New Audi S4 gets a Supercharged V6

The speculation as to if the new S4 would go back to its turbo charger roots is over. It will receive a new supercharged 3.0 V6 aptly named the 3.0TFSI. At the heart of the upcoming A4/A6, a new 3.0-litre supercharged V6 with direct injection and 1.1 bar boost is expected to produce in the region of 220 kW and 420 N.m of torque between 2500 and 4850 r/min.

Although no details regarding power outputs are known, pundits have suggested 260 kW for the new range-topping variant of the A4. Mated with the new dual clutch S-Tronic transmission, expect the S4 to sprint from zero to 100 km/h in less than six seconds.
Audi says comparative tests showed the mechanical supercharger spins at up to 23 000rpm. It will be released in South Africa in 2009.Audi says comparative tests showed the mechanical supercharger, when combined with direct fuel-injection, gave better performance off idle and more dynamic response, in a more compact package, than a dual-turbo set-up.The Roots-type supercharger is so compact it fits neatly into the vee of the engine; it has a figure-eight shaped chamber with two four-vaned impellers that mesh together as they counter-rotate to push air through the bottom of the casing.It's belt-driven off the crankshaft and spins at up to 23 000rpm to delivering 1000kg of air an hour at a boost pressure of 0.8 bar. The engine has a 10.5:1 compression ratio, also made possible by direct injection; the incoming charge cools the cylinder as it vaporises and helps prevent knock.

Two aluminium, water-to-air intercoolers with their own coolant circuit are built into the compressor housing and the gas paths between compressor and cylinder are very short so torque builds up very quickly, says Audi, enabling it to pull very long gearing.Audi claims it will use less than 10 litres/100km in virtually any longitudinally-engined models, which is what it's intended for.The 90-degree engine block has a bore and stroke of 84.5x89mm for a displacement of 2995cc; the crankcase is reinforced to take the extra thrust on the conrods, the inlet cams can be adjusted through 42 degrees and tumble flaps in the intake ports start the incoming air swirling before it gets to the inlet valves to speed up the mixing process in the cylinder.Audi says the injection hardware is also new, a common-rail system with six-hole injectors that inject the fuel directly into the combustion chambers at 150 bar, with three separate injections per operating cycle to optimise combustion.


Being a big fan of the B5 S4 I loved the twinturbos and I'm not alone, although I enjoyed the V8 there is nothing like the rush of a mildly modified TT S4. I'm sure the new S/C V6 has the intial torque meter of the older S4's but I'm afraid the time of enthusiasts flocking to Audi has come to a stand still.