The new `Quickshift' version of the six-speed ZF 6HP26 automatic transmission is engineered exclusively for the Continental Supersports. Shift time has been cut by 50 per cent and the revised transmission also helps double downshifts (e.g. 6th down to 4th)
During upshifts, fuel and ignition are cut momentarily to give faster mechanical shift times through torque reduction, also improving shift quality and durability. Positive torque during downshifts is achieved through engine and gearbox electronic controller interaction for extra throttle and fuel injection during the overrun. This replicates manual throttle `blips' for precise rev matching and helps double downshifts for enhanced response.
Acceleration times are improved, response times throughout the whole gear range are enhanced and engine braking can be better exploited during enthusiastic driving. The result is a driving experience with a sportier feel and sound.
To cope with the additional power and torque, the planetary gear set of the ZF transmission is also strengthened.
The increased power and torque, `Quickshift' transmission and a 110 kg reduction in weight endow the Supersports with a top speed of 204 mph (329 km/h) and a 0-60 mph sprint time of just 3.7 seconds (0-100 km/h in 3.9 seconds). It also accelerates from 0-100 mph (0-160 km/h) in just 8.9 seconds.
Engineering Bentley's first `FlexFuel' engine
At the 2008 Geneva Auto Salon, Bentley announced a far-reaching environmental program to reduce CO2 emissions and improve fuel economy across its model range.
An important element of this strategy is by 2012 to make the entire Bentley fleet capable of running on renewable fuel through the introduction of FlexFuel technology, where engines are capable of running seamlessly on bioethanol, petrol or any mix of the two.
At the same time Bentley declared that this would be achieved without sacrificing its well-known performance and luxury.
This statement of intent has taken shape in the Continental Supersports - a car that balances extreme potency with the pioneering use of biofuel technology in the luxury sector.
The result is a net CO2 reduction of up to 70 per cent on a well-to-wheel-basis, the measurement of CO2 release of a fuel from its production (well) to its combustion or deployment (wheel).
Bioethanol can be derived responsibly from crops such as corn, soybeans, sugarcane and switchgrass. Second generation bioethanol uses the non-food fibers of the plant (biomass), as well as agricultural waste and forestry residues. These are collected and refined into cellulose ethanol.
CO2 is absorbed by plants as part of the photosynthesis process, and cars using biofuel then release that CO2 back into the atmosphere, thus creating an unbroken energy cycle. In addition, biofuels are not derived from fossil fuels, making them a renewable resource ensuring a secure supply into the future.
Bioethanol is often blended with petrol in a variety of percentages ranging from E10 (10% bioethanol) to the most widely known, E85, blended to a ratio of 85 per cent bioethanol to 15 per cent petrol to ensure cold-start capability.
Bioethanol presents unique engineering challenges compared with petrol, due to its chemical composition and characteristics. E85 biofuel has a very high octane rating of 105 but a lower energy content that requires a 30 per cent 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 corrosive properties of ethanol.
For the fuel system all O-rings, seals, gaskets and pipes are new. In addition, increased fuel flow is achieved through a returnless fuel system and twin variable flow fuel pumps for the engine. The use of bioethanol also requires new valve coatings and hardened valve seat material for additional lubrication, a new closed-loop fuel rail design with pressure sensor for higher fuel flow rates and new spark plugs with a wider heat range for slower combustion.
The W12 6-litre power unit has the technology to run on petrol, E85 or any mix of these two fuels.