Exagon's 155 mph Furtive-eGT electric supercar
By David Szondy
March 11, 2013
Electric cars haven’t exactly stolen the limelight at this year's Geneva Motor Show, but Exagon Motors is bucking the trend with the highly customizable, “haute couture” Furtive-eGT electric sports car.
Previously shown at the Paris Motor Show, the Furtive-eGT, Exagon hopes to bring back the days of the 1930s when car makers displayed a high degree of customization. Then, it was common for customers to buy a chassis and engine from one company and have another design and construct the body. Since for Exagon this means adjusting some 6,000 components to suit customer desires, the company only makes about 100 hand-assembled Furtive-eGTs per year.
.At first glance, the Furtive-eGT seems a pretty modest machine for an electric GT, seeming little more than a wedge with a curiously pursed snout marked by a tiny grille. It isn't until the eye runs along the profile that the distinct “double bubble” roof and splaying side wings stand out. The 124 kilograms (273 lb) body is a carbon fiber honeycomb monocoque with a carbon fiber floor designed to hold the battery and provide a low center of gravity. Sitting centrally in respect to the wheels, this is aimed at ensuring greater stability and in turn, better cornering and braking.
According to Exagon, this type of construction is used on only seven other supercars and none of those are electric. The company says that the design provides exceptional torsional stiffness for better lateral grip and neutral behavior. It directly supports the front half-axles and in the rear, a cast-aluminum structure supports the powertrain and half-axles.
The Furtive-eGT uses LEDs for all lighting and signalling, features a carbon, aluminum and leather interior and the a multimedia infotainment system developed in partnership with Nokia that includes a nine-inch central capacitive touch screen with swipe and zoom functions working in conjunction with a ten-channel sound system.
The rear-wheel drive electric sportscar is driven by two Siemens 148 kW (198 bhp) electric motors with 516 Nm (380 ft-lb) of torque which are mounted on an aluminum cradle at the rear of the car. These motors are linked by electronic controls that allow them to work in unison or separately. According to Exagon, they’re the most compact on the market – liquid cooled with a response time of one-tenth of a second, they are billed as having a high level of reliability with no maintenance required before reaching 150,000 kilometers (93,205 miles).
The powertrain is completed by a self-locking differential and the ZTI three-speed semi-automatic gearbox designed for seamless torque delivery. Unlike sequential gearboxes, has no danger of breaking the clutch because there isn't one. As the gear changes, one or both motors continues to power the wheels, allowing the motors to operate continuously within the optimum range of power and efficiency. Reverse gear is achieved by reversing the motors.
Top speed is limited to 250 km/h (155 mph) with acceleration of 0 to 100 km/h (62 mph) in 3.5 seconds. The power to weight ratio is 4.08 kg/bhp.
Braking on the Furtive-eGT is a bit different than on a conventional car. There are vented Beringer steel discs with six-piston calipers front and four-piston calipers rear, but much of the 1.2 g deceleration is achieved by the electric motors, which recharge the batteries as the car slows.
Exagon claims that the Furtive-eGT is suitable for both day-to-day and sport driving with four operating modes – Standard for full power and optimized gear changes, Eco for extended range and the inexperienced driver, City for low speed and smooth riding with improved air recycling, and Sport for performance driving with the emphasis on acceleration and gear response.
The battery pack is a lithium-ion system made by Saft, a major supplier to aerospace, defense and Formula 1 customers. It weighs 450 kilograms (992 lb) and has a capacity of 53 kWh, providing a claimed range of 360 kilometers (223 miles) in the city. According to Exagon, it can charge over 3,000 cycles in ten years and retain 80 percent of capacity with no memory effect. In fast recharge mode, the battery can reach between 30 and 80 percent charge in 32 minutes.
The Furtive-eGT is now available for order and the first deliveries are expected by the end of the year. Pricing, as you may have guessed by now, is stratospheric – around €350,000 (US$450,000).
The Geneva Motor Show runs March 7 to 17.
The video below shows the Furtive-eGT being tested on the Nürburgring
Source: Exagon Motors