Sunday, November 15, 2009

2009 S4 Audi Sports Car Seven-Speed S-tronic Gearbox Supercharging V6 Engine

2009 Audi S4 Seven-Speed S-tronic

The 2009 Audi S4 is powered by a 3.0 litre V6 with direct fuel injection and what Audi call "mechanical turbocharging" (supercharging), delivers 245 kW (333 hp) yet consumes only 9.7 liters of fuel per 100 km (24.25 US mpg). quattro permanent four-wheel drive, sports suspension and a high-performance brake system control the power reliably. With optional performance technologies - the seven-speed S tronic, the new sport differential and the Audi drive select dynamic driving system - both new S models from Audi are extending their lead even further.
It takes just two figures to comprehend the dynamic potential of the new Audi S4 and S4 Avant: 5.1 seconds for the sprint from zero to 100 km/h (62.14 mph) and only 4.4 seconds for the intermediate sprint from 80 to 120 km/h (49.71 - 74.56 mph) in fourth gear. Behind these figures there is a fascinating driving experience, marked by the sonorous sound of the new mechanically supercharged V6 engine, its mighty propulsive power, its free-revving character and its sharp, spontaneous response to the throttle.
2009 Audi S4 Seven-Speed S-tronic

The 3.0 TFSI is the new range-topping unit in Audi's V6 engine family. It Develope 333 horsepower and 324 lb-ft (440 Nm) of torque at 2,500 rpm, the engine is connected to either a standard six-speed manual gearbox, or an optional seven-speed, dual-clutch transmission which can be used either as a conventional automatic or as a sequential semi-auto with steering wheel mounted paddles.
Now the supercharger is staging a comeback - the T in the engine description no longer stands for the turbocharger alone. Extensive comparative tests revealed the mechanical supercharger to be superior to a biturbo concept for the big V6 engine. In conjunction with direct injection this concept has clear advantages in terms of the prioritized features of packaging, starting performance and responsiveness.
The supercharger is so compact that is easily accommodated in the 90-degree V of the cylinder banks, in place of the intake manifold. The engine-driven Poly-V belt that powers the mechanical turbocharger provides full thrust right from idling speed. The 3.0 TFSI delivers its maximum 440 Nm (324.53 lb-ft) at only 2,900 rpm and maintains this constantly until 5,300 rpm. The intermediate sprint from 80 to 120 km/h (49.71 to 74.56 mph) is completed in fourth gear in 4.4 seconds; even in sixth gear it takes a mere 7.1 seconds.
2009 Audi S4 Seven-Speed S-tronic

The seven-speed S-tronic gearbox of the 2009 S4 consists of two separate transmissions and uses two multidisk clutches that control the various gears. The large K1 clutch guides the power via a solid shaft to the pinions for gears 1, 3, 5 and 7. A hollow shaft rotates around the solid shaft; it is connected to the compact K2 clutch, which is integrated within its larger counterpart and controls the pinions for gears 2, 4, 6 and reverse gear.
Both transmission structures are continuously active, but only one is powered at a time by the engine. The quattro all-wheel-drive system sends power to all four wheels. A 40/60 percent front/rear torque bias ensures that the handling remains sporty yet stable. However, when necessary, the power distribution can be varied within fractions of a second.
The gas paths after the supercharger are very short which is why the 3.0 TFSI builds up torque extremely quickly when accelerating, even more dynamically than a naturally aspirated engine of the same displacement. The 3.0 TFSI responds directly to the throttle in true sporty fashion, is agile and sprightly, revving up to the maximum of 7,000 rpm with playful ease.
2009 Audi S4 Seven-Speed S-tronic

The 2009 Audi S4 shares the same styling cues as the rest of the model lineup. Some of the most striking modifications to the exterior design are the special aprons, the aluminum-look exterior mirrors, the 18-inch S-design light-alloy wheels, the side rocker panels, the discreet rear spoiler and the quadruple exhaust system. The xenon plus headlights with daytime running lights and the rear lights are further distinctive touches.