length AUDI A8 2003 D3 / 2.G Technical Features Manual

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Seats
A new seat concept was developed for the
Audi A8 ´03.
The basic seat features the following
standard functions:
– Electric seat length, height and angle
adjustment
– Electric backrest angle adjustment
– Front crash-active head restraints (refer to
Page 21)
The basic seat can additionally be fitted with
– Four-way lumbar support
– Seat memory for driver and front
passenger
– Electrically adjustable head restraints
– Electric belt height adjustersExtra features of sports and comfort seats:
– Electric top 1/3 backrest adjustment
– Electric seat depth adjustment
Optional extras for comfort seat:
– Climate function (refer to Page 85)
– and/or massage function
The massage function is implemented by way
of rhythmic action of the electromechanical
lumbar support, thus massaging and relaxing
the back muscles.
The fixed rear seat bench versions correspond
to those of the front seats, with the third head
restraint being fully retractable. Electric
individual seats are however only available as
"Basic" and "Comfort" versions.
SSP282_116
Crash-active, electronic
head restraint with 70 mm height
adjustment
Thorax/pelvis
side airbag
Backrest fan
Seat cushion fan Electric seat depth adjustment – As the
structure moves forwards it pulls the
padding with it and so extends the seat
area by 50 mm. Backrest adjustment –
The angle of the top
1/3 of the
backrest can be adjusted by 15°
for enhanced shoulder comfort.
Lumbar support with massage
function over a length of 60 mm

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Engine, Mechanics
Variable-intake manifold in 3.7 l engine
Operation of the 3-stage variable-intake
manifold is described in SSP 217.
SSP282_017
This is the same 3-stage variable-intake
manifold as previously fitted in the V8 engine.Due to the piston stroke of only 82.4 mm,
three resonance tube lengths are required to
achieve resonance effects in the lower engine
speed range.
Changeover points:
– Long to short
at 3,280 rpm
– Short to long
at 3,120 rpm
– Short to shorter
at 5,120 rpm
– Shorter to short
at 4,920 rpm
Changeover flap, stage 3
From electronic throttle
Throttle valve
Intake air (inlet)
Changeover flap, stage 2
(open)
Resonance tube, cyl. 5
(inlet end) Vacuum unit
Changeover flap, stage 2 Vacuum unit
Changeover flap, stage 3
Injector
mounts

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Operation
Measurement is performed by way of a
special capacitor which can absorb water
vapour. The water absorbed produces a
change in the electrical properties and thus
the capacitance of the capacitor. The
capacitance measurement thus provides
information on the humidity level. The sender
electronics convert the measured capacitance
into a voltage signal.
Measurement of windscreen temperature
Physical principles
All bodies exchange heat with their
environment in the form of electromagnetic
radiation. This electromagnetic radiation can
include thermal radiation in the infrared
range, visible light or ultraviolet components.
The wavelength of the radiation emitted
depends on the temperature of the actual
body. A change in the temperature of the
body alters, for example, the infrared
component of the radiation emitted. The
temperature of the body can be determined
in a non-contacting manner by measuring the
infrared radiation emitted.
Operation
The infrared radiation emitted by a body
(windscreen) is measured by means of a
highly sensitive infrared radiation sensor.
A change in the temperature of the
windscreen also produces a change in the
infrared component of the thermal radiation
emitted by the windscreen. This is detected
by the sensor and converted by the sensor
electronics into a voltage signal.
SSP282_105
SSP282_106