Despite being a mainstream product, the new Audi RS3 has the specification of a really hot sports car until you come to the all-steel body (apart from fenders). Still, this is a ferociously hot hatch, capable of reaching 60 mph in 4.5 seconds, and accelerating very quickly to a limited top speed of 155 mph (250 km/h).
Powered by the 2.5 liter five-cylinder engine first used in the Audi TT RS, the new hot hatch is sure to surprise a few people driving much expensive sporty vehicles. To get the power to the wheels, the SR3 has quattro four-wheel drive.
There is plenty of performance, but despite thesporty grille, the hatchback looks rather tall and dull, which will appeal to those who want to be able to surprise people with their car's power.
Unlike most modern engines, the five-cylinder 2,480 cc unit has a cast iron cylinder block, albeit of vermicular graphite cast iron, which is stiffer and stronger than normal cast iron, and can be cast with thinner walls. Audi has designed the engine so that it is very short, just 19.29 inches (490 mm) long, and the weight is quoted as 403 lb (183 kg) which is not that light for an engine of this size. This is the inevitable result of using the iron block.
Power of a compact supercar
Even so, it is the engine which is the star of the RS3, developing 340 bhp (250kW) at 5,400-6,500 rpm, while maximum torque of 332 lb ft (450 Nm) is available all the way from 1,600 to 5,300 rpm, as is pretty normal for the latest generation of turbo engines. A few years ago this would have been giving the torque of a diesel with the power of near racing engine.
That's progress, and results from the combination of 1.2 bar boost, 10:1 compression ratio, direct injection and variable valve timing. Yes, you need all that stuff to build a low-emission, tractable, high-performance engine these days.
The power output is equivalent to 137 bhp per liter, which, while nowhere near the specific output of the McLaren MP4-12C (157 bhp per liter) is pretty hot for a mainstream company like Audi.
To reduce losses in the engine, there is an electrically driven oil pump, which comes into operation only when needed, whereas normally the oil pump is driven all the time.
7-Speed Sequential Box and -
To get the most out of the engine, it is coupled to a twin-clutch seven-speed paddle-controlled sequential box, which can operate in either manual or automatic mode. There are two modes in automatic, normal and sporty, and one in manual. Seven-speed boxes are now as good as it gets in supercars, too.
- Quattro four-wheel drive
Then, to get the power to the road, the RS3 has quattro four-wheel drive of the type used on several other Audis. It consists of a center differential which has a wet clutch controlled electronically to produce the right amount of torque to the front and rear wheels whatever the conditions. This overcomes the problem of the bias of the weight to the front on almost any car built initially for front wheel drive. The result is that the car will probably not be very chuckable.
The suspension is based on that of the A3, but is lowered and stiffened. To provide plenty of grip, the front tires are wider than the rear, and 19-inch wheels are used. The tire sizes are 235/35 on the front, and 225/35 at the rear.
So here is a really hot and compact hatch, with almost the same performance as the Audi TT RS. Good news for hot hatch fans, or anyone wanting supercar performance in a car that looks almost ordinary, except for those flared fenders, made from carbon fiber reinforced plastic.
