RUF reveals all-electric Porsche 911 concept

[Plex]

All-electric 911 concept will accelerate from 0-100km/h in just seven seconds

Development of the all-electric Porsche from German tuner RUF has reached a major milestone, with confirmation today that initial testing of a prototype 911 has been successful. RUF had originally planned to install its electric powertrain in its Cayman 3400K model but decided to go with the bigger body of the 997 911 due to better packaging and cooling of the required lithium-ion batteries.

The multiple battery arrays add an additional 550kg to the 911�s mass, bringing the total kerb weight of the electric version to just under 1,900kg. There are a total of 96 battery cells, all supplied by British company Axeon. Despite the substantial increase in weight, the electric motor they power, which is rated at 204 hp (150kW) and 480lb-ft (650Nm) of torque, can accelerate the vehicle from 0-100km/h in a brisk seven seconds and see it reach a top speed of 224km/h.

According to RUF, the car can travel between 250 and 300km between charges. Drive is sent to the rear wheels via the 911�s standard six-speed manual, which reportedly has no trouble dealing with the electric motor.

RUF insists that its all-electric Porsche is still strictly a concept but envisages starting limited production in the not too distant future. Also working on the project is California�s CalMotors, which plans to unveil its own electric concept in the near future. However, like RUF, no production plans have been mentioned.

Motorauthority

[Plex]

Official RUF Automotive GmBH Press Release

"Emotion without Emission"

Ruf Automobile GmbH, internationally well known manufacturer for high performance
automobiles and the producer of the famous CTR-series is now introducing the first
electrically powered sports car from Germany.

The fundamental ideas that lead to the development of the eRUF concept vehicle came from Alois Ruf. The car maker from the Bavarian town of Pfaffenhausen had a vision of a simple energy transfer concept: his hydroelectric power plants, which feed 35 million kW hours of electricity annually into the German electrical network, could also more or less directly power modern autos. 35 million kWh is enough energy to power one of the prototypes eRUF as described below for 3500 journeys around the globe � or 3500 of the cars one time around the world each.

The idea seemed even more inspiring, as it would be possible for him to connect cars directly to the emission-free power plants for charging and drive away on the water-generated power. The eRUF Model A concept car is the first prototype to lead the technical development away from the combustion engine.

Actually, for the first time an electric motor is being used which comes to fitting into the Ruf model range.

The three-phase AC motor's performance easily puts many conventional conbustion engines to shame. It produces its maximum 650 Nm torque output from 0 rpm onwards. This power rips into the drive shafts so impressively during acceleration, that one is immediately reminded of the extremely powerful Ruf Rt 12.

It is actually enough simply to put the car in 6th gear and press down the accelerator pedal (an "amp pedal", not a "gas pedal" in this car!), and drive off. The eRUF Model A has such impressive acceleration that the project goal of 0-100 km/h in under 7 seconds was achieved.

The maximum power output is around 204 hp if you translate it into combustion engine terms. In direct connection to Volt and Ampere the maximum output level of 150 kW is a useful figure.



A short discourse regarding efficiency might be helpful at this point: a highly-developed, modern petrol engine uses around 75 percent of the energy in its tank to heat the engine coolant and exhaust gas and only 25 to 30 per cent for actual propulsion. A diesel manages to convert a respectable 35 to 40 percent of its fuel energy into motion. The permanent magnet electric motor, on the other hand, is a model of high efficiency: it offers over 80 percent efficiency over the majority of its power range, extending 90 per cent in the upper end of its power range.

Ruf engaged CALMOTORS in Camarillo, California, specialized in the implementation of hybrid electric and electric only power train designed to combine the latest generation of lithium-ion batteries with its motor.

Since the 150 kW electric motor unit is very compact, there is a lot of room for batteries in the Ruf's bodywork.

The Axeon iron-phosphate, lithium-ion batteries currently in use weight 5.6 kg and deliver 160 Ah each. This means each one could theoretically deliver 160 amperes of electricity for one hour under normal temperatures or 1 ampere for 160 hours.

The generation of batteries available from Axeon represents by no means the end of the developmental curve. Current performance improvements in battery technology indicate that end of this improvement spiral is nowhere near.



The driving current in the eRUF is regulated by an electric "drive-by-wire" accelerator pedal. It is not the first electrical accelerator in a Ruf model. Other Ruf models also provided load control via potentiometer-pedals, nicely dosed for their powerful engines.

The power and torque produced by the 3-phase motor can be used to recover just as much power as it can put out. When coasting, the motor becomes a generator producing electricity to charge the batteries. The torque and electrical amperage ratings below are therefore to be understood as theoretical absolute maximums and minimums.

The 96-cell battery system is constantly monitored by an intelligent bus system from Axeon. Each individual cell is coupled with a sensor that sends critical information on cell temperature and voltage to the central control system. If irregularities appear during operation, the system can react within milliseconds to bring the values back in line, effectively preventing critical lithium-ion overheating behaviour during charging.



eRUF Concept Model A Electric Porsche 911 Specifications

Drivetrain
Layout: Electric RWD
Transmission: Modifed 6 Speed maintaining feel of standard gear ratios
Differential: Electronically Controlled LSD

Engine
Type: Brushless three phase alternating current with permanent magnets
Batteries Lithium-Ion, iron-phosphate base

Engine & Transmission
Power: bhp (kW) at RPM: Power + 150 kW to -150 kW (peak level) + 204 hp to -204 hp
Torque lb-ft (Nm) at RPM: Max torque + 650 Nm to -650 Nm
Redline at RPM: Rpm level max 5000 rpm

Exterior
Body Type 2 door, 2 seat sports car

Performance
Acceleration 0-60 mph s: Less than 7 seconds
Emissions Just smiles.
Charge Time 10 hours to max. charge
Range 245-320 km, depending on driving style

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