A time of 4.2 seconds to accelerate to 100km/h is nothing to write home about in these enlightened times.
But it is if the car achieving that time is diesel-powered. Enter the Audi R8 V12 TDI Concept.
Audi has built the special R8 — finished in Grace Silver — for the North American International Auto Show in Detroit. It’s not as if the R8 isn’t stunning in petrol-powered production form ), but the diesel concept is a monster, with its V12 displacing 5.9 litres and developing 1000Nm of torque, on tap from 1750rpm to 3000rpm. As well as the acceleration this engine affords, it will also drive the R8 concept up to a top speed of 300km/h, according to Audi.
The acceleration time shaves 0.4 seconds off the time set by the R8 4.2 FSI quattro, which produces a 430Nm of torque at much higher engine speeds (4500 to 6000rpm).
With two diesel particulate filters and an aqueous urea reservoir, the concept car also meets the Euro 6 emissions standard, so the diesel supercar is about six years ahead of forthcoming emissions legislation.
The engine features a 60-degree bank angle which, in Audi’s words, “means no free inertial forces or mass moments of inertia can occur with the V12”. Internal dimensions are undersquare (83.0mm bore x 91.4mm stroke), which is not unusual for a diesel, but is unusual for a racing engine.
The block is an alloy of grey cast iron and vermicular graphite, which increases rigidity and fatigue resistance to allow the engineers to build thinner walls and reducing weight.
For the sake of compact design, the V12 TDI engine features the chain-drive layout used by other Audi V-configuration engines to drive the overhead cams. This cam-drive system is placed at the rear of the engine, but unlike other engines, the V12’s chain drives a sprocket, from which the drive is fed by an intermediate gear to the two camshafts. Additional chains drive the oil pump and the common-rail injection’s high-pressure fuel pumps.
These pumps are supplied by Bosch and feed the fuel under high pressure to the piezo injectors, with eight-hole nozzles. On the air side of the equation, twin turbochargers feature variable turbine vane geometry and pump the air through two intercoolers.
In race-going trim, it provided the motive power for the R10 to win at Sebring first time out — running against a field of petrol-engined competitors.
For the past two years, the diesel R10 has won at Le Mans. Depending on the gear set fitted to the transmission, the racing car will reach as high as 330km/h.
The R8 TDI comes with a compact six-speed manual which resides low in the car to help with the centre of gravity. Audi opted for a compact transmission, to allow for the extra length of the V12 engine. From the transmission, the torque is channelled to all four wheels with a front/rear torque split of 40:60.
Two large, transparent roof sections over the cabin distinguish the R8 concept from the standard cars, as does the glazed engine cover.
Inside the concept, Audi has applied aluminium highlights liberally, particularly around the centre console. The additional aluminium trim is unique to the concept.
Visit the Carsales Network again for our news from the North American International Auto Show in Detroit
Comments
Post a Comment