The revered RS badge is about to adorn a compact class Audi for the first time as the new RS 3 Sportback waits in the wings with suitably spectacular performance and an evocative five-cylinder soundtrack for a spring 2011 UK debut. The formidable yet usefully practical newcomer will be available to order in the UK from next month priced at £39,900 OTR.
Audi high performance engineering division quattro GmbH takes the five-door Sportback version of the A3 as the foundation for the latest RS model, and in deference to the classic quattros of the Eighties endows it with a turbocharged five-cylinder petrol engine that employs 21st Century TFSI turbo charging and direct injection technology.
First seen in the TT RS, this all-new unit fills the cabin with a rich, bass-heavy five-cylinder tone as it channels 340PS and 450Nm of torque to the road through a standard seven-speed S tronic twin-clutch transmission and quattro all-wheel-drive. A sound flap in the exhaust branch intensifies the sound even further when the driver presses the Sport button, which also varies throttle response.
Maximum torque is readily available at the low end of the rev range, from around 1,600 rpm, and remains constant up to 5,300 revolutions, making for excellent flexibility and response.
The large turbocharger generates up to 1.2 bar of boost pressure, and downstream of it is an intercooler which achieves an efficiency rate of more than 80 per cent. The combination of the latest forced induction technology with FSI direct injection facilitates a high compression ratio (10.0:1) along with a correspondingly high efficiency ratio. Flaps in the intake tract mix the air as it flows in. The two camshafts, each adjustable by 42 degrees of crankshaft rotation, also enhance the efficiency of the mixture formation.
As befits an RS model the impressive output of this engine is reflected in an exceptional 0-62mph sprint time of just 4.6 seconds and an electronically governed 155mph top speed. Yet less predictably, this rapidity doesn’t rule out the potential for up to 31mpg according to the combined cycle test.
Carbon fibre aids weight reduction
The efficiency of the RS 3 Sportback is due in large part to a delivery-on-demand oil pump and a regenerative system that recovers energy as the car decelerates, but is also facilitated by weight-saving measures including the use of strong but light vermicular graphite for the engine block and carbon fibre-reinforced plastic (CFRP) for the front wings. These help to keep the kerb weight of the new RS 3 down to 1,575kg, to keep CO2 output down to 212g/km and, equally importantly, to elevate the power-to-weight ratio to an impressive 216PS per tonne.
The extreme performance is gainfully employed by a chassis that lowers the RS 3 Sportback by 25mm compared with the standard A3, and comprises McPherson struts upfront and a four-link rear set-up. Balance and composure are boosted by a widened, 1,564 millimetre track, and grip by 19-inch alloy wheels shod with 235/35 series tyres at the front and 225/35 at the rear. The standard wheel finish is a machine-polished titanium look, but a black finish with red rim inserts is also available as an option.
Highly efficient electromechanical rack-and-pinion steering provides a suitably direct gear ratio of 16.2:1 for keen turn-in, while internally ventilated disc brakes measuring 370 millimetres in diameter at the front and 310 millimetres at the rear modulate speed powerfully and progressively. Their aluminium covers are encircled by four-piston fixed calipers painted a high-gloss black and bearing RS logos. To support them, the electronic stability programme (ESP) features a Sport mode that activates later intervention of the braking and acceleration retardation functions to enable greater adjustability without compromising safety. It can be switched off entirely for circuit use.
The quattro permanent all-wheel drive system oversees proceedings, granting the RS 3 Sportback an extra measure of traction, composure and stability. Its central component is an electronically controlled multi-plate clutch, mounted at the end of the propeller shaft to achieve a favourable axle load distribution. Located in its interior is a plate package bathed in oil.
Thanks to quattro, the propulsive power can be distributed to each axle as needed. Whenever slip occurs at one of the axles, an electric pump intervenes at lightning speed to increase the oil pressure. The pump presses the clutch plates together, thereby permitting the torque to be redirected accordingly. Thanks to a powerful accumulator, this process takes just a few milliseconds.
