posted in Autofan EV / Hybrid section March 3, 2017

Porsche 918 Spyder - The Last Porsche Made Spyder Car

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Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car Porsche 918 Spyder - The Last Porsche Made Spyder Car

Base from $845,950 Gas Engine: 4.6 L V8 - 608 hp at 8,600/min
Base + Weissach Package from $929,950 Front Axle Electric Motor: 127 hp
Top speed: 211+ mph Rear Axle Electric Motor: 154 hp
Electric Top Speed: 93 mph Combined Horsepower: 887 hp @ 8,700 rpm
Electric Range: 18 miles Torque: 944 lb-ft
Acceleration: Curb weight: 3,602 to 3,692 lbs
 0-60 mph less than 2.8 seconds Dimensions: 183'L x 76'W x 46'H
 0-62 mph (in electric mode) 7.0 seconds Fuel tank capacity: 18.5 gal
 0-124 mph (0-200 km/h) 7.9 seconds Battery: 6.8 kWh lithium-ion
 0-186 mph (0-300 km/h) 23.0 seconds Transmission: 7-speed auto-shift manual w/OD

The Porsche 918 Spyder is a mid-engine, plug-in hybrid sports car by Porsche. Strictly limited to only 918 units and assembled in a 4000-square-metre manufacturing facility in Zuffenhausen, Germany by 100 selected employees by hand. Production began on September 18, 2013, with deliveries initially scheduled to begin in December 2013. The Porsche 918 Spyder was sold out in December 2014.

The 918 Spyder embodies the essence of the Porsche idea: it combines pedigree motor racing technology with excellent everyday utility, and maximum performance with minimum consumption. The task faced by the development team was to create the super sports car for the next decade with a highly efficient and powerful hybrid drive. The entire car was designed around the hybrid drive. The 918 Spyder therefore demonstrates the potential of the hybrid drive to a degree never seen before: the parallel improvement of both efficiency and performance without one being at the cost of the other. This is the idea that has made the Porsche 911 the most successful sports car in the world for 50 years. In short, the 918 Spyder will act as the gene pool for the Porsche sports cars of the future.

The 918 Spyder reveals its close links to motorsport in a variety of ways. A great deal of insight gained from the development of Porsche race cars for the 24 hours race in Le Mans in 2014 is thus integrated into the 918 Spyder - and vice versa. The structural concept of the 918 Spyder with a rolling chassis as its basis - a basic vehicle that can be driven even without a body - is race car tradition at Porsche. The concept of the V8 engine originates from the LMP2 RS Spyder race car. The load-bearing structures, the monocoque and subframe, are made of carbon fiber reinforced polymer. Many parts of the super sports car come from manufacturers who have a proven record as suppliers for motorsport vehicles.

The uniqueness of 918 Spyder is that the hybrid drive from Porsche is a plus for no-compromise driving dynamics. Drivers can experience this thanks to the unique all-wheel drive concept with a combination of combustion engine and electric motor on the rear axle and the second electric motor on the front axle. The energy storage system is a 312-cell, liquid-cooled 6.8 kW•h lithium-ion battery positioned behind the passenger cell. In addition to a plug-in charge port at the passenger-side B-pillar, the batteries are also charged by regenerative braking and by excess output from the engine when the car is coasting.

The drivetrain components and all components weighing over 110 lbs. are located as low and as centrally as possible within the vehicle. This results in a slightly rear end biased axle load distribution of 57 percent on the rear axle and 43 percent on the front axle, combined with an extremely low center of gravity at approximately the height of the wheel hubs, which is ideal for driving dynamics. The central and low position of the traction battery directly behind the driver not only supports efforts to concentrate masses and lower the center of gravity; it also provides the best temperature conditions for optimum battery power capacity.

The entire load-bearing structure is made of carbon fiber reinforced polymer (CFRP) for extreme torsional rigidity. Additional crash elements at the front and rear absorb and reduce the energy of a collision. The car's unladen weight of approximately 3,715 lbs. (3,616 lbs. with "Weissach" package), an excellent low weight for a hybrid vehicle of this performance class, is largely attributable to this concept.

Porsche Active Aerodynamic (PAA), a system of adjustable aerodynamic elements, ensures unique and variable aerodynamics; its layout is automatically varied over three modes ranging from optimal efficiency to maximum downforce and is tuned to the operating modes of the hybrid drive system. In "Race" mode, the retractable rear wing is set to a steep angle to generate high downforce at the rear axle. The spoiler positioned between the two wing supports near the trailing edge of the airflow also extends. In addition, two adjustable air flaps are opened in the underfloor in front of the front axle, and they direct a portion of the air into the diffuser channels of the underbody structure. This also produces a "ground effect" at the front axle.

In "Sport" mode, the aerodynamic control system reduces the attack angle of the rear wing somewhat, which enables a higher top speed. The spoiler remains extended. The aerodynamic flaps in the underfloor area close, which also reduces aerodynamic drag and increases attainable vehicle speeds. In "E" mode, the control is configured entirely for low aerodynamic drag; the rear wing and spoiler are retracted and the underfloor flaps are closed.

Adjustable air inlets under the main headlights round off the adaptive aerodynamic system. When the vehicle is stationary and in "Race" and "Sport" mode, they are opened for maximum cooling air intake. In "E-Power" and "Hybrid" modes, they close immediately after the car is driven off in order to keep aerodynamic drag to a minimum. They are not opened until the car reaches speeds of approximately 81 mph or when cooling requirements are higher.

The core of the 918 Spyder concept is its distribution of propulsive power among the three power units; their cooperation is controlled by an intelligent management system. To best exploit these different approaches, the Porsche developers defined five operating modes that can be activated via a "map switch" on the steering wheel, just like in motorsport cars. On the basis of this pre-selection, the 918 Spyder applies the most suitable operating and boost strategy without driver intervention, thus allowing the driver to concentrate fully on the road.

Quiet and elegant: "E-Power"

When the vehicle is started up, the "E-Power" mode is the default operating mode as long as the battery is sufficiently charged. In ideal conditions, the 918 Spyder can cover approximately 18 miles on purely electric power. Even in pure electric mode, the 918 Spyder accelerates from 0 to 62 mph in seven seconds and can reach speeds of up to 93 mph. In this mode, the combustion engine is only used when needed. If the battery's charge state drops below a set minimum value, the vehicle automatically switches to hybrid mode.

Efficient and comfortable: "Hybrid"

In "Hybrid" mode, the electric motors and combustion engine work alternately with a focus on maximum efficiency and minimum fuel consumption. The use of individual drive components is modified as a function of the current driving situation and the desired performance. The Hybrid mode is typically used for a fuel economy-oriented driving style.

Sporty and dynamic: "Sport Hybrid"

In more dynamic situations, the 918 Spyder selects the "Sport Hybrid" mode for its power sources. The combustion engine now operates continuously and provides the main propulsive force. In addition, the electric motors provide support in the form of electric boosting or when the operating point of the combustion engine can be optimized for greater efficiency. The focus of this mode is on performance and a sporty driving style at top speed.

For fast laps: "Race Hybrid"

"Race Hybrid" is the mode for maximum performance and an especially sporty driving style. The combustion engine is chiefly used under high load, and charges the battery when the driver is not utilizing its maximum output. Again, the electric motors provide additional support in the form of boosting. Furthermore, the gear-shifting program of the PDK is set up for even sportier driving. The electric motors are used up to the maximum power output limit to deliver the best possible performance for the race track. In this mode, the battery charge state is not kept constant, rather it fluctuates over the entire charge range. In contrast to Sport Hybrid mode, the electric motors run at their maximum power output limit for a short time for better boosting. This increased output is balanced by the combustion engine charging the battery more intensively. Electric power is thus available even with several very fast laps.

For pole position: "Hot Lap"

The "Hot Lap" button in the middle of the map switch releases the final reserves of the 918 Spyder and can only be activated in "Race Hybrid" mode. Similar to a qualification mode, this pushes the traction battery to its maximum power output limits for a few fast laps. This mode uses all of the available energy in the battery.

Main Power: 

The main source of power is the 4.6-liter, eight cylinder engine that produces 608 hp of power. The engine is derived directly from the power unit of the successful RS Spyder, which explains why it can deliver engine speeds of up to 9,150 rpm. Like the race engine of the RS Spyder, the 918 Spyder power unit features dry-sump lubrication with a separate oil tank and oil extraction. To save weight, components such as the oil tank, the air filter box integrated into the subframe and the air induction are made of carbon fiber reinforced polymer. Further extensive lightweight design measures have resulted in such features as titanium connecting rods, thin-wall, low-pressure casting on the crank case and the cylinder heads, a high-strength, lightweight steel crankshaft with 180 degrees crankpin offset and the extremely thin-walled alloy steel/nickel exhaust system. Striking features of the V8 are that it no longer supports any auxiliary systems, there are no external belt drives and the engine is therefore particularly compact. Weight and performance optimizations achieve a power output per liter of approx. 133 hp/l - the highest power output per liter of a Porsche naturally aspirated engine - which is significantly higher than that of the Carrera GT (106 hp/l) and outstanding for a naturally aspirated engine.

Transmission: Doppelkupplung

A seven-speed Doppelkupplung (PDK) transmission handles power transmission to the rear axle. The high-performance transmission is the sportiest version of the successful PDK; it has undergone a complete redesign for the 918 Spyder and has been further optimized for high performance. To ensure a low mounting position for a low center of gravity of the entire vehicle, the gear unit was turned "upside down" by rotating it 180 degrees about its longitudinal axis, in contrast to other Porsche series. If no power is required on the rear axle, the two motors can be decoupled by opening the decoupler and PDK clutches. This is the action behind the Porsche hybrid drive's typical "coasting" with the combustion engine switched off.

Recalls and issues

On July 28, 2014 a recall was issued for all Porsche 918 vehicles manufactured between May 7, 2014 and June 18, 2014 due to, "rear-axle control arms that may break, causing difficulty controlling the vehicle."

Later that year, on December 23, 2014, another recall was issued for all Porsche 918 vehicles that were manufactured from February 25, 2014 to September 18, 2014 as the, "front lower control arms may fracture." The NHTSA stated that, "fracture of a lower control arm while the vehicle is being driven increases the risk of a crash." Remedy parts were not expected to be available until the end of February, 2015.

On June 1, 2015 a third recall was issued for the car due to fact that, "the wiring harness for the left rear radiator fan may contact an engine heat insulation plate." The consequence of this being, "If the harness contacts the insulation plate, the harness may chafe and result in an electrical short which could increase the risk of a fire." Porsche requested that owners leave the car parked outside until the remedy is implemented.
by Greg Mc Kenzie
Independent Contributor


source: Porsche USA

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