Audi uses a W12 engine for most of ts variants.
W12 engine configuration (also known as a "WR12") is created by forming two imaginary narrow-angle 15° VR6 engines at an angle of 72°, and the narrow angle of each set of cylinders allows just two overhead camshafts to drive each pair of banks, so just four are needed in total. The advantage of the W12 engine is its compact packaging, allowing Audi to build a 12-cylinder sedan with all-wheel drive
Engine sub-systems
Induction system
The induction system consists of a multipiece intake
manifold.
Exhaust system
To offset production tolerances, the flange connections
between the two primary catalytic converters of exhaust banks 1 and 3and the
intermediate pipe are provided with a length compensation flange. For manufacturing
reasons, the clamp-type flange connection at the primary catalytic converter
(exhaust bank 1/3) is additionally welded after assembly in series production.
The primary catalytic converters are thus paired with the
intermediate pipe. Consequently, replacement of the primary catalytic converters
(exhaust bank 2/4) or intermediate pipe also involves replacing the associated
primary catalytic converter (exhaust bank 1/3).
Double-D pipe Primary catalytic Converter Cylinders 4-6.
The exhaust gas flow from three cylinders is collected in
an exhaust manifold with air gap insulation, thus resulting in a total of four
socalled exhaust banks.
[Originated from the Volkspage]
Edited by Bluenashvillerides.
