, virtual springs.
“The controller has a module which is creating spring forces,” Caredda says.
“It’s virtual,” adds Kern. “It doesn’t exist.”
Wait, what? Caredda and the team didn’t mess with the actual spring; They use the dampers to transmit real force into the car in a way that mimics what a spring does. It was at this point my brain started to split in two.
Porsche uses Active Ride to eliminate body motions. There’s no roll, pitch, or dive whatsoever.
Porsche uses active suspension to essentially mimic conventional suspension systems, but without any of their drawbacks.
“It’s really nice to apply the spring forces just virtually to the car, because you have all the opportunities to use it in the way you need,” Caredda says. “For example, you can apply some roll stiffness to the car when driving straight to be ready for cornering.”
But on the flip side, the car can also reduce roll stiffness quickly if you roll over a curb on the track. So, what one side of the car is doing doesn’t negatively affect the other.
In other words, you can use the system to simulate having no anti-roll bar, or a very stiff bar, then back to no bar in a matter of seconds. This enables, among other things, Kern’s curb-hopping shenanigans. More importantly, you get a spread of ride comfort and dynamic capability that’s pretty much unmatched.
Kern describes Active Ride as being able to generate grip in places where a conventional suspension couldn’t. Porsche calls this “dynamic wheel-load distribution,” and the idea is to use the suspension to spread out force more evenly across all four tires.
In a normal car, turning shifts cornering load to the outside tires as the car’s body rolls away from corner apex. In this instance, the inside tires aren’t doing much. With Active Ride, you can shift load back onto the inside tires, getting all four to help turn the car. So, you get tons more grip and reduce tire wear.
The suspension system operates at 13 hertz, meaning the damper can change its characteristics 13 times a second. To make this possible, an Active Ride car uses accelerometers at the wheels, and an inertial-measurement unit to monitor pitch, roll, yaw, left-to-right, forward-and-back, and up-and-down body motions.
The car’s computers also calculate tire slip angles. Essentially, there’s a virtual model of the car running within the actual car. With all this information, the Active Ride system works in concert with the car’s other systems, including engine, traction motor, all-wheel drive, traction/stability control, ABS, and the electronic locking rear differential.
In Sport and Sport+ modes, Active Ride lowers the Panamera’s ride height for even better handling. The active suspension system also talks with all the car’s other systems, including the engine, traction motor, all-wheel drive, traction/stability control, ABS, and the electronic locking rear differential.
Out on track, the control and finesse Active Ride offers feels remarkable. Thanks to the work of Carreda, Kern, and the rest of Porsche’s engineers, it feels natural quickly. You know that the car is doing freaky things, but what you feel is just uncanny competence. As a driver, you—and more importantly, your inner ear—aren’t left wanting. Active Ride doesn’t make grip limitless because, obviously, that’s impossible, and once you’re past the limit, you get the understeer you’d expect from a 5,200-pound car.
Up until the point of no return, Active Ride flatters the driver too. It works so quickly that it’s almost like the system is preloading the tire for the next driving condition. In each phase of a corner, from braking to exit, you can feel the car smooth everything out, almost regardless of the driver’s inputs.
Monteblanco has a very fast right-hand kink with a curb on the inside of it. With each successive lap, Kern hit the curb a little harder, and every time the car dealt with it like it wasn’t there. You could feel a jolt, but the car was unaffected.
He offered a more extreme example of the suspension's abilities in conversation: The Pflanzgarten section of the Nürburgring Nordschleife is a downhill jump in most cars if you’re really hoofing it. In an active-suspension Porsche, the wheels stay on the ground. (You can see this at 5:37 in the video above.)
Perhaps the most remarkable thing about Porsche’s system is that this is only the beginning. Kern imagines a lightweight sports car with active suspension. It’s a complicated piece of tech, but one that undoubtedly brings huge improvements in grip and comfort. It also has huge implications for road cars with lots of aerodynamic downforce. Typically, you have to run stiff springs to deal with the force acting on an aero car at speed. With Active Ride, you could use dampers to hold the body up on track, while employing soft springs that’ll give good ride quality at slower road speeds. It’s a big change of heart from the driver.
“It was kind of strange because I hated it at first, but I really love it now,” Kern says.
