Input dataRegulation/control of
Electronic engine management
ME 7.8/Cayman – SDI 3.1/ Cayman S
Engine load
Lambda sensor signals
Engine speed (from crankshaft)
Inlet camshaft phase angle
Knock sensor signals
Vehicle speed
Air-conditioning settings
Accelerator pedal
Temperatures
– Coolant
– Intake air
– Air in engine compartment
– Engine oil
– Ambient air
Pressures
– Engine oil
– Fuel
– Ambient air
Ignition
Manifold injection (Cayman)/
direct fuel injection (Cayman S)
Heating of Lambda sensors
Fuel pump (Cayman)/
fuel pumps controlled on demand
(Cayman S)
Fuel-tank venting
CAN interface with driving dynamics control, transmission control, immobiliser, instrument cluster, climate control,
SPORT button, SPORT PLUS button, sports exhaust system button, diagnostics, etc.
Valve lift switchover
(VarioCam Plus)
Secondary-air injection (Cayman)
Starter
Throttle-valve angle
Idling via throttle valve
and ignition
Fuel pressure (Cayman S)
Throttle valve
Camshaft position
Engine fan
Continuously variable oil pump
Cayman
same conditions, they are
monitored individually by the
knock control. The ignition point
is shifted individually, as and
when necessary, to protect the
cylinders and pistons at high
engine speeds. The on -board
diagnostics, which are compliant
with European standards, ensure
timely detection of any faults
and defects that may occur in the
exhaust and fuel systems and
notif y the driver immediately. This
also prevents increased pollutant
emissions and unnecessary fuel
consumption.Engine cooling system.
Our cross-flow cooling system,
as used in motorsport, supplies
each engine cylinder uniformly
with coolant. Valves are thus
protected against overload and
premature wear, which minimises
the engine’s tendency to knock
and optimises emissions and fuel
consumption.
Engine management system
with E-Gas.
The electronic engine management
system ensures optimum engine
performance at all times. It regu -
lates all engine-related functions
and assemblies (see diagram).
The results: optimum performance
and torque with reduced fuel
consumption and emissions.
Another important function of the
system is cylinder-specific knock
control. Since the six cylinders
never all work under exactly the
Cayman | Drive
4041
Multi - plate clutch 1
Multi - plate clutch 2
Semi -gearbox 2
(2nd, 4th, 6th gear)
Semi -gearbox 1
(1st, 3rd, 5th, 7th, R gear)
Differential
P DK function diagram
is established, and power is
transmit ted to the wheels.
The gear which is engaged is
displayed on the instrument
cluster. Depending on the
gearshif t programme, the gear
change is optimised for comfort
or for sport y handling and takes
place in a mat ter of milliseconds.
The advantages over a fully
manual transmission are very PDK is enhanced by the ‘Launch
Control’ and ‘motorsport- derived
gearshift strategy’ functions (p. 62).
In essence, PDK combines
sportiness with ef ficiency and
comfort. What does all this
mean for you? Exactly what you
would expect: uninterrupted
driving pleasure.
Porsche Doppelkupplung (PDK)
in detail.
The crankshaf t transmits engine
torque to the dual-mass fly wheel
which is then channelled through
the clutch housing and onto the
multi-plate clutches, or to be more
precise, the outer disc carrier.
Under oil pressure, clutch 1 closes
and forms a frictional connection rapid gearshif ts with no
interruption in the flow of power,
which result in a considerably
faster rate of acceleration for the
same rate of fuel consumption.
The advantage over a fully
automatic transmission is the
perceptible increase in driving
dynamics – with a similar level of
comfort, and a distinct reduction
in fuel consumption.
with input shaft 1. The torque is
now transmit ted through the
dif ferential to the rear axle.
At this stage, PDK has already
preselected the next gear.
Engine torque is already acting
on the other outer disc carrier
and, in response to a gear change
signal, the overlap shift is
initiated, i.e. as clutch 1 opens,
clutch 2 closes. The non-positive
connection with input shaf t 2 The compact dimensions of the
gearbox reduce rotational masses
which means that the engine
response is more direct and the
system is more light weight.
This, along with the long-ratio 7th
gear, helps to achieve reduced
fuel consumption and emission
figures comparable with those
of a manual gearbox. With the
optional Sport Chrono Package,
Cayman | Drive
50
46
2
1
R
7 3
5
51
4
6
2
R1
3
7
5
