Porsche 918 Spyder

	Porsche 918 Spyder
	Debut: 2013 Maker: Porsche Predecessor: Carrera GT

Published on 9 Mar 2014

In the nearly 50 years history of supercars, there were a few milestones. Lamborghini Miura was the one that started all and defined what supercars should be: exotic design, incredibly low body, mid-mounted and extremely powerful engine. The first generation supercars including Countach and Ferrari Berlinetta Boxer were actually very difficult to drive and to live with. Porsche 959 changed this impression with computer-controlled 4-wheel-drive, adjustable suspension, a roomy cabin and manageable controls. Meanwhile, Ferrari F40 brought race-car-sharp handling and a true 200 mph top speed for the first time.

McLaren F1 was another milestone that everybody should remember. Not only its jaw-dropping 240 mph top speed or incredible acceleration figures, it was renowned for lightweight, central driving position, active aero and a marvelous naturally aspirated V12. Although the F1's speed records would be unparalleled in the next 12 years, its handling could not match the 4WD Bugatti EB110, another milestone in my opinion. However, it was another Bugatti that rewrote history again. EB16.4 Veyron was not just about spectacular performance and mechanical specifications (something like a 16-cylinder engine in W formation, 4 turbos, twin-clutch gearbox and 4WD), it was its easy handling and controls that made it special among supercars.

But the domination of Veyron lasted only 8 years. By 2013, the supercar world became tired of Bugatti's supersize approach and called for smart performance. Like what Formula One racing has been pursuing, KERS (kinetic energy recovery system) or hybrid technology takes the limelight. 3 such supercars were announced in the same year: Porsche 918 Spyder, McLaren P1 and Ferrari LaFerrari. Conceived the earliest, Porsche 918 Spyder reached production just ahead of its rivals and became the first ever hybrid supercar. In other words, a new milestone is laid.

Styling and Aerodynamics

Unexpectedly, the first hybrid supercar looks a bit retro. Its proportion looks close to those of Porsche 907, 908 or 917, the 1960s and 70s endurance race cars, as this is evident in the especially curvy fenders, wraparound windscreen and large headlamps. Like its predecessor Carrera GT, a targa roof is chosen to enhance its showroom appeal. The windscreen might be a bit more upright than desired, but this conforms to the tradition of Weissach – styling should not compromise functions.

Behind the cockpit is a pair of rollover hoops fully integrated with the carbon-fiber body shell. Further down there is a pair of top mounted exhaust. Yes, this car has its exhaust gas emitted right above the engine compartment like factory chimneys. This enables the shortest possible path and reduces back pressure. Moreover, it moves the hot exhaust system further away from the floor-mounted battery pack, allowing the latter to work at its optimum operating temperature of 20-40 deg C.

Design of the back end is more interesting than the front. Underneath the 3-stage adjustable rear wing there is a pair of stylish taillights, large hot air vents and a diffuser. As you would expect, the 918 Spyder features active aero, including the aforementioned rear wing, a pair of movable aero flaps at the front underbody and active front intake shutters. Nevertheless, its aerodynamics performance is probably not as good as McLaren or Ferrari. Drag coefficient is 0.36 for the standard car or 0.35 with Weissach package option (which adds aero blades at the rear end and aero flaps in the front air outlets), while down force numbers are not even revealed.

Chassis, suspension, steering and electrical propulsion system

Under the carbon-fiber body shell is a chassis that looks remarkably close to that of Carrera GT. It employs not only a carbon-fiber tub with integral windscreen and rollover hoops but also a carbon-fiber rear subframe on which the engine and rear suspensions are mounted. The latter contrasts to the aluminum ones on McLaren and Ferrari as well as the chromed moly tubular frames of Pagani and Koenigsegg. The whole carbon-fiber monocoque is produced by Austrian company CarboTech, which also supplies the Monocell of McLaren.

Whether the full carbon-fiber construction delivers significant weight advantage I would not say. In fact, the 918 Spyder is not exactly a lightweight. In standard form it tips the DIN scale at a considerable 1675 kg. Even if you tick the lightweight Weissach package, which includes central-locking magnesium wheels (which save 15 kg), titanium brake components, ceramic wheel bearings, CFRP rear anti-roll bar, plastic film body coating (instead of paint) and has the air-con and audio system deleted, it still weighs some 1634 kg. While that number might sound fabulous beside Bugatti Veyron, it is 144 kg more than McLaren P1 and likely to be 270 kg more than LaFerrari (if Maranello delivers its promise).

Part of the reason is its heavier electrical propulsion system. The Porsche is the only car in the trio to offer a truly usable electric drive mode – it can cover up to 30 km (18.6 miles), at a speed up to 93 mph (150 km/h) and accelerate from 0-60 mph in just under 6 seconds. This necessitates a larger, 6.8 kWh lithium-ion battery and a pair of electric motors with a combined output of 286 horsepower and 431 pound-foot of torque. As a result, the E-power system weighs as much as 314 kg. Another reason is Porsche wants to offer electric 4WD to improve its handling, therefore it decides to employ 2 electric motors – a 129 hp front motor drives the front axle through a fixed gear ratio, while a 156 hp rear motor sits between the engine and gearbox and provides extra power to the rear axle. It goes without saying the 2-motor layout is heavier than the single-motor design of its rivals. To avoid over-rev, the front motor is disengaged above 146 mph, by that speed on highway I suppose you no longer need the extra traction.

The large battery pack is placed on the floor just behind the seats and protected by the carbon-fiber tub. This guarantees a low center of gravity. Meanwhile, the front motor helps improving front-to-rear weight distribution to 43:57, slightly better than Carrera GT. The fuel tank sits right above the battery.

The double-wishbone front suspensions and multi-link rear suspensions are attached to the monocoque through racing-style uniball joints. They incorporate adaptive dampers which is part of PASM. Note that the 918 abandons the Carrera GT's pushrod-operated inboard spring/damper units for a conventional outboard and vertical design because the PASM dampers are taken from the production parts pool.

As expected, the steering rack employs electrical assistance by ZF. Like 911 GT3 and Turbo, it also employs 4-wheel steering – actually the system was first developed on the 918 prototype and then transferred to the production cars. At low speed it steers the rear wheels in opposite direction to quicken turn-in and reduce turning radius. At higher speeds the rear wheels turn in the same direction to enhance stability.

Braking is provided by PCCB carbon-ceramic brakes. The front employs 410 mm discs and 6-piston calipers while the rear uses 390 mm discs and 4-pot calipers. Other goodies include an electronic-controlled rear LSD and brake-based PTV torque vectoring.

Engine, Transmission and Performance

Interestingly, the internal combustion engine is a Ferrari-style naturally aspirated flat-crank V8. It displaces only 4.6 liters, merely 100 c.c. more than Ferrari 458 thus is unusually small for a top-tier supercar. However, it is even higher revving and more powerful than the 458 engine. Thanks to lightweight flat-plane crankshaft, titanium connecting rods and other technologies learnt from the RS Spyder racing program, it is capable to rev to 9150 rpm and produce 608 horsepower at 8700 rpm. Maximum torque is 398 pound-foot at 6700 rpm. Yes, the torque delivery is quite peaky, but the electric motors compensate the lack of urge at low rev thus this is never a problem. In fact, from merely 800 to 5000 rpm it offers at least 590 lbft of torque for your disposal! Total system output is 887 hp and 944 lbft, the former is slightly less than McLaren P1 and LaFerrari but the latter trumps both easily.

To make possible the top exhaust, this V8 employs inverse breathing, i.e. the exhaust is located inside the V and the intakes are on the outside. Its thin-wall exhaust system is made of Inconel, a nickel-based alloy that is both lightweight and heat resisting. The induction manifolds and air box are made of carbon-fiber reinforced plastic. As expected, dry-sump lubrication is chosen to mount the engine as close to the ground as possible. In fact, the mounting is so low that the 7-speed PDK gearbox has to be turned upside down to align with the crankshaft.

As for performance, Porsche claims the 918 Spyder has a top speed of 214 mph. It lacks both the horsepower and low-drag aerodynamics to challenge Bugatti or Koenigsegg in this respect. Acceleration is much better. With the help of front and rear E-motors, it can have 0-60 mph accomplished in only 2.5 seconds. Nevertheless, it still can't quite match Bugatti Veyron SS in the process to reach 200 km/h (7.2 sec versus 6.7 sec) and 300 km/h (19.9 sec versus 14.6 sec). Both McLaren P1 and LaFerrari will have it beaten in these measurements, too.

However, as we all know, Porsche is never interested in breaking straight-line speed records. Instead, it pursues to offer the highest real-world performance, which is best measured by lap time in Nurburgring Nordschleife. The 918 set a new lap record there at 6 minutes 57 seconds, being the first production car to break the 7 minutes barrier (note: we deliberately ignore the Radical SR8 for obvious reasons). Rumors said McLaren P1 could be even faster, but so far there is no official confirmation, so the 918 remains to be the King of the Ring.

On the Road

Interestingly, the Porsche supercar starts with electric mode and slips into the street with complete silence, very much like a Toyota Prius. Press the throttle harder and the V8 fires into life. The transition is smooth but you are instantly aware of the engine from its noise and some vibrations. The V8 is very responsive to throttle, and this sensation is further amplified by the instant torque of electric motors. The engine itself delivers the power linearly. Rev beyond 4500 rpm and it starts getting serious. You can't help flicking the driving mode from Hybrid to Sport and then Race, speeding up the throttle and PDK gearshift in the process. From 7000 to 9150 rpm the engine screams like a racing motor. Its sound is so much more beautiful than that of McLaren P1, being creamier and more addictive. Thankfully, Porsche opted not to use turbocharging.

Is it as quick as claimed? Yes, no doubt. The electric motors pull it out of corner with such violence that not even Bugatti Veyron seemed to match. In fact, the combination of electric power, e-4WD, 4WS and torque-vectoring makes it feel like 200-300 kg lighter than it actually is, because it accelerates so quickly, turns in so sharply and corners so flatly and neutrally. Thanks to the Michelin Pilot Sport Cup 2 rubbers, you can push it incredibly hard into apex, get back on power incredibly early and utilize the extra front-end traction to take it out of corner. The calibration of all the hybrid system and electronic driving aids is so well done. Even if you switch off the ESP, it won't suffer from big slides like a Carrera GT, a testament of the excellent inherent balance.

Unlike that on the regular 911, the electrical power steering on 918 gets overwhelming praises from motoring journalists. It is quick, well weighted and, most important, feels connected to the road. In contrast, the brake is not so good. Blame to the regenerative braking, the initial travel feels soft and artificial. Press harder and the ceramic brakes are engaged, then the brake feel returns to normal. Rivals McLaren and Ferrari probably know this very well from their F1 experience thus they decided not to use regenerative braking. Perhaps Porsche should not let efficiency to compromise the driving experience. As it is, braking becomes the Achilles' Heel of the otherwise flawless 918.

Like Bugatti, the 918 is easy to live with. Its ride is surprisingly supple for a supercar if you leave it in normal mode. The roof panel can be detached and stored in the front boot. The cabin offers plenty of room and good seats. Visibility to the front is excellent. Not so good at the rear but acceptable for a supercar. The build quality follows the usual standards of Porsche, which should put McLaren P1 in shame. Its exterior body panels are tightly fitted with narrow assembly gaps. The paint is perfectly done. The interior is not only very well built but also very stylish. Highlight must be the floating center console with integrated touchscreen. It is also well equipped, with sat-nav, infotainment system, Bluetooth connection and a classy Hi-Fi system – alright, not standard fitted to the Weissach pack but they are no-cost options. Pagani still builds the classiest cabin, but the Porsche has to be the most modern and usable.

As expected, the 918 Spyder is very expensive. The standard version costs €780,000 (£650,000) while Weissach pack commands €850,000 (£710,000). Porsche wants to build a total of 918 units, an ambitious number for this very exclusive class, even though Carrera GT managed to find 1270 buyers. Considering the enormous development costs of its sophisticated hybrid system, it might not turn a profit. However, the technologies it pioneered will undoubtedly benefit future generations of 911, just like what 959 did many years ago.

Verdict: