Porsche 918 Spyder First Ride by Motor Trend...
(19 March 2012)
"I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth." John F. Kennedy was sticking his neck out a long way in May 1961. It was still some nine months before John Glenn had even orbited the earth. There's that sort of bold aspiration in Porsche's announcement that production of the first of the 918 examples of the 918 Spyder will begin on 9/18/2013. They said that before they'd ever had a prototype running. And this is no ordinarily predictable project. It's the most technically ambitious sports car ever.
It's a hyper-performance two-seater with an all-wheel-drive plug-in hybrid drivetrain. It shares barely a single component with any other vehicle. But if you think that gives grounds for uncertainty, you just don't think like a Porsche engineer thinks. The company decided to build a concept-car only in September 2009; it was unveiled at Geneva in March 2010. But that really was just a show-pony, not an engineered package. Feasibility studies were undertaken that summer, so the production green light occurred a scant three years before job one. In an industry where it usually takes two years just to perform a mid-cycle facelift, the 918 Spyder represents engineering at lightning speed.
Yet here I am at the Nardo high-speed test track in southern Italy standing by the 918 Spyder test car, and precision engineering might not be the first phrase to come to mind. It's mostly un-bodied, and even where there are panels they have several-inch gaps between them. Everywhere you look it's duct tape, cable ties, crooked screw heads and unintelligible German scribbles. Exposed pipes and wires untidily snake all over the place. The cockpit is near uninhabitable; you share it with any number of temporary controls, data acquisition equipment and a noodle-salad of cabling.
Don't be deceived. This is the very first rolling chassis. It's only seven weeks old when I ride in it. That's in itself an astounding fact: a major manufacturer letting an outsider experience a car so early in its development journey. This vehicle contains all the major production-intent systems. These systems are bewilderingly exotic in themselves, but they don't just need to work as standalone pieces. Obviously they will need to integrate with each other under the command of 55 electronic controllers. The prime mover is a bespoke 4.6-liter V-8, with flat-plane crank and titanium connecting rods. It's derived in principle from the V-8 in the RS Spyder ALMS racer, but no parts are shared. It revs to 9000 rpm, an astonishing figure in isolation but even more so when you consider it has direct injection. The engine weighs just 290 pounds, a scant 25 pounds more than the race engine, even though it's rated to pass all Porsche's road-car durability tests. It makes 570 horsepower -- wildly impressive for just 4.6-liters, and a better power-to-displacement number than the 5.7-liter V-10 found in the 604 hp Carrera GT. Still though, Porsche's old super-duper car made more power, right? Not quite.
We haven't yet talked about the 918 Spyder's the two electric motors. The one at the back, between engine and transmission, makes 90kW (121 hp), and the one for the font wheels is 80kW (107 hp). These numbers are provisional; they might rise some more. Porsche R&D chief Wolfgang Hatz isn't shy of talking about a final total system power north of 800 horsepower.
The rear powertrain consists of the V-8, and behind it a decoupling clutch, then the e-motor, then a seven-speed PDK twin-clutch transmission. The decoupler aft of the V-8 means it can be shut down permanently for the driver-selectable electric-only mode, and temporarily for the hybrid mode. So the rear electric-motor drives through the seven-speed box and can operate at all road speeds up to the 202mph top-end. The front motor runs a single reduction ratio and is decoupled at 146mph to avoid over-revving. In pure-electric-mode, the 918 Spyder can pull 0-60s in about 9 seconds, and thanks to its 6.8kWh battery capacity should go about 15 miles if you drive like the man from the EPA.
But you don't drive like that, do you? So for you there will be a little rotary knob on the steering wheel. Turn it out of e-mode, through hybrid mode and into sport mode. Now the V-8 is permanently clutched in, which should do away with worries about system lag when you mash the gas. It also means permanent exposure to its ear-tingling cadenzas: the exhaust system is packaged inside and above the V, and the two pipes fire obliquely backwards like anti-aircraft guns, from a position just less than two feet behind your ears. Where you see them on this mule is where they will be in real life. In this position, their heat is easily vented, rather than soaking into the engine bay and towards the battery.
Another twist of the dial and you're in race mode. All systems are set to maximum, and the battery will cycle deeper. In two-second bursts the electric motors alone will make 260 hp -- the same total amount as a 1974 911 Turbo. And the output power of the electrical systems means they have huge input power too: the system can generate 0.5g worth of deceleration via regenerative braking. That means more electrical energy is available next time the car accelerates. Zero to sixty should fall under 3 seconds flat -- in fact Porsche claims 0-100 km/h will be under 3.0, and it always claims conservatively. More fantastically, 0-125 mph should happen in less than nine seconds, and 0-186 mph (300km/h) in under 27. Those are hypercar figures boys and girls.
The car comes to rest beside me, and I'm invited to the passenger seat. Strangely, the engine is running. I guess, and my engineer-driver confirms, that because they are doing a lot of electric-only acceleration runs today, they're using every chance to keep the battery topped up via the gas engine -- this is a hack mode exactly similar to what Chevy did with the Volt on press outings, and not normal for the production car. So when I'm strapped in, the V-8 cuts out, and we bowl up the straightaway, eventually getting to about 60 mph before he lifts off. Turns out the electrical systems are running at about half power today and 0-60 mph takes longer than the 9 seconds they're claiming for full electric. Also, with no gas beng consumed, the e-mode 918 should do 90+ mph "flat out". In gentle electric acceleration from rest, it's the front motor that does the driving, because the single-speed front gearbox has less friction than the 7-speed PDK at the rear. Yes, a FWD Porsche. At certain times, anyway.
We swing around and return. This time the V-8 kicks in, and hard. The driver pulls the upshift paddle every time it gets to 6000 rpm, by which time it's beginning to sound pretty darned Le Mans. Then instead of going back to the pit, he peels off to the right, down another wide runway, and takes the chance to saw the wheel left and right repeatedly. The lateral forces pull my five-point harness like a heavy bear is running on my chest.
The 918 has to handle properly. Has to: Porsche has given itself a public target 7 minute 22 second Nordschleife time, so to miss it would be (as the kiddies say) an epic fail. To achieve it, there's a 'hot lap' mode that allows the battery to end the lap more depleted than it starts. That's 10 seconds quicker than the Carrera GT. Well, in the workshop where this prototype lives, I also saw a Carrera GT crudely modified to use the suspension geometry, tires and dampers of the 918, and with ballast weights to simulate the new car too. Sad to see this lovely car brutalized, but at least it's for a good reason. I spoke to several chassis engineers and they all admit now (as does Walter Rohrl) that the Carrera GT was evil on the limit. This simulator has a higher but friendlier outer edge. And that's without the front-axle drive that will further stabilize the final, production 918 Spyder.
The dynamics engineers had clear priorities for the packaging guys: low weight, and weight mounted low. That's difficult when there were 700 pounds of hybrid gubbins to include. But they have kept it under 3750 pounds, all-in. The V-8 is dry-sumped and is mounted almost entirely below the center-height of the wheels. The PDK is upside-down from the usual orientation (and so has a bespoke casing as well as almost all-new internal parts versus Porsche's other units), and the battery is behind the occupants' buttocks. Increased efficiency allows the fuel tank to be 18.5 gallons versus 23.8 in the Carrera GT, and it's mounted low, too.
The electronic stability system will not only be able to call on the front wheels to keep the car pointing where you ask: it also commands rear-wheel steering. That's right, all-wheel steering. It's normally programmed to counter-steer at low speed for agility, and work in phase with the front wheels at speed for stability. Active dampers are standard too, and carbon-ceramic brakes of course.
By a margin of 0.05 of an inch over the Cayenne, the 918 Spyder is the widest car Porsche makes, at 76.4 in, with a length of 182.8 in. It's by far Porsche's lowest, at 45.9 in -- the driver sits even lower than in the Carrera GT. That helps it roll so very little and grip so hard. The space taken up by the hybrid equipment means the 918 doesn't have space for Carrera GT-type inboard pushrod-operated springs and dampers, and anyway they were deemed too heavy. The next phase of prototypes, which were being built while I rode in the rolling chassis, will have the production car's active aerodynamics. The system comprises a four-position rear wing, an active front diffuser, an active underfloor flap, and an active radiator flap. Acting under central control, these allow drag, downforce and cooling to be tuned as needed, in real time.
It will be a habitable car, not too stripped of comfort. The twin carbon fiber roof panels will fit in the front trunk. There will be an 11-speaker sound system. All the instruments will be part of a reconfigurable TFT screen. A new touch-screen navigation/entertainment/connectivity system is being designed for the center console. Air conditioning will be standard, and an electric cabin heater an option. So will be a nose lifter for steep car park ramps. Porsche knows its buyers: another option is to be a 'track pack' of lighter wheels (magnesium: minus 26 pounds) and even lower, stiffer suspension, plus further weight-cutting measures. A high proportion of the buyers are likely to use the car on-track, the engineers all say.
Ah, the buyers. I can't with much ease climb inside the minds of people who drop a million bucks on a supercar. Well, 768,000 Euros at any rate. But I voiced my guess what some of those potential richies would holler: chuck away the hybrid nonsense and give us an ultra-light racetrack murdering double hyper car. It turns out that about half do indeed say that, at least when they first express an interest in the car. But the sales technique is simple. They're just strapped into the passenger seat of one of Porsche's experimental four-wheel-drive electric Boxsters, and the accelerator is floored. Apparently they soon come to see the appeal of a powerful electric motor or two. Whether they want the highest-tech supercar around, the highest-efficiency or simply the highest-performance, the 918 Spyder is on course to have all the bases covered.
Porsche 918 Spyder Prototype Right Side
Porsche 918 Spyder Prototype Front
Porsche 918 Spyder Prototype Front Three Quarter
Porsche 918 Spyder Prototype Right Side Door Open
Porsche 918 Spyder Prototype Front Three Quarter On Track
Porsche 918 Spyder Prototype Passenger Cell
Porsche 918 Spyder Prototype Seat Molds
Porsche 918 Spyder Prototype Engine
Porsche 918 Spyder Prototype Left Side
Porsche 918 Spyder Prototype Front On Track
Porsche 918 Spyder Prototype
Porsche 918 Spyder Prototype Electric Motor
Porsche 918 Spyder Prototype Head
Porsche 918 Spyder Prototype Connecting Rod
Porsche 918 Spyder Prototype Engine Block
Porsche 918 Spyder Prototype Camshaft
Porsche 918 Spyder Prototype Crankshaft
But how does this camshaft work?
