|The Supersports Convertible. Click to enlarge.|
Bentley will introduce its new FlexFuel capable Supersports Convertible at the upcoming Geneva Motor Show. The Supersports Convertible, with the same 621 bhp (463 kW) twin-turbocharged W12 engine as the Coupé version introduced in 2009, is the fastest and most powerful drop-top Bentley has ever built, and can run on both gasoline and E85 bioethanol or any combination of the two.
The standardization of FlexFuel technology across the 2011 Continental model range reaffirms Bentley’s ongoing commitment to make all its cars bio-fuel compatible by 2012. The Bentley FlexFuel system keeps power and torque constant whatever the ratio of gasoline to E85 biofuel.
E85 biofuel has a very high octane rating of 105 but a lower energy content compared to gasoline that requires a 30% increase in the engine fuel flow rate. This necessitated a complete review of the fuel system to identify and, if required, replace components deemed to be insufficiently resistant to the properties of ethanol.Increased fuel flow is achieved through a returnless fuel system, twin variable flow fuel pumps and a new closed loop fuel rail design with pressure sensor. For the fuel system all O-rings, seals, gaskets and pipes are new while new valve coatings and hardened valve seat material provide additional lubrication. New spark plugs with a wider heat range allow for slower combustion.
A Fuel Quality Sensor detects the blending ratio of the fuel in real time sending a signal to the engine control unit (ECU), initiating the correct engine mapping. This ensures all performance parameters remain balanced and consistent. The FlexFuel technology used on the Continental model range offers a reduction of up to 70% in CO2 emissions on a well-to-wheel basis, according to Bentley.
The 6-liter W12 engine twin-turbocharged engine produces 621 bhp (463 kW) at 6,000 rpm and 800 N·m (590 lb-ft) of torque at 2,000-4,500 rpm. The engine is coupled with an uprated and rapid six-speed ZF 6HP26 Quickshift transmission, which more than halves shift times (to 93 milliseconds) and maximizes the new Convertible’s potential. The revised gearbox also has the ability to deliver double downshifts (sixth to fourth gear, for example) and improves acceleration across the entire gear range. To cope with the additional power and torque, the planetary gear set of the ZF transmission is also strengthened.
Positive torque during downshifts is achieved through engine and gearbox electronic controller interaction for extra throttle and fuel injection during the overrun. During transmission upshifts, fuel and ignition are cut momentarily to give faster mechanical shift times through torque reduction, also improving shift quality and durability.
A new 40/60 rear-biased torque split for the all-wheel drive system reduces understeer when powering out of bends and provides for better modulation of line and attitude by throttle steering.
|The inspiration for the Supersports name is the 1925 Bentley Supersports, a race-bred version of the iconic Bentley 3-liter, that delivered 85 bhp when more ordinary cars were equipped with a modest 15 bhp. It was also the first production car to reach 100 mph—extreme performance in its day.|
The increased power and torque of the W12 engine necessitated an additional 10% airflow to the twin turbocharger intercoolers and cooling system. Bentley’s designers responded with a purposeful style, featuring large vertical intake apertures. Twin hood vents were added to ensure positive air extraction.
The Continental Supersports Convertible is the fastest drop-top Bentley has built: 0-60 mph in 3.9 seconds (0-100 km/h in 4.2 seconds) and a top speed of 325 km/h (202 mph). It is also the fastest four-seat convertible in the world.
Bentley is a member company of the Volkswagen Group.