Audi displayed this turbodiesel-powered Audi R8 at the 2008 Detroit Auto Show earlier this month. Peek through the rear hatch where the engine bay is and you will see the huge 6.0 litre V12 TDI turbodiesel engine based on the 5.5 litre V12 TDI engine used in Audi’s 24 Hours of Lemans 2006 and 2007 winner, the Audi R10 race car. The engine is mated to a 6-speed manual gearbox.
This road-going, Euro VI-compliant version of the engine is built at Audi’s Gyor plant in Hungary, and puts out 500 horsepower and 1,000Nm of torque from as low as 1,750rpm, just over idle speed! This massive amount of power and torque sends the Audi R8 V12 TDI to 100km/h in just 4.2 seconds. Putting all that torque to the wheels is Audi’s famous quattro system, sending power to all four wheels in a 40:60 front to rear ratio. The engine bay is illuminated at night with LEDs and can be seen through the rear glass hatch.
The V12 TDI’s crank case is made of gray cast iron with vermicular graphite, a material that Audi calls GJV-450. Audi is already using it in its V6 TDI and V8 TDI engines. This material is 40% more rigid and 100% more fatigue-resistant than conventional gray cast iron. This allowed Audi to make the engine block thinner, cutting weight by 15%.
The mind-boggling grand total of 1000Nm of torque between 1,750rpm and 3,000rpm are thanks to two variable turbine turbochargers located outside of the V bank that blow up to 2.6 bar of boost pressure into the two banks of cylinders. These turbos have two large intercoolers. Exhaust exists from each turbo into its own exhaust system – this means twin exhaust and even twin particular filters.
The cylinder head is made from 3 main elements, a high-strengh aluminium alloy base, an oil bearing upper section and a reinforcing ladder frame supporting the two camshafts. Low-friction roller cam followers actuate the 4 valves per cylinder, and cylinder compression ratio is 16.0:1. Diesel is injected via a Bosch common rail system featuring two new dual-piston high pressure pumps and eight-hole nozzle piezo injectors, injecting with a pressure of up to 2,000 bar.
The piezo injectors can inject up to 5 fuel operations per cycle. Other than main injection, pilot and post injections are possible. Pilot injections tone down the acoustic harshness of the combustion process. Post injections are designed specifically to increase the temperature of the exhaust gas for the two standard particulate filters.
I cannot even begin to imagine 1,000Nm of torque, all of which you can feel during acceleration because they are put down to the ground efficiently thanks to quattro. I just can’t. Can you? More photos after the jump.