Audi has unveiled its latest S6 and S7 models for 2019, and for the first time the OEM has deployed an electric powered compressor with a 48V primary electrical system.
Equipped with a V6 TDI engine, the new S6 and S7 will develop peak torque of 700Nm at a speed range of 2,500 to 3,100rpm and maximum power output of 353ps. Power transmission is handled by the OEM’s eight-speed tiptronic automatic.
The V6 TDI weighs around 190kg and its common-rail system injects fuel at a pressure of up to 2,500 bar. The unit has also been developed to make the most of the latest in ICE technology. This means that the crankshaft, pistons, connecting rods and oil management meet high-performance requirements, and measures have been taken to reduce friction in the crankshaft and camshaft drive.
In addition the cooling circuits of the crankcase and cylinder heads are kept separate so that the engine oil warms up rapidly from a cold start. The coolant flow is directed to the oil cooler, the EPC, the BAS and the compressor case of the turbocharger as needed.
The exhaust turbocharger, with a turbine wheel measuring 50mm in diameter, generates a relative boost pressure of up to 2.4 bar. Its variable turbine geometry (VTG) is optimized for low-loss flow. The external low-pressure exhaust gas recirculation (EGR) only draws off the exhaust gas after the particulate filter so that the full mass flow can power the supercharger, significantly increasing its effectiveness.
