Encounter - The Audi Technology Magazine 2/2013
3.0 TDI BITURBO
The most powerful member of the V6 TDI family is conceived as a biturbo – the two turbochargers are arranged in series and connected by a changeover valve. At low revs, the valve is closed; the small high-pressure charger with its variable turbine geometry does most of the work, while the large low pressure charger handles pre-compression. Upward of about 2,500 rpm, the valve begins to open and the small turbo gradually transfers the main workload to its large counterpart. In the range between 3,500 and 4,000 revs, the valve is fully open and only the large turbocharger is operating. The substantial performance of 230 kW (313 hp) and 650 Nm of torque called for far-reaching modifications to the 3.0 TDI biturbo and its peripherals. A sound actuator in the exhaust system gives the three-liter diesel a rich, sonorous tone.