2011 Porsche 918 Spyder Hybrid Concept

Officially it’s only a concept, but there’s no doubt that project XG10 — or the 918 Spyder concept — will pave the way for the next Porsche supercar. And what a supercar it is going to be: in addition to the normally aspirated, high-revving, 3.4-liter V-8 good for more than 495 hp, the striking 918 Spyder has three electric motors onboard that add another 215 hp to the tally. Says Wolfgang Dürheimer, board member in charge of R&D: “This car can lap the Nürburgring faster than the Carrera GT. At the same time, it averages 78 mpg [on the EU driving cycle] when driven gently. Are we going to build it? We will definitely bring some blank sales contracts to the Geneva show, but it’s too early to talk pricing, production volumes, and timing.

“The strategic aim is to demonstrate that even a supercar can be environmentally friendly. XG10 promises total driving pleasure—and a clear conscience. This is a trendsetting and sustainable premium product that uses the issue of social acceptability to its advantage. And it reflects the legacy of Ferry Porsche, who was convinced that sports cars would never go out of fashion.”

XG10 stands for X1, Geneva 2010. X1 is the code name of the 918 Spyder, which is only one version of many. Potential variations include a 918 coupe, an electric 918, and a 918 RS/RSR. This car can be either two- or four-wheel drive, have plug-in electric or gasoline power, come with an open top or a fixed roof, and be either a racer or a street machine. Its genetic evolution dates back to the 1997 Porsche GT1, which was a Le Mans–winning 911 on steroids. That car triggered project LMP 2000 (Porsche’s exciting Le Mans comeback car), which was halted at the eleventh hour by then-chairman Wendelin Wiedeking, who was always more of a numbers man than a car guy.

Thankfully, Wiedeking and his controller, Holger Härter, allowed Dürheimer to pick up the LMP pieces and convert them into the street-legal Carrera GT, which was launched in 2003 and found 1250 takers. In 2006, Porsche moved on to form the basis of the successful RS Spyder. Four years later, we’re witnessing the debut of XG10, which still uses several Carrera GT elements, such as the front suspension and the forward structure. For 2011, insiders are already predicting LMP1, a race version of the 918 Spyder, which would comply with planned hybrid-friendly Le Mans regulations.

“In terms of performance, XG10 will even eclipse the Carrera GT,” promises a beaming Dürheimer. “In terms of fuel consumption, it beats every microcar. It really does combine the best of both worlds. Thanks to the modularity of the engineering concept, hybridization can quickly filter down to the 911 and the Boxster, if required. Better still, all the R&D work was done in-house—and that includes the performance electronics and the electric motors. There was not a single systems supplier involved in the gestation process. As a result, we own all the intellectual property rights.”

The team of fifty specialists was led by Gernot Döllner, a seasoned and multitalented vehicle engineer. We asked him to name the three most critical crossroads of the concept-defining process. “XG10 started off as a conventional hybrid but then switched to the more practical and more advanced plug-in concept. The number of electric motors and where to position them was also an issue. In the end, we decided to integrate the rear motor in the housing of the seven-speed dual-clutch PDK transmission. We are still experimenting with the packaging of the cooling system. The best solution may be a nose-mounted, low-temperature circuit complemented by a pair of mid-mounted, high-temperature radiators. The body style is not yet cast in stone. Although the show car is a Spyder, generating a coupe version would be simple.”

The design of the low-noise, low-emissions crowd-stopper is the work of Hakan Saracoglu, who works for department chief Michael Mauer. Inspired by such legendary Porsche racing cars as the 908 Spyder and the 917 Le Mans coupe, as well as by the current ALMS RS Spyder, the former Mercedes-Benz and Saab designer masterminded the creation of an emphatically modern sports car with a few familiar touches.

“In a way, the 918 is two cars in one,” explains the soft-spoken design director. “Its character can change from mild to wild and vice versa—mild as in wafting along in eco mode, wild as in switching the drive program selector to sport or race. In mild, the car benefits from the relatively low weight and strong aerodynamic performance. In wild, it improves downforce and stability by extending the adjustable wing, and it raises the two ram-air intake scoops to further enhance thermodynamic efficiency. Design-wise, it was our mission to visualize a brand-new, unique, and revolutionary vehicle concept. Big wheels were a must, the stance had to be positively ground-hugging, and an unmistakable front end was imperative, as was a pacesetting mix of classic curvatures and contemporary creases. There is no doubt that the XG10 marks an important evolution of our design language, certain elements of which are bound to appear on future production models.”

With its redline at 9200 rpm, the normally aspirated 3.4-liter V8 develops at least 495 hp, more than in the RS Spyder but less than the V-10 fitted to the Carrera GT. Although the 918 Spyder weighs 3285 pounds and thus 240 pounds more than its predecessor, the quoted 0-to-62-mph acceleration time of 3.2 seconds beats the previous supercar by 0.7 second.

Porsche’s computer simulations have the XG10 lapping the Nürburgring in 7 minutes, 30 seconds — again beating that 605-hp legend, if only by two seconds.

“That’s what four-wheel drive does for you,” quips Gernot Döllner. “As far as top speed goes, we’re quoting 199 mph. The car could in fact go quite a bit faster, but to do so it would require more downforce, which in turn means more drag. Such a move would not be in-line with the underlying green message.” While the Carrera GT had a drag coefficient of 0.39, the 918 is expected to check out of the wind tunnel at 0.34.

In parallel-hybrid rear-wheel-drive mode, the superclever Porsche can run on gasoline, on electricity, or on a combination thereof. The front wheels, though, are driven on demand by the so-called electric portal axle. The four-wheel torque-vectoring system is tuned for optimum traction, stability, and handling. If required, the mighty V-8 can even act as a supersize range extender — by driving the rear electric motor, which in turn supplies the lithium-ion batteries. In E-mode and with the batteries fully charged, a feather-footed driver can achieve a zero-emissions range of up to sixteen miles. The plug-in charge time varies from two to seven hours, depending on the available voltage. The green-colored brake calipers advertise the energy-regeneration system, which feeds the battery pack behind the seats. The energy cells are also charged when the vehicle is coasting.

A selector attached to the steering wheel chooses among the five different drivetrain operating modes. Electric mode, which drives the front wheels only, is ideally suited for the brief commute between home and freeway. To avoid running out of juice, the so-called driving-range manager will always keep an eye on the nearest charge point, which lights up on the navigation screen. H as in hybrid is the mode of choice in dense urban traffic or in areas where speed limits apply. S stands for sport-hybrid. This is an expressively dynamic setup that prioritizes four-wheel drive with a rear-wheel bias. R denotes race-hybrid and should be used only on circuits where vehicle dynamics are automatically calibrated for the sharpest responses and the most focused performance. Last but not least, the red E-boost button adds a few seconds of unspecified extra oomph for that überaggressive passing maneuver

“It’s this on-demand change of attitude that shows quite clearly that it would be wrong to describe the 918 Spyder as an evolution of the Carrera GT,” states Dürheimer. “After all, this is a highly sophisticated sports car that employs various groundbreaking energy-saving tools to address the dramatically changing driving conditions in which it will operate.”

The control-arm suspension systems and adjustable pushrod-activated spring and damper units underline the car’s track-related heritage, as well as its motorsports ambitions. The same applies to the ceramic composite brakes and to center-lock cast aluminum wheels shod with 255/30YR-21 tires in the front and 295/25YR-22 footwear in the back. Molded-plastic wheel covers were added to smooth the lateral airflow.

Sitting on a 104.3-inch wheelbase, the 918 Spyder is 177 inches long, 76 inches wide and 43 inches low. The cargo bay in the nose cone is said to be big enough to accommodate a couple of soft bags. The fuel tank, which is positioned close to the battery pack, holds 18.5 gallons. The XG10’s core consists of a molded-carbon-fiber monocoque supporting the powertrain, chassis systems, and auxiliary equipment. This light, stiff structure is clad with carbon fiber, aluminum, and magnesium body materials. If the build run was limited to only fifty units, these monocoques could be hand-baked in-house. But since rumors are suggesting more like 750 to 1250 units in total, the 918 Spyder may turn into an object lesson on industrialized carbon-fiber assembly, a task on which Porsche is expected to embark together with Audi and Lamborghini.

Carbon fiber is also the material of choice inside the new super-Porsche. Key cockpit cues include a ramplike center stack (a blend of Carrera GT and Panamera design elements) with turn-knob and touch-pad controls; three large, round instruments; a full-size, center-mounted, seven-inch in-dash monitor; a new three-spoke multifunction steering wheel (it’s round — hurrah!); and two slim bucket seats with integrated safety belts

Three tiny cameras, dubbed Surround Back View, have replaced conventional rearview mirrors. To the left of the steering column, where the ignition key used to live, we now find a start button. To the right is a very simple small gear selector marked PRD. When the drive mode is E or H, the cabin lights up in a slightly eerie acid green. When you select S or R, the visuals changes to fire red. At a glance, the round instruments look familiar, but on closer inspection they actually display plenty of additional information, which can be accessed via two thumbwheels in the steering-wheel spokes.

Among them are active cruise control, pit-lane speed assist, section-control rally assist, braking-regeneration rate, traffic-sign recognition, fuel-content and battery-charge readout, shift indicator, sport chrono function, g-force display, and E-boost reserve. The Powermeter integrated in the rev counter shows all relevant drivetrain-related data such as the actual versus the available performance of the electric motors, energy flow, and current drive mode. Last but not least is the large black touchpad in the center console. It contains the rotary temperature and audio controls as well as buttons to adjust the spring and damper calibration, the position of the wing, and the stability control setup.

“There has never been a car like this before,” maintains the proud project leader. “The 918 Spyder incorporates the best ideas from the top drawers of our most capable engineers.” Mauer agrees: “We pushed the envelope as far as exterior and interior design is concerned. This car shouts Porsche from every angle, and yet it is truly advanced and not at all retro. We tried quite a few new things, like the rather extreme proportions between body and the wheels, the innovative airflow management along the rear side panels, the evolutionary head- and taillamp treatment, and the active aerodynamics.

“Inside, the goal was to rewrite the rulebook of ergonomics. That’s why all major controls are either on or very close to the steering wheel. The instruments are easy to read, the layout of the center console is as intuitive as they come, and there is a distinct quality feel to every detail of the cockpit.”

Despite the tighter overall dimensions, the cabin packaging is actually more generous than in the Carrera GT

When times were good and Porsche was still cash-rich, Messieurs Wiedeking and Härter could have easily signed off X1 as the brand’s next halo car. But they left it to the next top management, under Michael Macht and Dürheimer, to give the 918 Spyder the go-ahead. Surely the new leaders doubled-checked with Wolfsburg whether this was an OK project, surely they consulted with Ferdinand Piëch before selecting the 918 model designation? No comment.

But the R&D chief is quick to point out that Porsche did evaluate the full range of existing and potentially promising propulsion concepts before zooming in on the high-performance plug-in hybrid. The next major task is to ensure feasibility and thus profitability.

“There is no doubt that the 918 Spyder will have to cost more than the Carrera GT,” acknowledges Dürheimer, easing into the subject. “How much more? It depends on the volume. If we settled for the aforementioned fifty units, we could build the engines in Weissach, get away with only three prototypes, and assemble the customer cars practically by hand.” But you can tell that this is not the favored game plan. You can sense that bettering the previous supercar is what the next supercar should be all about.

“Let me put it this way: if customer feedback is positive and we end up over time with about 1000 firm orders, I would be very pleased.”

Source: Automobilemag