2016-09-06
The Key Technologies Inside the...
Information: http://www.automobilemag.com/news/key-technologies-inside-2017-porsche-panamera-turbo/
The Key Technologies Inside the 2017 Porsche Panamera Turbo
We are entering an age of rapid automotive innovation. For instance, the electronic systems in the Ferrari 488 GTB can practically hold a drift for you, and the brain in the Tesla Model S will even drive for you, though we don’t recommend it. Porsche, meanwhile, is an automotive manufacturer that always impresses with its technological achievements. From its outstandingly fast PDK dual-clutch transmissions to the extremely clever powertrain in the 918 Spyder, Stuttgart’s developmental focus is clearly on sporting prowess. To see what new technologies Porsche has been working on, the company invited us to Germany to take a look at the 2017 Panamera Turbo. Here are the key technologies we think enthusiasts should be aware of.
Aerodynamics
One of the new Panamera’s standout features is the three-piece extending spoiler affixed to the rear of the car. Looking elegant as it raises from the recess in the trunk lid, it offers function as well as form. The rear spoiler has three set points positioned according to driving conditions. At low speeds the spoiler is unnecessary and stays in its recess. At cruising speeds of up to 125 mph the spoiler deploys in true transformer fashion, reducing drag at the rear of the car. This might sound counterintuitive to the aerodynamically inclined, however the economy position helps with flow separation at the rear of the body and, more importantly, it moves an area of high pressure away from the rear window. At speeds of 125 mph and above, the wing’s angle of attack is increased to provide optimum downforce on the rear axle. The spoiler in its most aggressive state provides a lift coefficient of -0.01, which equates to an additional 440 pounds pushing down on the rear of the car at 186 mph.
Another innovation by Porsche is to completely box off the inlet and exhaust sections in the engine bay. From the moment air enters through the front grille, it is channeled to where it is needed. Adaptive slats in the front grille can open or close—or anything in between—to meter the airflow into the engine bay. This can either reduce drag (when closed) or increase cooling (when opened). The exhaust piping is also boxed off under a thermal blanket all the way down past the bulkhead. This allows air to pass around the exhaust pipe and take away heat before exiting the car’s flat underside.
Functional front fender vents release high-pressure buildup around the wheels, which should rid the car of nervous hopping or bouncing at speed. They also offer an escape for any heat buildup from the optional 10-piston carbon brakes, reducing the risk of fade under sustained abuse.
Chassis
Porsche was keen to get across its latest technology, termed 4D Chassis Control. With a varied list of performance-orientated chassis systems available, 4D Chassis Control ties them all together. Some of the performance systems include:
Porsche Torque Vectoring Plus is a rear differential that contains clutch packs that disseminate torque to either wheel, depending on the driving conditions. For example, to help the car corner better, the outside wheel is provided with more torque than the inner. This creates a moment of yaw that points the nose of the car in tighter than when not used. What is yaw, I hear you ask? Yaw is a term for the rotation of the car around a center point. Imagine a large metal spike driven through the roof and to the ground, dead in the middle of the car. The car spinning around this spike is yaw. The brakes can also be modulated to drag one side of the car, again inducing a moment of yaw on the vehicle.
Porsche Active Suspension Management joins the magnetic-damper and air-spring systems together to control the Panamera Turbo’s suspension. Magnetorheological dampers allow the bump and rebound rate of each shock absorber to be adjusted independently, based upon driving style and road conditions. The adaptive air suspension has three chambers that allow for three spring rates depending on drive mode selected. A raised mode increases ride height by 0.8 inch, whereas a lowered mode — 1.1 inches lower at the front and 0.8 inch at the rear — makes use of the flat undertray for useful ground-effect downforce. The three drive modes chosen by the turn of the steering-wheel-mounted switch are Normal, Sport, and Sport Plus.
Porsche Dynamic Chassis Control Sport electromechanically adjusts the anti-roll bars for stiffness. A centrally mounted unit twists at a higher speed than the previously used hydraulic units to adjust the roll stiffness at each axle.
The 4D Chassis Control system looks at inputs from the driver and the attitude of the car and then modifies the chassis systems to give the Panamera the best setup to negotiate a turn at the highest possible speed.
This isn’t just a simple program that talks to all of the sub-systems. The previous model Panamera had around 2 million lines of code that dealt with electronic systems, but the new model has more than 100 million lines of code.
Powertrain
Porsche designed three new engines for the Panamera model range: a 4.0-liter V-8, a 2.9-liter V-6, and a 4.0-liter V-8 diesel. The most powerful engine finds its home in the Panamera Turbo and achieves peak power of 550 hp between 5,750 and 6,000 rpm. Two turbochargers are placed in the “hot V,” splayed at an angle of 90 degrees. The positioning of the turbos is important not only for the small packaging of the engine but also to reduce the length of inlet and exhaust manifold piping, which in turn reduces turbo lag. The larger V-8 engine benefits from cylinder deactivation by using a sliding cam system, which can improve fuel economy by up to 30 percent. At engine loads less than 185 lb-ft of torque, half of the cylinder’s valves close fully and form an air spring to minimize losses.
What is noticeable from the Panamera Turbo’s power curve is that the V-8 might not be performing quite to its full potential. The specific power of the V-6 is quoted at 152 hp/liter, whereas the V-8 — which is practically the same engine but with two more cylinders — only achieves 137.5 hp/liter. The reason for this disparity in efficiency is the fact that the V-8 is currently only running 1.4 bar of boost, whereas the V-6 runs 2.0 bar, which is the limit of the engine family. We pushed the manager of powertrains, Markus Sitzler, on this, and he let slip that the V-8 is capable of taking the same boost pressure as the V-6, and it may be held back for the future addition of an S or GTS model to the Panamera range. Extrapolating the numbers forward, we can assume that when the V-8 is on full boost it will produce power in the region of 608 hp.
Verdict
How does this all feel? Although we weren’t afforded the opportunity to drive the Panamera Turbo ourselves, we were treated to a hot lap with a steering systems engineer. In Sport Plus mode the Panamera controls its weight well, carving into the asphalt while the plethora of systems pulls the car around the corner. With 568 lb-ft of torque available from the V-8, power oversteer on corner exit is not only possible but enjoyable and easy to catch. Understeer does rear its ugly head when pushing hard, however this is expected with an AWD system and an engine over the front axle.
Overall, the new Panamera Turbo is an exciting proposition. With more technology than you can shake a stick at and performance that astounds, we can’t wait to drive it ourselves.