Porsche 918 Spyder – Electrifying the Supercar

by Lawrence Romanosky on April 24, 2014

Porsche 918 Spyder on the trackI finally got a chance to visit Road Atlanta, the iconic track in Georgia and home to IMSA racing, the Petit Le Mans, and the SCCA Runoffs which I have read about in Peter Egan’s column in Road & Track Magazine going back to the 1980’s. Only this time I was going to be driving a 887hp Porsche 918 Spyder, not a Formula Ford or Bugeye Sprite.

To be honest, seeing the unforgiving run offs lined with imposing concrete walls, the grass soaked from a week of rain and a damp track, I was wishing I could learn the track in a 100hp Sprite! Thankfully I had Cass Whitehead, former IMSA driver and one of the few people in the world certified to drive the 918 by the Porsche Factory, to be my in-car instructor. Cass’s instruction along with the full complement of Porsche Factory engineers and trainers cycled a group of about 80 dealership staff from Canada and the US through an ‘Expert’ 918 program which I was lucky enough to attend, and luckier still not to disgrace myself by crashing the car! This high-level 918 education and demonstration of the finished product proved enlightening and answered a lot of questions that I had about the car.

About the 918 Spyder

It is quite a piece of engineering and arguably the most sophisticated passenger car ever developed. Following in the footsteps of the 959 from the late 80’s, the 918 introduces a host of new technology that will be adopted by Porsche’s volume models in the future.

Powertrain

2014 Porsche 918 PowertrainMotive force is provided by a race-derived, 9,150rpm 608hp 4.6L V8, along with electric motors operating on both front and rear axles. The combustion engine is dry sump with a flat plane crank and direct injection with a very high specific output of 132.2 hp/L and very low weight of just 135kg (a 4.8L Cayenne GTS V8 weighs over 200kg and produces 420hp). It also has a unique cylinder head design allowing intake air to enter on the sides, and exit on the top of the engine between the V, opposite of most engines. This provides several advantages, mainly keeping the heat away from the batteries and sensitive electronics and offering the fabulous top-exiting Inconel exhaust. Total system power is 887hp@ 8700rpm with a maximum of 944lb/ft Torque, with more than 590lb/ft from 800-5,000rpm. The engine runs without any ancillary drive belts as the a/c compressor, water pump, power steering etc. are all run from the cars electrical system. The 129hp front electric motor, which is mainly used for purely electric driving and the charging of the battery, runs parallel to the front axle with a fixed reduction ratio and revs to 15,000rpm. It is disengaged at speeds over 265kph to avoid over revving. With close to 900hp, the added traction provided by the AWD ads a huge measure of confidence, especially in the lower gears where 2 wheels simply can not put that much power to the ground.

The 154hp rear electric motor is sandwiched between the combustion engine and the PDK gearbox which is turned upside down to aid airflow underneath the car. The positioning of the motor allows to take advantage of the torque multiplication provided by the gear box. It is also used to start the car, eliminating the need for a separate starter motor.

There is a 135kg, 6.8kw/h, 230kW Li-Ion Battery pack which is fed either though the combustion engine, regenerative braking, or plugged into the power grid. The battery can be charged in about 2 hours with the 220V charging station, or in as little as 7-10 minutes with the combustion engine. The 918 Spyder also has a very highly developed regenerative braking system that is active up to .5g in deceleration, beyond which the hydraulic friction brakes engage. Engineers went to great lengths to capture as much kinetic energy as possible, whist still offering consistent brake feel – a huge challenge. Integrating all of the above are the on board computers and power electronics which manage the distribution of mechanical power and the flow of AC and DC energy. Calibrating all these components was an unbelievable challenge, and a huge success, as the driver is not distracted by the technology, only amazed by the ability of the car.

Driving Modes

There are 4 driving modes that can be selected by turning a rotary controller on the steering wheel. The car will start out in E-Power and run only on electricity, but turning the controller changes the efficiency/performance characteristics of the car to Hybrid, Sport Hybrid and Race Hybrid as well as offering a Hot Lap function for maximum system performance. These settings control not just the intervention of the combustion engine but the Active Aerodynamics as well; opening and closing the front cooling flaps, the front underbody diffuser and the extension and angle of attack of the rear wing. E-Power will get you up to 30km of range driving on just battery power, although pressing through the detent mid way through the throttle pedal travel will awake the combustion engine. The Hybrid mode maximizes the overall efficiency of the vehicle toggling between the electric motors and combustion engine or both as the situation warrants. In Sport-Hybrid and Race-Hybrid the combustion engine is always on, with increasing electrical contributions in the latter. The Hot Lap mode is activated by a red button in the centre of the controller, and gives maximum performance by rapidly depleting the electrical reserves to the electric motors.

2014 Porsche 918 Body and Chassis

Body and Chassis

The 918 Spyder is built like an endurance racing car, with an entirely carbon fiber chassis with non stressed bolt-on external panels – the car can be driven without any of the bodywork which is there only for styling and to manage airflow. Weight was pared wherever possible and virtually all components are unique to the car. The 918 shares a number of technologies from the Porsche 991 Turbo(S) and the GT3, including rear wheel steering which can toe-in or toe-out the rear wheels to effectively change the wheelbase, depending on whether maneuverability or stability is desirable.

Also PTV is in place with a fully variable rear differential lock as well as PASM adjustable dampers. There is also a front axle lift option for the car which we are told is more or less essential and only weighs 6kg. Michelin co-developed a new tire for the car – the Michelin Pilot Cup Sport 2 – which manages to offer higher levels of grip, along with greater longevity compared to the first generation version.

Because of the engine design, where all the exhaust and catalytic converters lie on top of the engine, there is no access to the engine compartment without tools. There is a flap that opens for oil and coolant fill, similar to what we have with ou Porsche 991 and 981 sports cars.

Weissach Package

The Porsche Weissach package offers a host of weight saving measures including magnesium wheels, Ceramic wheel bearings, titanium brake parts, titanium chassis fasteners, a Carbon Fiber rear stabilizer bar and paint delete with foil wrap in racing livery for the exterior panels. Visually, the roof and spoiler are all in bare Carbon Fiber and in the interior, Carbon Fiber dash pieces and door trim are substituted for aluminum. If you omit everything including the Burmester Infotainment system, glove box, door handles etc. you can save 41kg which is worth 3sec per lap at the Nurburgring. The Weissach package adds $84,000 to the $845,000 (USD) price of the car, with the wheels accounting for almost half of the weight saving, and price increase. You can add back any of the deletions without charge.

Interior

2014 Porsche 918 Spyder Interior Driver PerspectiveAll in all it is is very well executed and functional cabin. Storage space wasn’t a top priority with the design but there is a glovebox and some 918 fitted luggage that makes the best use of the space available. This car is about 13cm (5”) lower than a 911, it has wider sills, and a more confined cockpit with less adjustment than a 911. That said, it is a very comfortable interior even with a helmet on and the roof panels in place. Getting in and out isn’t the theatre it is with some exotics and most people should be able to gracefully enter and exit and find a comfortable seating position. There is a single cup holder.

Two lightweight carbon fiber roof panels split apart and lift out, with storage provided in the front luggage compartment. A small air foil can be clipped in place on the top center of the windscreen to reduce buffeting in the cabin and ensure that no exhaust fumes enter from the rear deck. With the roof panels stored in the front trunk there is still a bit of space for some soft luggage, or there is a nice piece of 918 fitted luggage that folds to the necessary triangular shape, and then expands to fill the front compartment if the roof panels are in place.

Infotainment

A nice surprise was a bespoke infotainment system for the 918 Spyder-normally low production volume cars need to make excuses for switchgear and many comfort/convenience items. While the interests of low weight have taken some of the luxury features out of the vehicle, the black glass centre console, instruments and TFT screens are all gorgeous and work much more intuitively and faster than in the regular Porsche production cars. Written in HTML5, like iPads and iPhones, and offering similar drag and-drop and swipe functionality, the elevated centre console features a fully configurable 8” screen that is a joy to use. There is a separate 8” horizontal TFT screen next to the instruments, which are beautifully rendered. The Burmester Stereo sounds rich, although it is best enjoyed in E-Power mode, as the combustion engine will drown out most everything in the cabin.

Porsche 918 at Nurburgring

Driving Impressions

It is hard to convey the accelerative forces the car can provide. I think I could feel my internal organs moving around and my brain slamming into the back of my skull. The weak link in the car’s performance will certainly be the driver, whose physiology will in all likelihood be entirely inadequate to process what is going on underneath him!

With Cass driving on a somewhat damp track, the car just inhaled the strait, going from 100km/hr to 260km/hr in what felt like a few seconds. The difference between the 918 and something like a GT2 RS, my previous fast car benchmark, is that the 918 just feels nailed to the road like a big slot car. Using full throttle in these damp conditions, a 620hp GT2 RS would want to snap 90 degrees sideways and stuff you into the nearest guardrail. The 918 just digs in and goes where it is pointed, there isn’t even any lag with the instant torque of the electric motors. Certainly at speeds that any owner/driver is likely to attain, the 918 Spyder car feels completely planted and forgiving. Porsche runs these events with a professional driver leading in a 991 Turbo S and even with guys like Patrick Long and Walter Rohrl giving it everything they’ve got, the motor journalists were catching them like they were in Miata school cars. Immediately stepping into a 991 Turbo S after the 918, the Turbo S feels much less connected to the track, moving around considerably more with noticeably more body movement. The in-car cameras in the 918 showing the Turbo S lead cars show the drivers working very, very hard to keep a reasonable pace for the journalists in the 918’s.

Porsche currently holds the Nurburgring lap record for a production car at 6:57 with a Weissach Pkg. 918 Spyder (they also hold the outright lap record with a 6:11, a time Stefan Bellof set in 1983 with a Porsche 956 endurance racer) The in-car footage of the 918 record lap doesn’t show Marc Lieb working particularly hard, and the reports are that Walter Rohrl and Timo Kluck also posted sub 7 min times as well. McLaren have stated that they have gone quicker than 7 minutes with their P1, their design objective, but have not released an exact time. Judging by the YouTube videos posted, that car does not look easy to drive on that circuit. Ferrari has not released a time for their LaFerrari either. There is some discussion that chasing Nurburgring times at this level is not relevant, safe or accurate with no formal sanctioning body, and conditions that change significantly day to day. There is a reason that they stopped running Grand Prix races on this track.

But the Porsche 918 Spyder isn’t just a track weapon though, it was designed to be real road car too. Even driving in pure electric mode, E-Power, the car feels rapid, able to accelerate to 100km/hr in about 6 seconds and go on to 150km/hr before the combustion engine kicks in. Certainly fast enough for any traffic situation you are likely to encounter, and there is certainly no way you could unleash the full system power safely in any built up area. It is also quite fun to cruise around on electricity only, as it is a unique sensation to be powerfully whisked away with a Blade Runner soundtrack accompanying you.

You will get as much as 30km from a fully charged Li-Ion battery pack which is slightly more than half as big as the one in the Panamera e-Hybrid. Charging the battery takes about 2 hours plugged into a 220V socket or it can be charged by the combustion engine in as little as 7 minutes on the track or 15-20 minutes on the road. A front axle lift system, Burmester Sound, and rear view camera make the car easy enough to drive in traffic and to park.

The cabin is beautifully finished and the instruments and infotainment systems are elegant and intuitive to use. The car has full Hot-Spot web connectivity when using an iPhone or Android device, so you can use a multitude of web-based radio and other apps including Porsche’s Car Connect which can remotely call up information on the car, lock and unlock doors, set up Geo Fence informing you if the car leaves a pre-set area etc.

Competitive Analysis

2014 is a banner year for the Hypercar, with the debut of 3 very seriously capable machines from Porsche, Ferrari and McLaren. It reminds me of 1988 when the Porsche 959 and the Ferrari F40 faced off on the cover of CAR Magazine, only this time there is a 3rd car worthy of inclusion. In some respects nothing has changed as the 959 and the 918 are both technological tour-de-forces that werecx c designed as a rolling test bed for future technology that will filter down through the range. Just as we saw Twin-Turbo AWD with adjustable dampers and traction control appear in subsequent versions of the 911, we are sure to see Plug-In Hybrid technology, Regenerative braking etc. in future sports cars as well. The Ferrari also has reincarnated its F40 in a sense as the LaFerrari is the simplest and lightest of the trio, and is the closest to a pure race car in concept, with the fewest concessions to ‘real world’ usefulness. The Mclaren is probably closer to the Ferrari than the Porsche in concept, but adds plug-in Battery technology, and some useful electric-only range, though only about half of the Porsches capacity/range.

McLaren P1

737hp 3.8L Twin Turbo V8, 179hp E-motor, 916 total system hp, 664 lb/ft torque, 7sp Double Clutch gearbox, 3,075lbs, RWD, 3kWh Li-Ion battery with Plug-In Capability, 10km electric-only range, production 375 units.

The P1 can be considered an extreme development of the MP4-12C and 650S, and uses a version of those cars Carbon Fiber MonoCell and a development of their 3.8L Twin Turbo V8. McLaren wicks up the boost of the turbo engine to 2.4Bar, about twice the boost of a Turbo S 911. These big turbos would ordinarily create a significant amount of turbo lag, so McLaren has engineered their hybrid components to act as a ‘Torque Fill’, taking advantage of the instantaneous torque that an electric motor provides to fill in the torque curve and give the car a linear power delivery. The McLaren has a very sophisticated and aggressive aero package, which can convert the car to achieve race-car like levels of downforce.

RWD only, the McLaren is reported to be unforgiving to drive, especially in less than perfect conditions. The relatively small battery gives about 10km of electric only range. The P1 has no regenerative braking capability meaning that the kinetic energy of the vehicle is wasted to heat and brake wear upon deceleration. This also limits the P1’s ability to charge its battery on a fast lap, and this limits its power output once the battery charge is depleted.

The concept of the McLaren would appear to be optimized for modern F1 Type race circuits in dry conditions where the car can use its reported 600kg of downforce.

Ferrari LaFerrari

800hp 6.3L V12 with Hy-KERS giving 163hp electric power, 950 total System hp, 664lb/ft Torque, 7sp Double Clutch gearbox, RWD, 2kWh Li-Ion Battery, 2,767 lbs. Production run 499 units.

With no electric-only use, the Ferrari is considered a mild Hybrid as opposed to a full Parallel Hybrid of the other two. The Hy-KERS system is basically a big alternator bolted to the end of the gearbox, which under deceleration will charge a small LI-Ion battery back, and discharging the batteries to add E-Boost to the output shaft of the gearbox when called for.

Because of its positioning the electric motor torque can not take advantage of the torque multiplication of the gearbox. The Hy-Kers system is used to recoup some energy from braking and provide for short periods of E-Boost on the track, similar to an F1 Car.

The LaFerrari concept also appears to be optimized for modern race tracks. It is the lightest car of the trio and the closest to a pure race car conceptually.

Porsche 918 Spyder

608hp 4.6L V8 with 2 electric motors giving 129hp and 154 hp acting on the front and rear axles respectively, total system hp 887, 944 lb/ft torque with >590 from 800-5000rpm. 7 speed PDK double clutch gearbox with electric front wheel drive. 3,700lbs, 6.8 kWh Li-Ion battery with Plug in Capability, 20km electric-only range, Production up to 918 units.

The Porsche 918 WorkshopThe Porsche is a considerably more complicated, heavier machine that relies far more heavily on electrification than the other two. The 918 integrates electric front wheel drive, a second electric motor acting on the rear axle and a much larger Li-Ion Battery pack, giving significantly more electric range. With advanced braking regeneration and a larger battery the 918 can provide more significantly more E-Boost for significantly longer than the other two. The AWD and the open roadster concept make its prodigious performance much more accessible and enjoyable. It is much more a real-world car than the other two.

With much more torque, and AWD to exploit it, as well as a host of chassis technology such as the rear wheel steering and Torque Vectoring, the 918 Spyder will be able to put much more power down to the road much more of the time, making it very likely faster in the real world. It is important to realize that although the other two cars show slightly higher total system Power, they have smaller batteries, meaning they can use this power for a shorter duration. The 918 has more than 3X the electrical storage of the Ferrari and nearly 2X the E-Power, plus a much more aggressive brake regenerative ability.

Summary

For sure these are 3 very exciting machines, and I would argue that they all represent the brand values of their respective manufactures. With Porsche, technology and efficiency have as much influence as outright performance on their vehicle design and this shows with abundance in the 918 Spyder. This is a car that offers a level of performance that pushes the limits of the human body to control it, and yet it can be a reasonably civilized Zero-Emission city vehicle if it needs to be. The level of electrification not only has made the car quicker on the race track, but has made the more accessible and the car more useable.

There have been people who have doubted the idea of a Hybrid Supercar, believing that the electrification would add unnecessary weight, taking away ultimate speed. But consider this; if you removed the approximate 300kg of the Hybrid components, you would wind up with a 3,000lb, 4.6L V8 608hp sports car – similar specs to a Ferrari 458 Speciale, a car that wouldn’t be anywhere close to a 918 in a straight line or on a race track. The engineers at Porsche have proved, beyond a doubt, that Hybrid technology can dramatically improve outright performance.

With far greater development costs, creating nearly every part of the car from scratch, Porsche needed to build the 918 Spyder in a reasonable quantity, yet still wanted a degree of exclusivity. They settled on a target of 918 vehicles, which was significantly higher than the 499 and 375 limits set by Ferrari and McLaren, and with a modestly lower purchase price of $845,000 (USD) vs approximately $1.2M for the McLaren and $1.6M for the La Ferrari. At the time of this writing Porsche has sold about 70% of the production run meaning that they have sold more cars than Ferrari of McLaren so far, and look to sell their intended production run. Porsche will not build an unsold 918 as they did with the Carrera GT, so depending on the market for $1M Supercars, Porsche may cap the production at less than 918 units.

For sure, $1M (CDN) for a sports car is a lot of money, though I would argue that it is a bargain considering the development costs that went into the project. I don’t believe that Porsche could possibly be making a profit on the car, as they didn’t with the 959 or Carrera GT. The 918 is a halo project built to prototype new technologies and it adds relevance to the idea of a Supercar in our current eco-conscious climate. To that end they have succeeded admirably, and come out with an engineering masterpiece.

Lawrence Romanosky

Sales Manager

Porsche Centre Calgary

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