Service Information
2016 Technik Introduction
Cayman GT4
Porsche AfterSales Training
Student Name: ________________________________________________
Training Center Location: ________________________________________________
Instructor Name: ________________________________________________
Date: ___________________
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Printed in the USA
Part Number - PNA CMN GT4 16
Edition - 7/15
FOREWORD
Foreword
The Cayman GT4 is the motor sports-oriented purist in the Cayman model range,
a vehicle that embodies the essence of the performance capability offered by this
model range.
It transfers the successful GT philosophy of the 911 GT3 models to the Cayman
segment and at the same time adopts their thoroughbred characteristics above all
in the areas of drive, chassis and aerodynamics. It thus becomes a GT vehicle with
mid-engine concept.
The Cayman GT4 therefore offers high race track performance in the GT family.
However, the focus is not exclusively on achieving the fastest lap time, but on
offering a motor sports-oriented, purist and highly-emotional driving experience.
In contrast to the 911 GT3, the Cayman GT4 is not offered with a Porsche
Doppelkupplung (PDK), but is available only with a manual transmission in order
to permit an emotional driving experience with maximum driver integration in
combination with a lower vehicle weight.
The Cayman GT4 is positioned at the top of the Cayman model range with outstanding
driving dynamics and power – it has the following main distinguishing features
compared with the Cayman GTS:
•
Engine with increased displacement and power
•
GT chassis and brake system
•
Downforce-oriented aerodynamics
Note
The Service Information Technik is not intended as a basis for repairs or for diagnosis
of technical problems. Further information for this purpose is available in PIWIS.
Information from the Porsche Academy should also be used.
The information offered by the Porsche Academy is constantly being expanded and
updated - also for other Porsche topics and product lines - to include for example:
•
Access to Service Information Technik presented in the form of web-based
training (WBT)
•
Access to technical highlights
•
Selected technical issues from all subject areas of Porsche vehicle technology
prepared in multimedia format as a technology quiz
•
Access to technical principles
The content of this brochure corresponds to the information status of December 2014.
TOC
1
Engine
1
1.1
General information
1
1.2
Technical data
2
1.3
Crankcase
3
1.4
Crank drive
4
1.5
Cylinder head
6
1.6
Timing drive mechanism
9
1.7
Vacuum pump
10
1.8
Fuel high-pressure pump
10
1.9
Oil supply
11
1.10 Engine cooling
14
2
DME engine electronics
2.1
Overview
15
2.2
Technical data for 3.8-liter DFI engine
16
2.3
Fuel system
16
2.4
Intake system
20
2.5
Mixture formation
22
2.6
Ignition system
23
2.7
Exhaust system, emission control
24
2.8
Thermal management
26
2.9
DME control unit
35
2.10 Power supply
Engine
15
DME engine electronics
37
3
Power transmission
39
3.1
Overview
39
3.2
6-speed manual transmission
40
3.3
Clutch
41
3.4
Shift mechanism
43
3.5
Gear wheel set
43
3.6
Limited-slip differential
45
3.7
Oil supply
45
3.8
Thermal management for the manual transmission
46
3.9
Dynamic transmission mounts
47
Power transmission
95
95
96
96
98
CHAPTER1
1
Engine
1.1
General information
On the Cayman GT4, the increase in displacement and technical innovations that are also
used on the Cayman GTS, such as VarioCam Plus, direct fuel injection (DFI), variable
Engine
resonance intake system or the intelligent thermal management, ensure high performance
as well as high efficiency in combination with low fuel consumption and compliance with
the Federal Emission standard.
The opening angles of the intake valves, the switching strategy of the tuning flaps in
the intake manifold and the engine control were all modified to achieve a harmonious
torque curve.
The mid-mounted flat-six engine is based on the proven 3.4 l engine of the Cayman GTS.
On the Cayman GT4, the displacement was increased to 3.8 liters and the maximum
power increased by 45 hp to 283 kW (385 hp) (Cayman GTS: 340 hp). This maximum
torque is increased by 40 Nm to 420 Nm (Cayman GTS: 380 Nm).
3.8-liter engine of Cayman GT4
1_01_15
1
1.2
Engine
Technical data
Engine type
MA124
Number of cylinders
6
Valves per cylinder
4
Displacement
3,800 cm3
Bore
102 mm
Stroke
77.5 mm
Engine power
283 kW (385 hp)
at engine speed
7,400 rpm
Max. torque
420 Nm
at engine speed
4,750 – 5,800 rpm
Compression ratio
12.5:1
Cut-off speed
7,800 rpm
1
2
1 Torque in Nm
2 Power in kW
3 Engine speed in rpm
3
Cayman GT4 full load curve
2
1_02_15
CHAPTER1
1.3
Crankcase
Like all 9A1 engines, the Cayman GT4 3.8 l flat engine features a two-part, vertically
split crankcase with an integrated crankshaft thrust block.
Engine
Crankcase design
1_03_15
1.3.1 Crankcase ventilation system
Like in all engines, some of the combustion gases are blown past the pistons towards
the crankcase during combustion - these gases are called blow-by gases. If these gases
were not removed, the pressure in the crankcase would increase considerably. A vent
connection is fitted in the crankcase for this reason. For environmental protection reasons,
these gases are not released into the atmosphere but are returned to the engine for
1
combustion via the intake system.
Of course, these positive crankcase ventilation gases contain a proportion of engine
oil and other combustion residues as well as a lot of fuel residues in some cases.
If these gases enter the intake duct, they will contaminate the intake air and can then
impair running smoothness and exhaust emissions and also reduce knock resistance.
These reasons show why effective oil separation is important for the engine.
This task is performed by the oil mist separator, which consists of a pre-separator
and a fine separator. These components form part of the oil module.
1_04_15
1 Removal point for blow-by gases
3
1.4
Crank drive
1.4.1 Crankshaft and mounting
The drop-forged crankshaft runs on eight bearings and has twelve counterweights.
Main bearing 4 is designed as a thrust bearing. Axial play is determined by two thrust
Engine
plates, which are inserted at the left and right of the bearing.
The main bearings are designed as plain bearings with a diameter of 63 mm. Main
bearings 1/3/5/7/8 are smooth bearings, while main bearings 2/4/6 are grooved
bearings. These grooved bearings supply oil through the crankshaft journals to the
lubrication points of the connecting rod bearings. The drive mechanism for the two drive
chains for the camshafts and demand-controlled oil pump is located on the pulley side.
Crankshaft and mounting
1_05_15
1.4.2 Connecting rod
The connecting rods (6) are forged and are split (cracked) at the big end following
machining. Both parts are aligned with one another via the fractured surface. Matching
numbers are provided to ensure process reliability. During fitting, it is important to ensure
that these matching numbers are facing upwards. The connecting rods are 140 mm long.
The piston-pin circlips are secured with twist locks and have an additional hook for removal.
Pistons and connecting rods
1 Plain compression ring
2 Stepped taper-faced ring
3 Oil scraper ring
4 Piston
5 Hook circlip
6 Connecting rod
7 Connecting rod bearing shell
8 Piston pin
4
1_06_15
CHAPTER1
1.4.3 Pistons
The pistons of the Cayman GT4 3.8 liter engine are identical to those of the
991 Carrera S and are made of pressed alloy.
Mixture formation and the direct fuel injection (DFI) combustion process require a special
piston crown shape. The piston crown is a relatively large part of the combustion chamber
Engine
and has a major influence on efficient combustion. Its shape also affects mixture
formation and fresh fuel-air mixture stabilization in the spark plug area during injection
processes in the compression phase in particular.
Piston made of pressed alloy
1_07_15
Piston cooling
The engine of the Cayman GT4 features piston injection cooling to reduce the piston
crown temperature. The spray nozzles are press-fitted in the crankcase. To ensure
the necessary engine oil pressure at the engine bearing points at low rpm and high
engine oil temperatures, these spray nozzles only open at a higher oil pressure.
Oil spray nozzle
1_08_15
5
1.5
Cylinder head
Also in the Cayman GT4 3.8 l engine, the intake ports and valve-seat rings have been
designed for optimized flow and production based on extensive simulations and form
the basis for achieving high specific power and torque values. The intake and exhaust
Engine
camshafts have also been re-adjusted for improved gas exchange. This allows both
high maximum torque and power output values as well as high torque even at low
engine speeds.
1 Exhaust valve
2 Exhaust valve-seat ring
3 Intake valve
4 Intake valve-seat ring
5 Valve guide
6 Valve-spring plate
7 Valve-stem seal
8 Intake valve spring, inner
9 Intake valve spring, outer
10 Valve-spring plate
11 Valve guide
12 Valve-spring plate
13 Valve-stem seal
14 Exhaust valve spring, inner
15 Exhaust valve spring, outer
16 Valve-spring plate
6
Cylinder head and valves
1_09_15
CHAPTER1
1.5.1 Camshaft bearing
The camshafts are installed in the cylinder head by means of individual bearing
saddles in the bearing seat. The camshaft bearings at the chain box are designed as
bearing covers. To avoid confusion, the bearing covers are stamped with the matching
numbers and the letters “E” for intake and “A” for exhaust.
Camshaft mounting
Engine
1_10_15
1.5.2 Cylinder head cover
The cylinder-head cover is a separate die-cast part made of light-alloy. A moulded
elastomer gasket in integrated in the cylinder head cover.
Valve cover and seal
1_11_15
7
1.5.3 Camshafts
Assembled camshafts are used on the Cayman GT4. An assembled camshaft is
a camshaft on which the cams are manufactured separately from the shaft body.
The cams are subsequently joined permanently to the shaft body.
Engine
Comparison of a chilled cast iron and assembled intake camshaft
1_12_15
The separation of the camshaft into cams and shaft allows a choice of material,
production method and heat treatment matched specifically to the functions and
loads.
The technology used in an assembled camshaft offers numerous advantages.
The most important are:
•
Main reason: Improved economy, above all for a modular engine platform with
several cam versions
•
Weight saving compared with a conventional camshaft
•
Transmission of high dynamic and static torques
•
Combination of high-quality cam materials with cost-effective, less highly stressed
tube and end-piece materials
•
Reduced manufacturing effort for further processing and finishing of the camshaft
The exhaust and intake camshafts are each driven directly for each bank by the
crankshaft via a duplex roller-type chain. On the Cayman GT4 3.8-liter engine, the intake
valve lift is 3.6 mm (small) and 11.0 mm (large). The exhaust valve lift is 11.0 mm.
8
CHAPTER1
The timing of the engine is as follows:
Cayman GT4
3.8-liter engine
Intake opens, large lift, late
11° after TDC
Intake closes, large lift, late
59° after TDC
Intake opens, small lift, late
39° after TDC
Intake closes, small lift, late
19° before BDC
Exhaust opens
50° before BDC
Exhaust closes
4° after TDC
1.6
Engine
Timing drive mechanism
The two timing chains are controlled by guide and tensioning rails. Two hydraulic
chain tensioners connected to the engine oil circuit ensure the required tensioning
of both chains. (See arrow)
1
2
1 Upper chain tensioner
2 Lower chain tensioner
Timing drive and chain tensioner
1_13_15
9
1.7
Vacuum pump
Like on the 981 GTS, a mechanical vacuum pump is used on the Cayman GT4 3.8 l
engine to provide the vacuum for the brake booster and various vacuum valves. Its
familiar rotary vane technology as well as its outer position on cylinder head 4-6 and
its drive via the exhaust camshaft were adopted.
Engine
Installation position of vacuum pump
1.8
1_14_15
Fuel high-pressure pump
The fuel high-pressure pump is flanged onto the cylinder head of cylinder bank 1 to 3
and is driven by the exhaust camshaft.
Fuel high-pressure pump
10
1_15_15
CHAPTER1
1.9
Oil supply
The oil supply has the following objectives:
•
Supply of all lubrication points with sufficient engine oil
•
Ensuring the supply of oil even during very high lateral and longitudinal acceleration
•
Reducing friction and drive losses
Engine
Like the 981 and 991 engines, it features:
•
Two oil extraction points per cylinder head
•
One electrically activated demand-controlled oil pump
•
One baffle plate between crankcase and oil pan
Oil circuit
1_16_15
The 3.8 l engine installed in the Cayman GT4 has two oil extraction points per cylinder
head. The Cayman GT4 engine therefore has a total of five oil pumps. These are located
horizontally in the oil pan and are driven by a joint shaft. They are divided into 4 extraction
pumps for the cylinder heads (2 per cylinder head) and a demand-controlled pressure
oil pump.
The oil filter is accessible from below. The oil pressure sensor is fitted on the top
at the oil-filter console.
Oil filter and oil pressure sensor
1_17_15
11
1.9.1 Demand-controlled oil pump
The Cayman GT4 is equipped with an electronic demand-controlled oil pressure pump
in order to reduce the drive losses of auxiliary units and thus increase the efficiency
of the engine with reduced fuel consumption.
Engine
With this electronic demand-controlled oil pressure pump, the delivery rate is pressureand volume-controlled over the entire engine map. In other words, a demand-based oil
pressure is set with a defined oil volume for each engine operating state, e.g. different
engine speeds and loads. The oil pump is integrated compactly in the oil pan area and
is powered directly by the crankshaft via a chain.
Oil extraction pumps and demand-controlled oil pressure pump
1_18_15
Function
Depending on the input variables of engine speed, engine load, engine oil temperature
and the expected change in engine speed, a specific position of the control valve (4)
is defined using a map in the DME control unit. The control valve position regulates
the oil pressure for the spring piston on the gear wheel, which can move in axial
direction. The oil pressure on the control piston is not regulated on the other side.
The control valve is open fully in non-energized state and as a result, the oil pressure
is the same on both sides, which means that the gear wheel will not move.
12
CHAPTER1
This in turn means that the pressure difference between the spring piston and the
control piston can be used to control every position. The teeth are then only partially
engaged as a result of gear wheel displacement. As a result, the delivery rate is adapted
to the demand and the power, friction and energy consumption are reduced.
Engine
1 Drive gear
2 Fixed gear wheel
3 Axially displaceable gear wheel
4 Control valve
A
de-energized
B fully-energized
Demand-controlled oil pressure pump
1_19_15
13
1.10 Engine cooling
The cooling concept is an enhancement based on the effective cylinder head crossflow cooling and was developed to selectively cool the hot spots in the cylinder head
and crankcase.
Engine
Engine cooling ducts
1_20_15
The coolant pump is a separate module which is driven by the belt and is mounted
on the outside of the crankcase on cylinder bank side 1-3. The advantages of this
design are that it permits flexible adaptation of the water pump size and also reduces
repair costs if repair should be necessary.
14
CHAPTER2
2
DME engine electronics
2.1
Overview
A 3.8 l engine is used in the new Cayman GT4. This is based on the 3.4 l mid-mounted
flat-six engine of the Cayman GTS. Technical innovations, which can also be used
DME engine electronics
on the Cayman GTS, make it possible to achieve high performance as well as high
efficiency with low fuel consumption in addition to compliance with emission regulations.
These include, for example, VarioCam Plus, direct fuel injection (Direct Fuel Injection DFI),
variable tuning flaps and intelligent thermal management.
3.8-liter engine of Cayman GT4
2_01_15
15
The power output of the Cayman GT4 is 385 hp (283 kW). The nominal engine speed
is 6,700 rpm and the maximum engine speed 7,800 rpm.
The torque is 420 Nm, and is available over a larger rpm range (4,750 – 6,000 rpm).
DME engine electronics
1
2
1 Torque in Nm
2 Power in kW
3 Engine speed in rpm
3
Cayman GT4 full load curve
2.3
2_02_15
Fuel system
2.3.1 Fuel supply, low-pressure side
The engine has been designed to provide optimum performance and fuel consumption
if premium unleaded fuel 93 octane is used. The engine is suitable for operation with
fuel containing up to 10% ethanol. If unleaded fuels 90 octane are used, the engine’s
knock control automatically adapts the ignition timing.
The use of fuels with octane numbers of less than 90 octane could reduce engine
power and increase fuel consumption. The vehicle must not be driven at full
throttle in this case.
Component overview
2_03_15
1 Fuel tank 14.26 gal, 2.64 gal. reserve
2 Carbon canister, Rest of the World
3 Installation position of the control unit for
the electric fuel pump flow control under
the battery retaining bracket
16
CHAPTER2
Control unit for electric fuel pump
The control unit for electric fuel pump flow control (Figure 2_04_15, 2) is installed
under the battery tray (1). The electric fuel pump is activated by opening the driver’s
door, switching on the ignition, starting the engine and while driving. Depending on
the amount of fuel required, the current consumption and thus the delivery rate of
the electric fuel pump is controlled between 6 and 15 amps via a PWM signal from
DME engine electronics
the DME control unit. The current consumption can be measured at the fuse for
the electric fuel pump.
2
1
1 Battery retaining bracket
2 Current control of electric fuel pump
Control unit for current control of fuel pump
2_04_15
Returnless fuel system
The Cayman GT4 3.8 l engine features a returnless fuel system. On the low-pressure
side, the electric fuel pump installed in the swirl pot delivers the fuel to the 3-piston
high-pressure pump installed on the engine via the fuel filter and fuel pressure
regulator (approx. 72.5 psi/5 bar).
1 Tank filler neck
2 Surge flap
3 Swirl pot with electric fuel pump
4 Fuel filter with fuel pressure regulator
5 Fuel-level sensor
6 Fill-level control valve
7 Control unit for electric fuel pump
8 Electric lines
9 Low-pressure fuel line (approx. 72.5 psi/
5 bar) to the high-pressure pump
10 Engine
11 Tank ventilation to carbon canister
Schematic representation of fuel low-pressure side
2_05_15
17
2.3.2 Fuel supply, high-pressure side
The electric fuel pump in the fuel tank delivers the low-pressure fuel at approx. 72.5 psi
(5 bar) to the quantity control valve (see Figure 2_07_15, 7 and 1) at the high-pressure
pump. The quantity control valve regulates the fuel high pressure by charging the
3-piston high-pressure pump. Driven by the camshaft, the high-pressure pump delivers
DME engine electronics
the fuel at high pressure (approx. 580 to 1740 psi/40 to 120 bar) to the fuel rails (4) on
the left and right cylinder banks and to the injectors (6) via the connecting lines
(Figure 2_06_15, 3) when the engine is running. The fuel high-pressure sensor (5) is
located on the fuel rail.
1
7
Fuel high-pressure pump
2_07_15
1 Fuel high-pressure pump (3 pistons)
2 High-pressure supply line
3 Connecting line (banks 1 and 2)
4 High-pressure rail
5 Fuel high-pressure sensor
6 Multi-hole injectors (with soft clip)
7 Quantity control valve
18
-
Overview of the fuel high pressure side
2_06_15
CHAPTER2
Injectors
Multi-hole fuel injectors are installed for more efficient mixture formation, smoother
engine running and maximum power output. 6-hole injectors are installed on the
Cayman GT4 3.8 l engine.
Use of a softer clip to hold the injector dampens the noise made by the injector when
DME engine electronics
closing.
This is necessary because the modified thermodynamics resulting from the multi-hole
injectors means that the knock detection system reacts very sensitively in the case
of multiple injections in the rev range under 3,000 rpm.
Multi-hole injector
2_08_15
Six-hole injector
2_09_15
Soft clip for injector
2_10_15
19
2.4
Intake system
2.4.1 Air routing
The intake air is routed in twin branches from the air intakes (1) on the left and right
side sections via the air cleaner housing (2) with the air-cleaner elements (3) and the
DME engine electronics
silencers/resonator (4) to the throttle unit (5) for the electronic throttle.
1 Air intake
2_12_15
3 Air cleaner
2_13_15
Overview of intake system
2_11_15
The air-cleaner elements on the left and right (Figure 2_13_15, 3) can be changed
from the rear luggage compartment (Figure 2_14_15, 6).
The maintenance interval for the air-cleaner elements can be found in the countryspecific maintenance schedules in the PIWIS information system.
6 Service cover of air cleaner
20
2_14_15
CHAPTER2
Intake system of Cayman GT4 with tuning flap
The 3.8-liter engine of the Cayman GT4 has a tuning flap for greater volumetric efficiency
and a high engine torque at low to medium rpm as well as an even torque curve.
The tuning flap on the Cayman GT4 is closed by the electro-pneumatic switching
valve between 3,000 and 5,000 rpm by applying a vacuum to the diaphragm cell.
DME engine electronics
1 Throttle housing (electronic throttle)
2 Pressure sensor for detecting the engine
load and intake air temperature
3 Resonance chamber in the intake
distributor
4 Diaphragm cell and tuning flap on air
cleaner
Intake bridge
2_15_15
Pressure sensor for load detection
The engine load and intake air temperature are detected using a pressure sensor
in the intake manifold downstream of the throttle valve (electronic throttle).
Advantages of the pressure sensor for detecting the engine load:
•
Increased power as a result of dethrottling of the intake section
•
Greater precision at low air-flow rates
•
Enhanced resistance to soiling
Tuning flap
2_16_15
2 Pressure sensor for detecting the engine
load and intake air temperature
4 Diaphragm cell and tuning flap on air
cleaner
Pressure sensor
2_17_15
21
2.5
Mixture formation
2.5.1 Mixture adaptations
The mixture adaptations of cylinder banks 1 and 2 for the ranges RKAT (near-idling
range), FRAU (lower load/engine speed range) and FRAO (upper load/engine speed
DME engine electronics
range) have been optimized in a number of details compared with the 3.4-liter engine
in the Cayman GTS.
2.5.2 Injection strategies
Starting (inhomogeneous):
Triple injection during the compression stroke (for emissions reasons when the engine
is cold and to reduce knocking when the engine is warm).
Catalytic converter heating (inhomogeneous):
Twice during the intake stroke and once during the compression stroke (with ignition
point at approx. 18° crank angle after TDC).
Engine warm (homogeneous, only during the intake stroke):
Fuel injection
2_18_15
Idle speed: Single injection
Acceleration under load:
Double injection up to an engine speed of 3,500 rpm
Above this engine speed: Single injection
Variable deceleration fuel cutoff
The variable deceleration fuel cutoff is an enhancement of the conventional deceleration
fuel cutoff. In principle, this involves controlled interruption of the fuel supply in driving
situations where the combustion engine is not required to output any power but is
kept moving by the inertia mass of the vehicle (deceleration, e.g. when driving downhill).
Compared with the usual deceleration fuel cutoff systems, which resume fuel injection
above a predefined engine speed, variable deceleration fuel cutoff systems resume
fuel injection flexibly depending on the driving situation, which may correspond to
an even lower engine speed. Depending on the driving situation, fuel injection can
resume even later, thereby saving fuel.
22
CHAPTER2
2.5.3 Tank ventilation
The fuel tank ventilation system with carbon canister prevents the fuel that evaporates
when the fuel in the tank is heated from getting into the environment. The evaporating
fuel is absorbed by the active carbon in the carbon canister and supplied to the intake
system via the tank vent valve during driving to be burned.
DME engine electronics
USA vehicles feature the NVLD (Natural Vacuum Leak Detection) system for tank
leakage diagnosis.
With this system, tank leakage diagnosis is performed as a passive long-term test
when the vehicle is stationary for an extended period, which means that no short test
is now required for this purpose.
Pneumatic valve
Carbon canister RoW
2_19_15
Carbon canister with tank leakage
diagnosis
2.6
2_20_15
2_21_15
The pneumatic part is installed at the carbon
canister (Figure 2_20_15, 1).
Ignition system
The components and functions of the ignition system such as
•
spark plugs
•
individual ignition coils with integral driver
•
2 knock sensors
correspond to the Cayman GTS:
Ignition coil and spark plug
2_22_15
23
2.6.1 Differential Hall-effect sensor
The differential Hall-effect sensor is installed on the Cayman GT4 like on the 911
Carrera (991) in order to determine the engine speed (Figure 2_24_15). In addition
to detecting the engine speed and reference mark, the multiple Hall-effect sensor
also detects the direction of rotation of the engine. This function enables the engine
DME engine electronics
to start very quickly. The speed sensor, which is installed on the transmission bell
housing, features three integrated Hall-effect sensors (A - B - C). Only one rotor with
60 - 2 teeth is needed on the crankshaft to generate the relevant PWM signal.
•
New differential Hall-effect sensor for measuring the:
- engine speed
- reference mark and
- direction of rotation of the engine
Differential Hall-effect sensor
2_24_15
•
Hall-effect sensor in the sensor
•
1 rotor on the crankshaft
•
PWM signal
•
Temperature-insensitive
•
Suitable for high engine speeds
2.7
Exhaust system, emission control
2.7.1 Exhaust system
The sports exhaust system of the Cayman GT4 3.8-liter engine was dethrottled
by flow optimization measures in order to achieve a lower exhaust backpressure.
It features flow-optimized exhaust manifolds with a close-coupled catalytic converter
arrangement. The left and right silencers are connected by a connecting pipe.
Cayman GT4 exhaust system
24
2_23_15
CHAPTER2
2.7.2 Emission control, catalytic converter, oxygen sensor
The left and right cylinder banks each feature:
•
lambda control with
•
continuous pre-catalytic converter sensor (LSU broadband oxygen sensor)
•
one catalytic converter
•
post-catalytic converter sensor (LSF switching-type oxygen sensor)
DME engine electronics
1 Flow-optimized exhaust manifolds
2 Heat shield
3 Close-coupled 3-way catalytic converter
(ceramic monolith)
4 Catalytic converter mount (with decoupling)
Exhaust manifold
2_25_15
The vehicles comply with the worldwide exhaust emission standards:
EURO 4 (EOBD)
EURO 5 (EOBD)
EURO 6 (EOBD)
1
2
3
USA: LEV II/ULEV (OBD II)
Oxygen sensors and catalytic converter
2_26_15
1 LSU broadband oxygen sensor upstream
of catalytic converter
2 LSF switching-type oxygen sensor
downstream of catalytic converter (LSF)
3 Close-coupled 3-way catalytic converter
(ceramic monolith)
25
2.8
Thermal management
The Cayman GT4 meets the high requirements for vehicle operation under all conditions,
including in hot countries, without restriction. The cooling performance is specifically
designed for this purpose. The cooling system ensures that the engines run in the
appropriate temperature ranges for optimum and permanent high performance.
DME engine electronics
The closed-loop-controlled thermal management system controls the thermal processes
in the vehicle with the aim of achieving optimum efficiency for the overall system and
bringing all components to their optimum operating temperature quickly.
The basic tasks and ranges of the thermal management system are as follows:
•
Reaching the operating temperature quickly
•
Maintaining the prescribed setpoint temperature
As well as controlling the heat distribution between the:
•
Combustion engine
•
Transmission and
•
Passenger compartment
The basic goal is to ensure that all components reach their optimum operating
Map-controlled thermostat
2_27_15
temperature as quickly as possible and to also meet the comfort demands of passengers
by heating up the cabin quickly.
In winter conditions and for cold engine starts in particular, it is important to manage
the small amount of available heat in the best possible way. Effective use of the
available heat helps to save fuel, reduce CO2 emissions and comply with strict
emission regulations. The thermal management system makes it possible to reduce
fuel consumption by accelerating the warm-up phase after a cold start. In addition,
the aim with the standard manual transmission is to reach the optimum operating
temperature as quickly as possible in order to minimise friction losses. If necessary,
the transmission can use the heat of the engine coolant, which is heated up more
quickly, to also reach its operating temperature more quickly. It does this via the heat
exchanger of the cooling system. Conversely, the engine’s additional cooling system
can also help to cool the transmission when it is operating under high loads.
Electro-pneumatic shut-off valve
26
2_28_15
CHAPTER2
2.8.1 Coolant temperature level, engine
The operating temperature is reached quickly thanks to a rotating piston valve that
is actuated by the DME control unit according to a control map. The engine is at
operating temperature when an engine coolant temperature of 221° F (105° C)
is reached.
DME engine electronics
Shut-off valves
The coolant circulation to different components is controlled in the cooling system
by means of the map-controlled thermostat (1) on the one hand and the following
electro-pneumatically actuated shut-off valves on the other.
•
Engine coolant shut-off valve (Figure 2_29_12, 2)
•
Heating heat exchanger
•
Gear wheel oil heat exchanger
Note:
The coolant temperature gauge in the
instrument cluster shows 194° F
at normal operating
.
temperatures (185° F - 221° F)
1 Map-controlled thermostat
2 Coolant shut-off valve on engine
3 Coolant pump
Coolant routing, front side
2_29_15
27
Engine coolant shut-off valve
The engine coolant shut-off valve (electro-pneumatically actuated) is designed as a
rotating piston valve and is used, among other things, to reach the engine operating
temperature faster during the warm-up phase. The coolant circulation is increased
as required by pressurizing the electro-pneumatically actuated coolant shut-off valve
DME engine electronics
via the DME control unit
Closing the engine coolant shut-off valve (vacuum present) largely prevents the coolant
circulating in the engine, even though the impeller of the mechanically driven coolant
pump is turning. This applies as long as the map-controlled thermostat is closed.
The coolant in the engine means that the combustion engine reaches its operating
temperature much faster than in systems without thermal management, however
the coolant pressure also increases along with the engine speed. If the engine coolant
shut-off valve is closed when the thermostat is open, the coolant circulation in the coolant
radiators increases. The engine coolant shut-off valve must open when an engine speed
of 3,000 rpm is exceeded in order to prevent excessively high pressures in the
cooling system.
The engine coolant shut-off valve is kept closed in the following operating modes
Engine shut-off valve
2
2_30_15
Coolant shut-off valve on engine
2.1 Electro-pneumatic switching valve
Switching valve
28
2_31_15
by the DME control unit:
•
Maximum cooling
•
Heating boost mode
CHAPTER2
Shut-off valve for heat exchanger
Coolant flows through this shut-off valve in the event of:
•
Heating request
•
Maximum cooling requests
The shut-off valve for the heating heat exchanger is opened via the air conditioning
DME engine electronics
control unit when the customer requests heat. The engine coolant shut-off valve,
which is closed when the engine is not yet at operating temperature, already makes
enough hot coolant available even after a very short time to heat the passenger
compartment.
When the passenger compartment no longer needs to be heated, the shut-off valve
for the heat exchanger is closed again so that the combustion engine can reach its
operating temperature faster.
The shut-off valve for the heating heat exchanger is also automatically opened when
a request for maximum cooling is sent via a CAN message from the DME control unit
to the air conditioning control unit in order to further reduce the coolant temperature
level in the engine.
Closing the engine coolant shut-off valve below 1,800 rpm increases the flow of
Heater shut-off valve
2_32_15
coolant in the heat exchanger, but also increases the heating output considerably
1
(heating boost mode).
1.1 Electro-pneumatic switching valve
Shut-off valve for heat exchanger
29
Shut-off valve for gear wheel oil heat exchanger
To heat up the gear wheel oil in the transmission faster, the shut-off valve for the gear
wheel heat exchanger is opened (pressurized) during the engine warm-up phase as soon
as the coolant has reached a temperature of 158° F (70° C) and is therefore hotter than
DME engine electronics
the gear wheel oil. The coolant then flowing into the gear wheel oil heat exchanger boosts
heating of the gear wheel oil to the setpoint temperature of 194° F (90° C). The friction
in the gear wheel set is reduced faster (the viscosity characteristics of the oil improve
when the oil temperature increases), shifting comfort is increased and fuel consumption
is reduced.
The shut-off valve is closed by means of vacuum as soon as the setpoint gear wheel
oil temperature of 194° F (90° C) is reached.
The disc valve is opened (aerated) again if the gear wheel oil temperature increases
beyond the setpoint temperature and beyond the temperature of the coolant; the purpose
of this is to cool the gear wheel oil.
1 Electro-pneumatic shut-off valve
2 Shut-off valve for gear wheel oil heat
exchanger
3 Gear wheel oil heat exchanger
2
3
Thermal management for the manual transmission
30
1
2_33_15
CHAPTER2
Map-controlled thermostat
The thermostat is an insertion map-controlled thermostat with a heating element.
The electric heating element of the map-controlled thermostat is energized via the
DME control unit. The flow of current through the heating element (electric resistor)
causes it to heat up, which in turn influences the expansion element in the thermostat
and enables it to be opened. Actuation by the DME control unit is performed by means
DME engine electronics
of pulse width modulation (between 2.5 and 97.5%), which means that the coolant
temperature level can be continuously controlled.
The usual coolant temperature is 221° F (105° C) when the engine of the Cayman GT4
is at operating temperature; it is reduced to 185° F (85° C) during sporty driving and in
Sport/Sport Plus mode by opening (energizing) the thermostat. This supports a
performance-oriented driving style.
The DME control unit can also have the thermostat closed by switching off the
heating current. A precondition for this is a coolant temperature of less than 216° F
(102° C). The map-controlled thermostat starts to open at 216° F (102° C)
+/- 4° F (2° C) when de-energized and is fully open at 239° F (115° C).
The coolant temperature is measured by the engine coolant temperature sensor and
the radiator outlet coolant temperature sensor and transmitted to the DME control unit.
Map-controlled thermostat
2_27_15
Sectional drawing of thermostat
2_34_15
31
Engine coolant temperature sensor
The engine coolant temperature sensor (NTC) is installed at the cylinder head
of cylinder bank 1 near the third cylinder.
The sensor signal is used for:
DME engine electronics
•
DME control (ignition/injection system)
•
Actuating the engine coolant shut-off valve
•
Actuating the map-controlled thermostat
•
Actuating the engine compartment purge fan
•
Checking the oil temperature sensor/oil temperature
•
Air conditioning control
•
Diagnosing the engine coolant shut-off valve
•
Cross-check diagnosis
Diagnosis:
The following temperatures are used for a plausibility test to diagnose the engine
coolant temperature sensor (cross-check diagnosis):
Engine-temperature sensor
2_35_15
•
Engine coolant temperature
•
Engine oil temperature
•
Intake air temperature
•
Ambient temperature
Radiator outlet coolant temperature sensor
The radiator outlet coolant temperature sensor is located in the coolant pipe at the
radiator outlet towards the engine on the vehicle underbody. The temperature information
is transmitted to the DME control unit. The DME control unit uses the plausible signal
to control the thermal management system.
The sensor signal is used for:
•
Activation of the coolant radiator fan (as a function of the coolant setpoint
temperature and coolant temperature)
Radiator outlet temperature sensor
32
2_36_15
•
Function test of the map-controlled thermostat
•
Function test of the engine coolant shut-off valve
•
Diagnosis
CHAPTER2
Electric fans for coolant radiators
The coolant radiators with electric fans (Figures 2_38_15 and 2_37_15, No. 1) are
installed on both sides in the front end of the vehicle. The Cayman GT4 is equipped
with a third central additional radiator on which no electric fan is installed.
The functions of the electric radiator fans are to
•
DME engine electronics
respond to cooling requests from the DME control (reduce engine coolant
temperature, reduce air conditioner refrigerant temperature)
•
provide maximum cooling (emergency operation, n = 2,400 rpm) if there
is no DME information available
•
switch themselves off if there is a risk of damage from overheating.
1 Side radiator
2 Central radiator
3 Heating heat exchanger
4 Disc valve
5 Comfort valve
6 Coolant expansion tank
7 Engine oil heat exchanger
9 Gear wheel oil heat exchanger
10 Engine coolant shut-off valve
11 Map-controlled thermostat
12 Coolant pump
13 Engine coolant temperature sensor
14 Radiator outlet coolant temperature sensor
Cooling system overview
2_37_15
The fan motors are phase-controlled synchronous motors that are steplessly activated
via separate control units (drivers). The fan motors are most efficient at n = 1,800 rpm.
The drivers required for operation of the fan motors receive their commands from
the DME control unit by means of PWM signals and form one unit with the fan motor.
The 12 V power supply for the fan motor is provided via a common line that also
supplies the control unit mounted on it with power.
Coolant radiator and fan
2_38_15
33
2.8.2 Engine compartment purge fan
There are engine compartment purge fans installed on the left and right in the engine
compartment for cooling (Figure 2_39_15 and 2_40_15); these fans blow cool air
into the engine compartment when required. The electrically activated fan motors can
be operated at two speed settings (low and high). There is one relay for each of the
DME engine electronics
two settings. The fan motors are activated by the DME control unit. Activation takes
place as a function of the engine compartment temperature, which is reported to the
DME control unit by an engine compartment temperature sensor installed at the intake
manifold. Another variable is the engine coolant temperature.
Operating condition: With the engine running:
The specified values correspond to an ambient temperature > 50° F (10° C).
Fan setting 1 is activated:
•
“On” when engine compartment temperature > 77° F (25° C)
•
“Off” when engine compartment temperature < 59° F (15° C)
Fan setting 2 is activated:
Purge fan
2_39_15
•
“On” when intake air temperature > 149° F (65° C)
•
“Off” when intake air temperature < 145° F (63° C)
or
•
“On” when engine compartment temperature > 160° F (71° C)
•
“Off” when engine compartment temperature < 153° F (67° C)
or
•
“On” when coolant temperature > 160° F (71° C)
•
“Off” when coolant temperature < 153° F (67° C)
Operating condition: Engine switched off
Installation position of purge fan
2_40_15
If the ignition was switched off at an engine compartment temperature > 113° F
(45° C), the DME control unit enters an “extended motor control unit run-on” mode for
up to 25 minutes. The engine compartment purge fans can be activated as follows
in this case:
Fan stage 1:
•
“On” when engine compartment temperature > 147° F (64 °C)
•
“Off” when engine compartment temperature < 144° F (62° C)
Fan stage 2:
34
•
“On” when engine compartment temperature > 167° F (75° C)
•
“Off” when engine compartment temperature < 147° F (64° C)
CHAPTER2
2.9
DME control unit
The high-performance electronic engine control unit EMS SDI 9.1 from Continental is
installed on the Cayman GT3 3.8 l engine. The DME control unit is installed in a holder
in the rear luggage compartment, mounted on the bulkhead to the engine compartment,
on the right in the direction of travel. The control unit has been specially designed
to meet the requirements for use of direct fuel injection.
DME engine electronics
DME control unit holder
Installation position of DME control unit
2_42_15
2_41_15
The DME control unit Continental SDI 9.1 can be programmed with the data records
for the relevant emission standards, for example EURO 4 (EOBD), EURO 5 (EOBD),
EURO 6 (EOBD), USA: LEV II/ULEV (OBD II), on a country-specific basis.
35
2.9.1 General overview of DME functions
DME engine electronics
Continental SDI 9.1 control unit
2_43_15
•
Thermal management
•
Variable deceleration fuel cutoff
•
Vehicle electrical system recuperation
•
Direct fuel injection (DFI)
•
Low-pressure fuel supply
•
Returnless fuel system
•
High-pressure fuel supply (quantity control valve)
•
Electronic accelerator
•
Electronic throttle with idle speed control
•
VarioCam Plus (intake camshaft)
•
Demand-controlled variable oil pump
•
Tuning flap in intake system
•
Stereo lambda control circuits
•
Static high-voltage distribution (individual ignition coils with integrated drivers),
firing order 1 - 6 - 2 - 4 - 3 - 5
•
Cylinder-specific knock control (with 2 knock sensors)
•
2 electric radiator fans (continuously variable)
•
2 engine compartment purge fans (2 settings: left and right)
•
Differential Hall-effect sensor (detects engine speed, reference mark and direction
of rotation of the engine)
•
Pressure sensor on the intake manifold (detects intake manifold pressure and
intake air temperature)
•
On-board diagnosis for monitoring the emission control system
2.9.2 CAN networking
In addition to the sensors and actuators that are connected directly to the DME
control unit, the DME control unit also has access to other data, which is assigned
to other control units as input or output variables. This external data is accessed via
the internal high-speed network, the so-called CAN (Controller Area Network) bus.
36
CHAPTER2
2.10 Power supply
2.10.1 Fuse carrier
The Cayman GT4 has a fuse carrier on the left and right A-pillars in the footwell
as well as on relay carrier 2 in the rear right of the luggage compartment.
DME engine electronics
The fuse for the electric fuel pump is installed on the fuse carrier in the left footwell
(Figure 2_45_15).
The exact assignment of the fuse carriers and relay carriers and the assignment
of sensors and actuators to the DME control unit can be found in the relevant wiring
diagram on PIWIS Tester II and in the PIWIS information system.
2.10.2 Relay carrier 1
The relay for the electric fuel pump is installed on relay carrier 1 (Figure 2_46_15, 1)),
which is located on the left A-pillar, above the fuse carrier (3).
2.10.3 Relay carrier 2
Most fuses and relays for the DME are located on relay carrier 2 (Figure 2_44_15)
in the rear right of the luggage compartment.
Relay carrier 2
OBD connection
2_45_15
Relay carrier 1
2_46_15
2_44_15
There are various “function overviews” in the
wiring diagram relating to CAN networking
for the area of engine electronics.
37
2.10.4 Vehicle electrical system recuperation
Deceleration fuel cutoff is initiated in conjunction with vehicle electrical system
recuperation if the accelerator is released quickly.
For this purpose, the generator power is increased in a targeted manner by the generator
DME engine electronics
regulator during braking and the recuperated energy is supplied into the starter battery.
The increased generator power acts with a higher braking torque on the crankshaft
of the combustion engine via the belt drive. This leads to vehicle deceleration,
boosting the conventional brake system. The voltage is lowered again during acceleration
and the available energy can be fed into the vehicle electrical system in order to supply
the electrical consumers. This reduces the load on the combustion engine, making
the full drive power available for propulsion. An intelligent algorithm in the energy
management system evaluates various input variables of the components involved,
thereby allowing active coordination of every recuperation operation based on the
battery charge condition and driver request.
38
CHAPTER3
3
Power transmission
3.1
Overview
The transmission is crucial both for driving performance as well as comfort and fuel
consumption. The Cayman GT4 is equipped with a 6-speed manual transmission
Power transmission
as standard. The gear stepping is optimally designed for the engine characteristics
of the Cayman GT4 for good acceleration as well as fuel consumption and comfort
benefits. When driving on highways in particular, low engine speeds reduce the
noise level in the passenger compartment. The gear recommendation in the instrument
cluster helps to ensure optimal fuel economy. In addition, the new gear indicator in
the tachometer shows which gear is engaged. The elevated center console and the
driver’s seat position ensure that there is only a short distance between the steering
wheel and gear lever, creating a sporty driving feeling and guaranteeing fast and
reliable gearshifts.
Cayman GT4 drivetrain
3_01_15
39
3.2
6-speed manual transmission
3.2.1 Technical data
Power transmission
Transmission type
G81/20
No. of gears
6
Spread
3.93
Transmission capacity
420 Nm
Filling capacity
3.2 liters
Weight without dual-mass flywheel and without clutch, with oil
155 lbs (70.5 kg)
Locking value of rear-differential lock for traction/overrun
22/27%
Additional weight for differential lock
4.4 lbs (2 kg)
Transmission ratios
Gear
40
igear
igear
iaxle
Itot.
1
13/43
3.308
3.889
12.863
2
20/39
1.950
3.889
7.583
3
27/38
1.407
3.889
5.473
4
30/34
1.133
3.889
4.407
5
40/38
0.950
3.889
3.694
6
44/37
0.841
3.889
3.270
R
17/39/13
3.333
3.000
11.667
Final-drive ratio
9/35
3.889
CHAPTER3
3.3
Clutch
3.3.1 Clutch plate
The self-adjusting single-plate dry clutch has a clutch plate diameter of 240 mm
(see Fig. 3_02_15).
Pressure plate
Power transmission
3_02_15
3.3.2 Peak Torque Limiter (PTL)
A clutch slave cylinder with peak torque limiter (PTL) is used on the Cayman GT4 for
the first time.
The clutch slave cylinder is connected with the pedal via a piston rod. When the pedal
is pressed, the piston moves in the master cylinder and displaces the brake fluid volume.
This is delivered into the slave cylinder via the clutch line and thus causes the piston
in the slave cylinder to be displaced. This piston acts on the release bearing via a
release lever.
41
In order to reduce the peak torque supplied to the transmission in cases of misuse
(foot slips off clutch pedal), a movable valve disc (Figure 3_12_15, 2) is fitted in the
slave cylinder. This is secured to prevent it from falling out by means of a pressed-in
disc cover (Figure 3_12_15, 1).
When the clutch is engaged, the valve disc moves against the disc cover and thus
Power transmission
reduces the cross-section of the clutch line as well as the clutch engagement speed
(by approx. 20 ms).
When the clutch is disengaged, the valve disc is positioned opposite at the slave
cylinder housing. This allows brake fluid to flow through the bore and past the outside
of the valve disc => there is then no change in cross-section and thus no impediment
for clutch disengagement.
1
2
Slave cylinder with PTL
Detailed view of valve disc
1 Disc cover
2 Valve disc
42
3_12_15
3_13_15
CHAPTER3
3.4
Shift mechanism
The G81/20 is a manual transmission with six forward gears, one reverse gear and
limited-slip differential. Shifting is performed via two cable mechanisms. One cable
is used for selection, the other for shifting. The shifting follows an ‘H’ shift pattern.
Power transmission
Shift mechanism of 6-speed manual transmission
3.5
3_03_15
Gear wheel set
1 Fixed gear wheel, 1st gear
2 Fixed gear wheel, 2nd gear
3 Loose gear wheel, 3rd gear
4 Loose gear wheel, 4th gear
5 Loose gear wheel, 5th gear
6 Loose gear wheel, 6th gear
7 Shifting shaft
8 Input shaft
9 Oil pump drive wheel
10 Oil pump
11 Oil collecting pan
12 Reverse gear
Gear set of G81/20 transmission
3_04_15
The transmission is designed as a two-shaft transmission with one input shaft and
one output shaft.
43
CHAPTER3
3.6
Limited-slip differential
The manual transmission is equipped with a limited-slip differential. The locking value
is 22% (traction) and 27% (deceleration).
Power transmission
1 Crown wheel
2 Differential crown wheels
3 Differential side gears
4 Planetary-gear carrier
5 Vanes
6 Pinion
Limited-slip differential
3.7
3.7.1
3_07_15
Oil supply
Oil types and oil quantities
The transmission is filled with 3.3 liters of Mobilube PTX 75W-90, the change interval
for the transmission oil is 112,000 miles (180,000 km).
45
3.8
Thermal management for the manual transmission
Power transmission
3
2
1 Oil/water heat exchanger
1
2 Temperature sensor
3 Coolant switch-over valve
Thermal management heat exchanger
3_08_15
The transmission oil can be heated up quickly via an oil-water heat exchanger. This lowers
the viscosity of the oil, thereby reducing the friction in the transmission. This has a positive
effect on the fuel consumption.
At higher transmission oil temperatures, the oil can also be cooled via the heat exchanger.
An additional oil pump is mounted on the transmission so that the oil circulates. This pump
is driven via a gear wheel installed on the differential. The supply of cooling oil is therefore
speed-dependent.
Oil pump drive
1 Oil pump drive wheel
2 Oil pump
46
3_09_15
CHAPTER3
3.8.1
Temperature sensor
Power transmission
1 Temperature sensor
Installation position of temperature sensor
3_10_15
The temperature sensor (1) is used to detect the temperature of the transmission oil.
It is a temperature-dependent resistor that is screwed into the transmission from the
outside in the area of the oil pump.
The temperature sensor communicates with the engine control module and
is implemented in the vehicle thermal management system.
3.9
Dynamic transmission mounts
To further improve the driving dynamics as well as the driving and vibration comfort,
the Sport Chrono Package additionally includes dynamic transmission mounts.
The function of the dynamic transmission mounts is identical to that of the dynamic
engine mounts of the 911 Carrera (991). However, as the transmission is installed
at the rear end of the vehicle (as opposed to the engine on the 911 Carrera),
the variable mounts are installed on the transmission.
Dynamic transmission mounts
3_11_15
47
CHAPTER4
4
Chassis
4.1
Overview
The Cayman GT4 features a chassis with wide 20-inch GT4 wheels incl. sports tires
and TPM with racing circuit mode, 30 mm lowering (compared with the Cayman),
Chassis
GT3 front axle, reinforced rear axle and GT3 brake system.
Characteristic features include the chassis that can be adjusted for race track operation,
bearings with ball joints, the Porsche Stability Management (PSM) which can be
switched off completely in 2 stages, helper springs on the rear axle and the
standard assignment of the active transmission mounts.
Phantom illustration of Cayman GT4
4_01_15
The Cayman GT4 has the following product features and modifications:
•
Porsche Torque Vectoring (PTV)
•
20-inch GT4 wheels with sports tires
•
GT3 brake system
•
Lightweight spring strut axle at front
•
Front and rear axles with ball joints
•
PASM with 30 mm lowering and sports tuning
•
Porsche Active Drivetrain Mounts
•
PSM can be switched off completely in 2 stages
•
Adjustable chassis for race track operation
•
Porsche Ceramic Composite Brake (PCCB) optional
The new Cayman GT4 is equipped as standard with Porsche Active Suspension
Management (PASM) incl. 30 mm lowering and specific chassis components.
This allows high agility and driving stability for outstanding driving dynamics and
maximum sports performance.
Individual suspension mounts on the front and rear axles are realized as ball joints
based on the 911 GT3 in order to achieve even more precise wheel guidance.
49
4.2
Front axle
The front axle was adopted largely from the 911 GT3 and offers more precise wheel
guidance as well as higher stability and load capacity through new wheel carriers and
control arms as well as larger wheel bearings.
Chassis
The spacing of the lower control arms corresponds to that on the current 911 GT3.
This means that is possible to adjust the camber and the individual running gear set-up
by means of shims for race track operation.
Front axle
50
4_02_15
CHAPTER4
4.3
Rear axle
The rear axle was also significantly modified. Higher stability is ensured by unique wheel
carriers, reinforcements on the cross-member and control arm as well as an additional
reinforcement strut on the anti-roll bar mount. More precise wheel guidance is offered
by the larger wheel bearings from the 911 GT3.
Modified rear axle
4_03_15
Additional reinforcement strut
for anti-roll bar
Chassis
4_04_15
Additional helper springs on the rear axle are also new. Like on the 911 GT3, these
reduce the weight of the spring system through a shorter main spring and light
additional spring.
The design of the PASM dampers is new for the GT4. The electrical connection for
the internal valving has been relocated to the bottom on both axles.
4.4
Brake system
The reinforced and especially powerful brake system of the new Cayman GT4
corresponds to that of the 911 GT3.
The new Cayman GT4 thus features 6-piston aluminum monobloc fixed calipers
on the front axle and 4-piston aluminum monobloc fixed calipers on the rear axle
(Cayman GTS: 4-piston fixed calipers at front and rear). The large brake discs have
Upside-down damper with helper spring
4_05_15
a diameter of 380 mm on the front and rear axles (Cayman GTS f/r: 330/299 mm).
The brake discs (“friction rings”) are made of grey cast iron and the brake hubs of
aluminum. Compared with conventional brake discs made completely of grey cast iron,
these compound brake discs have a lower unsprung weight.
51
4.
6 Whe
e
l
sa
ndt
i
r
e
s
CHAPTER4
The GT-specific wheel design is based on the current 911 GT3. With its detailed spokes
and open design, it creates a highly dynamic and sportily elegant look. The wheels
are painted in Platinum color (satin gloss) as standard, including wheel hub cover
with “GT4” logo.
These wheels are optionally also available in Black (satin gloss) and with SilverChassis
colored finish (painted).
20-inch GT4 wheels
Front axle
8.5 J X 20 (RO 61)
with sports tires
245/35 ZR 20
Rear axle
11 J X 20 (RO 50)
with sports tires
295/30 ZR 20
Wheel color,
Platinum-colored (satin gloss)
The DOT approved sports tires provide the
necessary grip for the new Cayman GT4.
However, there is increased danger of
aquaplaning on wet roads due to the low
tread depth.
standard
Wheel color, option 1
Black (satin gloss)
Wheel color, option 2
Silver-colored, painted
53
4.7
TPM with racetrack mode
Like the current 911 GT3, the new Cayman GT4 is equipped as standard with Tire
Pressure Monitoring with the additional racetrack mode function.
This system permits precise monitoring of an individually set air pressure taking into
account the specific pressure and temperature characteristics applicable when
Chassis
driving on a race circuit.
The air temperature in the tire - and thus the tire pressure - increases during intensive
driving on a race circuit. Here, an increase in the air temperature in the tire of 122° F
(50° C) and thus an increase in tire pressure of approx. 0.5 bar (7 psi) is not unusual
in this situation. When the tire pressure increases, the tire’s tread becomes deformed
The desired actual tire pressures must not
and contact with the road is reduced. To achieve the best possible road contact surface
be less than 1.8 bar (26 psi) at each wheel
and thus the best traction again, the tire pressure must be reduced.
for racetrack mode.
However, if the tire pressure is reduced by more than 0.4 bar (6 psi) when Racetrack
If the tire pressure falls below minimum
mode is switched off, the red warning message “Tire pressure” will appear on the
pressure, the message “Note min. pressure
screen in the instrument cluster. The tire pressure warning light in the instrument
1.8 bar (26 psi)” appears and the new
cluster stays on even after this message is acknowledged and prevents any further
pressures are not accepted. In this case,
system monitoring of the tire pressures that were set individually for driving on
the required tire pressures must be set again.
the race circuit in this case.
The new tire pressures have only been
To ensure that precise tire pressure monitoring is also still possible when driving on
accepted successfully when the message
race circuits, Racetrack mode allows individual adaptation of the required tire pressure,
“New nominal pressure values” appears
which is predefined in on-road mode. This function is set using the “Tire pressure”
on the multi-function display.
menu on the instrument cluster. When Racetrack mode is activated, a stylized race
circuit with a yellow “R”
is displayed permanently on the screen in the multi-
function display.
When you have finished driving on the race circuit, the tire pressure must be changed
back to the tire pressure required for driving on public roads in order to guarantee
safe driving on public roads. A detailed description of how to activate and deactivate
the TPM Racetrack mode can be found in the Owner’s Manual.
Tire pressure for racetrack mode
54
4_12_15
CHAPTER4
4.8
Control systems
4.8.1 Porsche Stability Management (PSM)
Like the current 911 GT3, the new Cayman GT4 also has a stability management system
with a special sports setup. This allows the Porsche Stability Management (PSM) to
be switched off completely in two stages by the functions ESC OFF and ESC+TC OFF.
Chassis
In the 1st switch-off stage ESC OFF, the system offers increased driving dynamics
on race circuits by deactivating lateral dynamics control (Electronic Stability Control).
This enables the vehicle to be steered around corners with the required drift using
targeted steering movements and/or accelerator pedal control. The sports tuned
longitudinal dynamics control (Traction Control) with high traction through Active
Brake Differential (ABD) and active safety through Anti Slip Regulation (ASR) and Engine
Drag Torque Control (EDTC) remain active in this driving mode.
In the 2nd switch-off stage ESC+TC OFF, the driving dynamics control systems are
deactivated completely. This allows personalized racing-oriented handling on the race
circuit.
PSM function buttons
4_13_15
4.8.2 Porsche Active Suspension Management (PASM)
The new Cayman GT4 is equipped as standard with an adjustable damper system
with 2 maps and a sporty basic setup.
Normal mode
In Normal mode, PASM offers high driving dynamics and agility without neglecting
day-to-day comfort. This setting is suitable for public roads and race circuits with
changing track surfaces (e.g. Nürburgring Nordschleife).
Sport mode
In Sport mode, PASM offers performance-oriented damping with racing sports-oriented
driving dynamics for operation on race tracks with smooth track surfaces.
55
4.9
Porsche Torque Vectoring (PTV)
The new Cayman GT4 also features Porsche Torque Vectoring (PTV) as standard with
a mechanical rear-differential lock and selective braking of the right or left rear wheel.
This system allows high traction on varying road surfaces, increased lateral dynamics,
as well as more precise cornering and improved driving stability.
Chassis
4.10 Dynamic transmission mounts
For further enhanced driving dynamics and comfort, the Sport Chrono Package
additionally includes Porsche Active Drivetrain Mounts (PADM). These adjust their rigidity
and damping depending on the driving situation.
The delayed momentum produced by the mass moment of inertia of the drivetrain when
steering into a corner or during a quick series of alternating bends, for example,
is significantly reduced and any pushing from the rear minimized. Inspired by racing
cars, in which the drivetrain is bolted rigidly to the body, this leads to more stable
and precise handling.
The disadvantages are noticeable engine vibrations and reduced day-to-day usability
for a comfort-orientated driving style. These vibrations can be filtered by means of
softer mounts.
The active transmis combine both of these advantages and at the same time
reduce vertical engine vibration during acceleration at full throttle. The result is more
uniform and higher propulsion force at the rear axle with higher traction and
correspondingly better acceleration.
Transmission mount with PADM
4_14_15
PADM mounts on the transmission
56
4_15_15
CHAPTER4
4.10.1 Function
The active transmission mounts comprise two chambers. The upper chamber is
coupled to the body, while the lower chamber is connected to the drivetrain. Both
chambers are filled with a magneto-rheological fluid and are connected with each
other by an annular gap. An electric coil is located directly next to this annular gap.
A pressure sensor is also fitted.
Mount cross-section (911 version shown) 4_16_15
Change in viscosity
Chassis
4_17_15
Relative motion between the drivetrain and the body forces the fluid through the annular gap.
An electromagnetic field is generated in this annular gap by current flowing through
the coil. This modifies the viscosity of the fluid and the engine mounts are made softer
or harder.
When there is no current flowing through the coil, the fluid has a relatively low viscosity
and the mounts are soft.
When a current is applied to the coil, the powdered iron particles in the magnetorheological fluid are magnetized and join together to create chains. The fluid
becomes viscous, the flow resistance increases and the mounts are hard.
Both drivetrain mounts are controlled separately with switching times of just a few
milliseconds. A large amount of information is processed for control purposes,
including the steering angle, lateral, longitudinal and vertical acceleration as well as
the fluid pressure in the respective transmission mounting.
The system is controlled by the same control unit as Porsche Active Suspension
Management (PASM). It has a highly dynamic control loop and response times of just
a few milliseconds when switching between soft and hard transmission mounts.
A large amount of information is processed, including the steering angle, lateral, longitudinal
and vertical acceleration as well as the fluid pressure in the respective transmission mount.
To ensure excellent driving dynamics and functionality, vehicles with transmission
mounts feature separate and independent control of the right and left transmission
mounts.
The control strategy of the active transmission mounts is also influenced by the PSM
vehicle stability system
57
Overview
The inputs and outputs of the control units as well as the corresponding signals are
shown below.
Chassis
Chassis CAN
Gateway
Lateral acceleration
Longitudinal acceleration
Legend
Vehicle speed
Instrument cluster
Wheel speed FR/FL/RR/RL
Fault indication
Chassis CAN
Sport switch
Display CAN
Clutch switch
PWM signal
Steering angle
Analog signal
Steering angle change time
Engine speed
PADM/PASM control unit
Engine torque
Left mount
Control current
Sensor signal
Accelerator-pedal position
Driver setpoint torque
Transmission status
Right mount
Body acceleration sensor
front right
58
Control current
Sensor signal
CHAPTER5
5
Body
5.1
Overview
The Cayman GT4 is based on the body of the current 981 generation in multi-material
design. In addition to the extensive use of aluminium in order to reduce the vehicle weight,
Body
the local use of ultra-high-strength steel ensures excellent body rigidity and optimum
passenger safety. One of the challenges in developing the body of the Cayman GT4 was
joining the floor pan assembly made largely of aluminium components to the steel
assemblies of the body superstructure.
Thermal joining processes are not possible for this, since they do not permit
production of a joint that offers appropriate static and dynamic strength and also
excludes the possibility of contact corrosion. Joints between aluminum body parts
and steel components must satisfy high requirements with regard to strength and
corrosion protection. If the corrosion protection is defective, joints between aluminum
and steel can be subject to much higher corrosion rates than purely aluminum or steel
joints. For this reason, it is important to ensure in production and in AfterSales that
these joints are produced in accordance with the highest quality standards.
This is ensured by joining the components by non-thermal processes using coated
punched rivets and special screws in combination with adhesive bonding.
The basis for corrosion protection at corrosion-susceptible aluminum/steel joints is
provided by the use of adhesive bonds on the unpainted bodyshell of the Cayman GT4.
These adhesive bonds provide large-area insulation of the aluminum/steel components,
thereby suppressing corrosion processes at the contact point. As a further measure,
all aluminum/steel joints are either sealed with PVC or preserved with wax on a
case-by-case basis after electrophoretic dip priming.
59
5.2
Bodyshell
The bodyshell largely corresponds to that of the 981 basic models. Additional changes
were only required in the following areas:
Body
•
Spring-strut dome reinforcements at rear (riveted and bonded)
•
Tucker studs in the body front section were omitted or arranged offset
•
Additional reinforcements and connection points
The same joining techniques are used. This means that the familiar flow-drill screws,
high-strength blind rivets, MAG welding, resistance spot welding and two-component
structural adhesive are used in the event of repairs.
60
CHAPTER5
Rear end
Structure
The rear end of the Cayman GT4 features special damper mounts, which are reinforced
in order to provide the driving dynamics characteristics of the Cayman GT4.
Body
1
Spring-strut dome reinforcement
Spring-strut dome reinforcement in rear end
5_02_15
5_03_15
1 Spring-strut dome reinforcements
The reinforcement is mounted on the rear end using 2-component structural adhesive
and rivets.
1
2
1 Rear end 981
2 Spring-strut dome reinforcement
Rear end Cayman GT4
5_04_15
Repair
The repair concept for the rear end was adopted from the 981 standard models.
61
5.2.2 Lids
Objective
The front lid, fenders and doors are identical with the standard models. The rear lid is
new and corresponds in its structure and basic form to the lid of the standard models.
Body
Structure
Slots for connection of the rear wing are provided in the outer lid skin. The pneumatic
springs were reinforced in order to support the higher weight of the rear lid due to
the rear wing also when the lid is open. There will not be a rear window wiper for
the GT4 models.
The rear wing is screwed to the lid shell by means of side holes. These holes are
then closed off with plugs.
1
3
1 Lid outer skin
2 Lid shell
3 Slots for rear wing
2
4 Through holes for screw mounting
4
of rear wing
Rear lid on Cayman GT4
62
5_08_15
CHAPTER5
5.2.3 Repair concepts
Objective
Increasingly stringent safety requirements demand that materials with the highest
strength characteristics are used in the Cayman GT4. These ultra-high-strength steels
are used for safety components such as A and B-pillars and door sills.
Body
These materials pose new challenges for body repairs because their extremely high
strength significantly impairs their reshapability, weldability and machinability. In principle,
such repairs correspond to the procedure for purely steel vehicles.
Special precautions must be taken due to the risk of contact corrosion of aluminum
body parts. Grinding dust from the steel parts and particularly sparks produced by
cutting or welding work must not be allowed to come into contact with aluminum
Extreme care must be taken during repair
parts. This also applies to painted aluminum parts.
work in order to prevent contact corrosion.
The paint may be damaged by red-hot steel parts and the steel particles may come
into contact with the aluminum body part, which can lead to contact corrosion on
the undamaged aluminum body. For this reason, the entire body must be protected
when performing steel repairs. This is done by using the required cover tarpaulins
and masking.
Cutting work must be performed only as machining operations with the body saw.
Where grinding work is unavoidable, grinding discs must be used that produce either
no or only minimum sparks.
When performing welding work, a spot welder must be used where possible, since
this produces less weld spatter during the welding process.
Joining techniques
Objective
Both aluminum and steel body parts can be damaged in the event of side or front-end
damage. After removing the damaged parts, the new genuine parts must be fitted in
accordance with the specified repair procedures. Extreme care must be taken when
joining steel and aluminum components in order to prevent subsequent contact
corrosion.
Two-component body adhesive and high-strength rivets or flow-drill screws are used
in the joint areas. This creates an insulating layer between the two materials, as in series
production, and prevents contact corrosion. Always cover and mask the aluminum
parts when welding steel body parts.
Function
An optimum repair quality and the restoration of the entire body structure with all its
functions, such as crash safety, can only be achieved by taking particular care when
carrying out the repair processes. This includes not only the actual repair work to the
damaged areas, but in particular, making sure that the repair areas are prepared
properly.
63
Bonding
Objective
In addition to mechanical joining techniques, such as punch riveted, clinched and flow drill
screw connections, and thermal techniques, such as resistance spot welds, adhesive
Body
bonding using Sikapower 498 and Elastosol M83 is also used in defined areas. However,
these adhesives are dependent on temperature to attain their final strength. Since this is
not an option during servicing, the two-component body adhesive Betamate 2096, which
was also used on the 911, Boxster and Cayman models, is used here. This adhesive
attains its final strength through internal chemical processes.
Function
The body adhesives increase the strength of the connection. Adhesive beads are also
used at other locations on the body for sealing, electrochemical insulation and noise
reduction.
64
CHAPTER5
Riveting
Objective
Rivets are used in all areas on which two-component body adhesive is also used. The
objective is not just to join the components, but to prevent any possible peel stress
at the adhesive bond.
Body
Function
In contrast to the thermal joining techniques, rivets can be used to join the different
materials in the bodyshell of the 981) models. The high-strength blind rivets used for
repairs replace the clinch joints and punch riveting used during production.
Spot welding and MAG welding
Objective
Standard processes used in steel body construction are used to join the sheet steel
body parts, namely resistance spot welding and also, to a limited extent, metal active
gas welding (MAG welding).
Function
Higher-strength and ultra-high-strength components may be replaced only as complete
parts. Partial replacement is not permitted for safety reasons. Here too, any straightening
is only possible to a limited extent, as these components are too rigid and adjacent areas
may be damaged. Resistance spot welding can only be carried out reliably using inverter
welding equipment currently approved by Porsche, as otherwise the strength of the
body may be compromised and result in consequential damage. A visual assessment
of the welding quality is not possible in this instance.
Flow-drill screws
Objective
Different materials can be joined using automated direct screw connections,
even in the case of one-sided access.
Function
A special, coated screw is driven under high contact pressure through a bore in the
outer part to be joined. The inner part is not predrilled during production. Due to the
pressure and the rotational speed, the material is softened, a thread is formed and
the screw is screwed in. During service work, flow-drill screws can be removed and
replaced with new screws. If the thread is damaged, oversize screws are available
(M6 instead of M5). It may be necessary to predrill during repairs.
65
Repair procedures
Objective
One of the challenges during the development of the body and the resultant repair
procedures to be used on the current 981 models was connecting the floorpan
Body
assembly, which is largely made from aluminum components, to the steel groups
of the body. Thermal joining processes are not possible for this, since they do not
permit production of a joint that offers appropriate static and dynamic strength and
also excludes the possibility of contact corrosion.
This is ensured by joining the components by means of the non-thermal processes
described earlier using coated punch rivets and special screws in combination with
adhesive bonding. The basis for corrosion protection at corrosion-susceptible
aluminum/steel joints is provided by the use of adhesive bonds on the unpainted
bodyshell of the Cayman models. These adhesive bonds provide large-area insulation
of the aluminum/steel components, thereby suppressing corrosion processes at the
contact point. As a further measure, all aluminum/steel joints are either sealed with
PVC or preserved with wax on a case-by-case basis after electrophoretic dip priming.
Section repairs
Objective
The objective of the development of section repairs is to reduce the required repair
work. So if a component is damaged, only the areas that are actually affected will be
repaired or replaced. The techniques described earlier can be used here to carry out
appropriate and lasting repairs.
Function
Certain conditions must be met in order to be able to repair damaged areas. For example,
all separating cuts must be performed in accordance with the instructions in the
corresponding Workshop Manual. Body reinforcements can be separated or joined
together only if this is specified in the method descriptions. Otherwise, a damaged
reinforcement must always be replaced with a new one.
Repair specifications
Objective
Because the body is the most safety-critical group in a vehicle, it is essential that
the repair specifications developed by the manufacturer are always adhered to here.
These are designed to ensure that the structure of the vehicle is restored to its original
state after it has been damaged, thereby meeting the required high standards.
66
CHAPTER5
5.2.4 Special tools & workshop equipment
Special tools
The Cayman straightening set (VAS 6756A) or the measuring adapters of the electronic
measuring system are used for body repairs on the Porsche Cayman GT4. This equipment
is set up and used in the same way as existing straightening benches for current
Body
vehicle models. It is manufactured by the familiar companies Car-o-liner and Celette.
Workshop equipment
The workshop equipment primarily comprises a body measuring and straightening
system. Various options are available here. A detailed description of the approved
tools can be found in PIWIS. Only the most important workshop equipment is described
briefly here.
The complete body straightening system package (V.A.G 1920) consists of
straightening bench, straightening device with foot pump and accessory trolley.
Straightening system package V.A.G 1920
5_09_15
Electronic measuring system VAS 6527
5_10_15
The electronic measuring system (VAS 6527) is a further possibility for measuring
and repairing the body.
Illustration
Order number
Purpose
5_09_15
5_10_15
ASE 40645100000
ASE 40645600000
Body repairs
Body repairs
67
CHAPTER6
6
Body – Exterior equipment
6.1
Overview
The core features of the new Cayman GT4 are exceptional performance and emotional
driving pleasure. This is made possible by means of a powerful engine, a manual 6-
Body –
Exterior equipment
speed transmission, racetrack-tested chassis components including large brake
system, motor sports-oriented aerodynamics and a distinctive design.
Cayman GT4
6_01_15
69
6.2
Design
Objective
The exterior of the Cayman GT4 is characterized by specific components such as the
Body –
Exterior equipment
front apron with additional air outlet opening in front of the luggage compartment lid
and air intake grilles as well as a large front spoiler, black Bi-Xenon headlights and
SportDesign exterior mirrors.
Exterior modifications on Cayman GT4 compared
6_02_15
with Cayman
Other unique features include the sideblades in front of the side air intakes with embossed
“GT4” logo, the rear apron with diffusor look and the black tail lights. The fixed GT4
rear wing including aluminum wing supports and the rear spoiler located underneath
with integrated Gurney flap are other particularly distinctive features.
6.2.1 Front view
The distinctive front design of the new Cayman GT4 is characterized by its unique
front apron.
Front view of Cayman GT4
6_03_15
This does not just lend the new Cayman GT4 a differentiated look, but also performs
functional tasks by providing high cooling performance for the powerful 3.8 l flat
engine, aerodynamic downforce on the front axle as well as protecting the radiator
against damage. The differentiated look is rounded off by black Bi-Xenon headlights
and darkened front light modules.
70
CHAPTER6
Front apron
Structure
The front apron features large air intakes and specific additional elements such as the
air intake grilles, the air outlet in front of the front luggage compartment lid as well as
the large and low-positioned front spoiler lip. The auxiliary headlights are connected
Body –
Exterior equipment
to the vehicle wiring harness by a separate wiring harness in each case.
Repair
The installation concept for the front apron corresponds to that of the 981 Cayman
standard models. It is mounted here also by means of screw connections and side
retaining strips.
1
4
5
1 Front apron
2 Center air intake
3 Side air intake
3
4 Air outlet
2
Outside structure of front apron
6_04_15
1
2
5 Side spoiler
3
1 Front apron
2 Wiring harness
3 Towing device
Inside structure of front apron
6_05_15
71
Center air intake
4
Body –
Exterior equipment
3
2
1 Retaining clips
2 Rear center retaining frame
3 Air intake grille
4 Front center retaining frame
1
Centre air intake
6_06_15
Structure
The center air intake consists of several parts and comprises the front center retaining
frame, the air intake grille, the rear center retaining frame and the retaining clips.
The front apron is installed in position using these retaining clips.
The radiator for the engine coolant is mounted behind the center air intake.
Repair
The repair concept provides for replacement of all individual components of the center
air intake.
72
CHAPTER6
Side air intake
Structure
The auxiliary headlights are integrated in the side air intakes. They are screwed onto
the retaining frame by means of three screw points and additional reinforcement.
The side air intake is also provided with a grille in order to protect the air conditioning
Body –
Exterior equipment
condensers against damage. The rear retaining frame is clipped together with the
front frame and the grille is mounted in between. The side air intakes are fastened
to the front apron by means of screw connections.
The air conditioning condensers are installed behind the side air intakes.
1
2
3
1 Retaining frame, side front
2 Screw points for auxiliary headlight
3 Reinforcement
4
4 Retaining frame, side rear
5 Air intake grille
5
Left air intake
6_07_15
Repair
The repair concept provides for replacement of the individual retaining frames
(front and rear), the auxiliary headlights, reinforcements and grille.
73
Air outlet grille
Structure
The front air outlet is new on the Cayman GT4. The integrated grille is attached to
the front apron by means of a retaining frame and retaining strip. The retaining strip
Body –
Exterior equipment
is permanently connected to the front apron. The retaining frame with grille is then
clipped onto the retaining strip and screwed into position.
5
4
3
2
1 Screws for retaining frame
2 Retaining frame
3 Air outlet grille
1
4 Retaining strip
5 Adhesive tape
Air outlet GT4
6_08_15
Function
An exhaust air duct is installed between the radiator and air outlet grille in order
to ensure a sufficient air throughput for the centre radiator.
Exhaust air duct
6_10_15
2
1
1 Radiator
2 Exhaust air duct
Exhaust air duct
74
6_09_15
CHAPTER6
Repair
The repair concept of the air intake grille provides for replacement of all components
except for the retaining strip. This is permanently bonded with the front apron and
cannot be replaced individually. If this component is damaged, it is necessary to replace
Body –
Exterior equipment
the complete front apron.
Spoiler
Structure
The front apron does not just feature the front spoiler lip, but also spoilers fitted at
the sides. The front spoiler lip is clipped into the front apron and secured by means
of two screws on the left and right. The side spoilers are bonded onto the front apron
and clipped into place.
1
2
3
1 Front apron
4
2 Adhesive film
3 Side spoiler
4 Front spoiler lip
Front spoiler lip on Cayman GT4
6_11_15
1
Function
The spoilers of the front apron and the rear spoiler together form a perfectly
matched aerodynamic package.
Repair
As familiar from other GT models, the front spoiler lip is supplied loose with the vehicle
when the vehicle is delivered. It can be simply clipped into place and secured to the
2
front apron by means of expanding rivets. The side spoilers are adhesively bonded
onto the front apron. They can be repaired individually in the event of repair and fitted
again using the adhesive film.
Connection of side spoilers
3
6_12_15
1 Front apron
2 Adhesive film
3 Side spoiler
75
Headlight cleaning system
Structure
A headlight cleaning system is optionally available for the Cayman GT4. The is realized
Body –
Exterior equipment
by means of a telescopic nozzle secured in a retaining plate that is bonded onto the
front apron.
1
2
3
1 Front apron
2 Retaining plate
3 Telescopic nozzle
Headlight cleaning system on Cayman GT4
6_13_15
The tube for the headlight cleaning system is secured on the inside of the front apron
by means of retaining clips. The disconnection point to the vehicle is located on the
left side of the front apron.
1
2
1 Front apron
2 Disconnection point
3 Tubing
4 Retaining clips
3
4
Tubing for headlight cleaning system.
6_14_15
Function
The telescopic nozzle is clipped into the retaining plate. The actual function of the
headlight cleaning system is the same as on the Cayman standard models.
Repair
The repair concept provides for replacement of the telescopic nozzle, tubing and
retaining plate. The retaining plate is bonded into the front apron for this purpose.
76
CHAPTER6
6.2.2 Side view
In the side view , the particularly low vehicle position (-30 mm compared with Cayman),
the large and distinctive 20-inch GT4 wheels and the filled out wheel housings define
the extremely sporty character of the new Cayman GT4. Other distinctive elements
are the GT4 sideblades in front of the side air intakes to improve engine air intake,
Body –
Exterior equipment
the SportDesign exterior mirrors with V- shaped mirror base as well as the characteristic
rear wing with light and uniquely shaped wing supports.
Side view of Cayman GT4
6_15_15
Side skirts
Structure
The side skirts have the same design as on the Cayman standard models. The installation
concept is realized by means of clips and screw connections on retaining strips and
the bodyshell.
Function
The air intakes of the side skirts supply the engine with fresh air and are also used
for thermal management. The sideblades on the air intakes are a special feature
of the Cayman GT4.
Repair
As a result of the sideblades attached to the side skirts, separate side skirts are offered
as a spare part for the Cayman GT4. These have through holes for mounting.
77
Air intake trim (sideblades)
Structure
The sideblades are painted in the vehicle color. The “GT4” logo is additionally embossed
on them. They are fixed on the side skirt by means of adhesive tape and are additionally
Body –
Exterior equipment
secured by screws.
2
1
1 Side skirt
2 Sideblade
Side skirt on Cayman GT4
1
6_16_15
Function
The sideblades at the rear are intakes of the side skirts serve the purpose of more
targeted routing of the intake and cooling air.
2
Repair
The sideblades can be replaced individually due to the installation concept with
adhesive tape and screws. The through holes of the sideblade screw connection
in the side skirt ensure exact positioning.
Sideblade mounting
1 Screw points
2 Adhesive bond
78
6_17_15
CHAPTER6
Exterior mirrors
The Cayman GT4 is equipped as standard with the SportDesign exterior mirrors familiar
from the 991 Turbo S with additional adapter ring (base adapter) for mounting on the door
outer skin.
Body –
Exterior equipment
Structure
These exterior mirrors have a V-shaped mirror base and a modified mirror housing.
The exterior mirror consist of 3 parts and the mirror housing is made of plastic
(polycarbonate). With SportDesign exterior mirrors, the mirror base consists of one piece.
SportDesign exterior mirror
6_18_15
SportDesign exterior mirror
6_19_15
Function
The SportDesign mirrors cannot be folded in electrically. They feature automatically
darkening mirror glasses and a memory function.
Repair
It is possible to replace the base adapter and seal for connection to the door outer
skin, mirror housing parts, mirror glass, mirror base and the internal mechanism.
79
6.2.3 Rear view
In the rear view , the differentiating features of the new Cayman GT4 include a rear
apron with unique bottom elements in diffusor look, darkened tail lights and a sports
exhaust system with two central tailpipes.
Body –
Exterior equipment
The new Cayman GT4 documents its outstandingly sporty character and demonstrates
its inherent suitability for the race track through its distinctive vehicle design with low
vehicle center of gravity and its downforce-oriented aerodynamics.
Rear view of Cayman GT4
80
6_20_15
CHAPTER6
Rear apron
Structure
The basic form of the rear apron was adopted from the 981 Cayman GTS models.
A new feature is the rear diffusor, which was adapted to the aerodynamic requirements
Body –
Exterior equipment
of the GT4.
4
3
1
2
1 Rear apron
5
2 Rear spoiler plate
3 Adapter
4 Upper part of spoiler
5 Rear diffusor
6 Tailpipe cover
6
Rear apron on Cayman GT4
6_21_15
In addition to the rear diffusor, the rear apron also includes the adapter for the rear
spoiler and the tailpipe cover. The rear diffusor and tailpipe cover have a Black
grained finish.
Repair
The installation concept for the rear apron corresponds to that of the Cayman
standard models. The rear diffusor, tailpipe cover and spoiler can be replaced
separately.
81
Rear spoiler
The large, fixed GT4 rear wing with integrated side plates is dominant and highly
efficient. It is connected with the rear lid by means of two wing supports made
of aluminum. Together with the rear spoiler located underneath with integrated
Body –
Exterior equipment
separation edge – the so-called gurney flap – this combination produces an air flow
with aerodynamic downforce for high driving stability and exceptional cornering
performance.
Structure
The spoiler mounted on the rear apron is screwed to the adapter, which is mounted
on the base plate. The spoiler drive of the 981 Cayman was used for connection,
but without the drive motor. The spoiler is mounted on the adapter by means of four
screws and guide flanges. The adapter is in turn connected to the base plate by
screw points.
2
3
1
Flanges
6_23_15
Spoiler on rear apron
6_22_15
Repair
When installing the spoiler, attention must be paid to correct positioning of the adapter.
Grooves and screw connection
6_24_15
Together with the fitted spoiler, the latter creates the final gap appearance. Spoiler
positioning is then possible by means of the flanges and grooves. When assembling
the spoiler on the adapter, the screws are fitted in a sequence specified in the
Workshop Manual.
82
CHAPTER6
Rear wing
Structure
The rear wing consists of several parts. These are the wing itself, which is made of
carbon, the end plates made of polyurethane and the wing supports made of aluminum.
Body –
Exterior equipment
The wing supports are designed in Black or Silver. The rear wing is mounted by means
of the wing supports, which are screwed to the rear lid through slots in the lid.
2
1
3
5
4
Wing support
6_25_15
1 Wing support
2 Wing support retaining plate to wing
3 Seal
Rear wing on Cayman GT4
6_26_15
Repair
4 Screws
5 Rear lid
The wing supports, the retaining plates for connection of the wing supports to the
rear wing, the rear wing and the wing end plates can be replaced for repair. When
fitting the wing supports, the tightening sequence described in the Workshop Manual
3
1
must be observed. The bonded-on seal between the wing support and rear lid is available
separately for repair. The wing end plates are another special feature. These are
adhesively bonded together with the rear wing. When carrying out a repair, they are
fitted on the rear wing using a pressure roller.
2
Wing mounting
6_27_15
1 Rear wing
2 Wing support
3 Retaining plate
83
CHAPTER7
7
Body – Interior equipment
7.1
Overview
Characteristic features of the new Cayman GT4 include its Black interior with
Platinum-colored decorative seams (optionally in Yellow or Red), elements in
Body –
Interior equipment
Alcantara, door panels with opener loop, trim strips made of brushed aluminum,
specific “GT4” model logos and the new GT4 sports steering wheel with 360 mm
steering wheel diameter (Cayman GTS: 370 mm).
Interior of Cayman GT4
7_01_15
Material concept
The sporty material concept is used with Alcantara on the steering wheel rim, shift lever,
seat centres, door closing handles, armrests of the door panels, storage compartment
lid of the center console and rooflining including A-pillars.
Displays
The differentiating features of the new Cayman GT4 also include an instrument
cluster with yellow needles and figures as well as a titanium-colored tachometer
(similar to the 911 GT3).
85
Seats
The new Cayman GT4 is equipped as standard with the 2-way sports seat Plus with
seat center made of Alcantara and raised side bolsters made of leather. The “GT4”
logo is embroidered on the headrests. The adaptive sports seat Plus with 18-way
Body –
Interior equipment
adjustment and a 918 full bucket seat made of carbon-fiber-reinforced plastic (CFRP)
are also optionally available.
Individual options
For particularly sporty use, the new Cayman GT4 can be optionally equipped with
a Clubsport package as well as the Sport Chrono package with analog stopwatch
in the instrument panel, Porsche Track Precision App and lap trigger preparation.
Deletion of the manual air conditioning system and the CDR radio system is also
offered for reduction of the vehicle weight.
Further personalization options are offered by an extensive range of individual options,
including leather interior, trim strips in anthracite-colored aluminum, red or yellow
decorative seams as well as additional elements in leather, Alcantara, carbon and
stainless steel.
86
CHAPTER7
7.2
Trim and linings
Objective
Due to the sporty vehicle concept and the additional personalization variants, a number
of the interior components of the Cayman GT4 were modified in comparison with the
standard models.
Body –
Interior equipment
1
4
5
3
2
8
6
1 Carpet floorpan
2 Rooflining
7
3 Rear panel trim
4 Engine compartment lining
5 Luggage securing bar
6 Belt collar
7 Side engine compartment lining
8 Luggage compartment trim
Interior changes on GT4
7_02_15
GT4-specific components
Cayman S components
The door entry guard and badge on the shift lever were additionally provided with
the “GT4” logo.
87
Door panel
Structure
The door panel of the Cayman GT4 largely corresponds to that of the Cayman S models,
Body –
Interior equipment
but the Cayman GT4 has a pull loop instead of the door opener. In addition, the armrest
on the door panel is covered with Alcantara.
1
2
1 Door panel
3
2 Pull loop
3 Armrest
Door panel on Cayman GT4
7_03_15
Repair
The door panel is assembled/disassembled like on the Cayman standard models.
88
CHAPTER7
Seats
3 different seat versions are available for the Cayman GT4. All versions feature a GT4
logo in the headrest and an Alcantara strip in the center cushion. The side bolsters
are also upholstered to increase lateral support.
Body –
Interior equipment
1
3
2
1 Sports seat Plus, 2-way
2 Full bucket seat 918
3 Sports seat Plus, 18-way
Seat range for Cayman GT4
7_04_15
89
CHAPTER8
8
Heating and air conditioning
8.1
Overview
The Cayman GT4 is equipped with a manual air conditioning system (1-zone) as
standard. However, the Cayman GT4 can also be optionally equipped with automatic
Heating and air conditioning
climate control (2-zone). This system allows separate adjustment for the driver and
passenger of the
•
temperature and the
•
air quantity at the passenger vents in the dashboard.
The air distribution is the same for both zones.
The Cayman GT4 can also optionally be ordered without air conditioning system.
Center console with air conditioning control panel and air outlet vents
8.2
8_01_15
Operation
The operating and air-conditioning unit in the center console permits adjustment of the
air-conditioning functions and other operating functions. The control unit integrated in
the operating unit also regulates and controls all the heating and air conditioning system
components required for passenger compartment air conditioning, such as activation
of servo motors or of the air-conditioning compressor.
91
8.2.1 Air conditioning system (manual)
With the standard air conditioning system (1-zone), the air flow, air distribution and
temperature can be manually adjusted. The settings and adjustments for temperature
and air flow are shown by means of a segment display on the operating unit display.
Heating and air conditioning
The air distribution setting is communicated by means of LEDs in the buttons on the
operating unit.
Control panel of manual air conditioning system (standard)
8_02_15
8.2.2 Automatic climate control (2 zones)
The automatic climate control system allows different temperatures to be selected
for the driver and passenger. The temperature settings are shown on the operating
unit display. With this system, the air flow and air distribution are set and controlled
uniformly on both sides. Individual adjustment of the desired air flow is possible by
individually adjusting or closing the air vents (center/side) on the dashboard.
Control panel of 2-zone automatic climate control (option)
92
8_03_15
CHAPTER8
Setting air conditioning
The air flow can be adjusted individually on Cayman GT4 vehicles with 2-zone automatic
climate control. For this purpose, “Air conditioning” must be selected and confirmed
under “Settings” in the “Vehicle” main menu in the instrument cluster. Then select
“Air flow” and confirm. Three different settings:
•
Soft
•
Normal
•
Strong
Heating and air conditioning
are then offered and can be selected here.
8.2.3 Deletion of air conditioning system
Based on the concept of the GT vehicles (lightweight construction), it is possible
to order the Cayman GT4 with the option “Deletion of air conditioning system”.
In this case, the operating unit of the manual air conditioning system is installed
without the A/C function buttons.
Control panel “Deletion of air conditioning system” (option)
8.3
8_04_15
Seat heating
Heated seats are optionally available for the Cayman GT4 in combination with the 2way sports seat Plus and 18-way sports seat Plus. The option is not available for the
full bucket seat 918.
93
CHAPTER9
9
Electrics and electronics
9.1
Exterior lighting
Headlights
Electrics and electronics
The headlights contain the direction indicator, dipped beam and high beam functions.
The new Cayman GT4 is equipped as standard with Bi-Xenon headlights with automatic
driving light control (AFS) and halogen auxiliary headlights.
The Cayman GT4 can also be optionally ordered with black Bi-Xenon headlights with PDLS.
Automatic driving light assistant
When the automatic headlights function (automatic driving light assistant) is activated,
this function switches between daytime running lights and dipped beam, depending on
the ambient brightness.
Front view of Cayman GT4
9_01_15
Position lights
Darkened LED position lights with integrated daytime running lights are installed
below the headlights in the air intakes.
Tail lights
Only LEDs with tail light, brake light and direction indicator functions (direction indicators,
hazard warning lights) are used in the darkened rear light modules. The reflectors were
integrated into the tail light units.
Rear view of Cayman GT4
9_02_15
95
9.2
Instrument cluster
The instrument cluster was enhanced based on the current 9x1 generation and
the familiar 911 GT3-specific appearance.
Design
The instrument cluster is differentiated by its black instrument dials with yellow pointers
Electrics and electronics
and increment markings. The dial of the tachometer is titanium-colored with GT4 logo.
The red rpm range, which only starts above 7,800 rpm, is a particular characteristic
feature of the instrument cluster.
As on the current 9x1 Carrera models, the 4.6-inch, high-resolution color screen on
the instrument cluster offers comprehensive display options. The information Vehicle,
Audio, Trip, Tire pressure including Circular path (Racetrack function), as well as the
options Navigation, Map, Phone and Sport Chrono, can also be displayed here. The new
Cayman GT4 is equipped as standard with the G-Force display.
Instrument cluster
9_03_15
9.3
Infotainment systems
9.3.1 Audio systems
As standard, the new Cayman GT4 features the CDR audio system with a 7-inch color
display and touchscreen as well as 4 loudspeakers with a total output of 2 x 25 W.
Various audio options are offered for personalization. These include:
•
Sound Package Plus with 9 loudspeakers and a total output of 235 W
•
CDR Plus audio system with digital double tuner
•
Porsche Communication Management (PCM) incl. navigation module
The digital satellite radio SDARS from the provider XM is additionally available
for the USA and Canada markets.
It is additionally possible to reduce the vehicle weight by omitting the CDR audio
system. Instead of the audio system, the customer receives a two-part storage
compartment when this option is selected.
96
CHAPTER9
9.3.2 PCM
The PCM also features a performance display in combination with the optional
Porsche Communication Management.
Other audio options include:
•
Digital radio
•
Online services
•
Mobile phone preparation
•
Telephone module
•
Voice control
•
6-disc CD/DVD autochanger
Electrics and electronics
Personal online services
The prerequisites for this function are identical to those of Internet radio services.
Google Search
Following successful connection of a smartphone to the PCM, Google Search is available
in the navigation area under the “POI” menu item along with the familiar POI search.
Weather information
Following successful connection of the smartphone to the PCM, the weather information
is available in the INFO main menu. Depending on the scope of equipment in the PCM,
the function is either in the INFO main menu or under the “Online weather” menu item
under INFO –> OPTION.
Traffic sign display
The traffic sign display is also extended in the PCM in combination with the optional
camera system. Up to now, speed limits that were stored in the navigation database
were displayed. Using the camera system, up to three traffic signs with additional sign
can be displayed at once. In addition to the speed limits, restrictions on overtaking as
well as lifting of the restrictions can also be displayed.
Function
The traffic signs detected by the camera and the information available in the database
are compared with each other.
The PCM serves as a data supplier for the information from the digital map. This is
compared with the information derived from image recording in the camera control
unit and displayed on the instrument cluster and the PCM. This increases reliability.
97
9.4
Sport Chrono package
As on the 911 GT3 as from MY 2015, the Sport Chrono package including Porsche
Track Precision App is also optionally available for the Cayman GT4. The package
includes the lap trigger preparation, which is not just used for the Porsche Track
Precision App, but is also required for the infrared lap trigger optionally available
Electrics and electronics
through Tequipment.
9.4.1 Lap trigger system
The lap trigger system allows precise recording of lap times. Depending on the system
configuration, the lap times can be recorded by means of
•
the steering column switch
or automatically via
•
the Porsche Track Precision App using GPS
•
an additionally available infrared lap trigger with external transmitter.
The following options are available
•
Lap trigger preparation (I 643)
•
Porsche Track Precision App
•
Lap trigger (Tequipment)
Overview of time recording
via lap trigger
Stopwatch timing display
The stopwatch timing is displayed:
• In the stopwatch on the dashboard
via GPS
• In the Chrono menu on the multi-function display
• In the optional PCM in the CAR main menu
via steering column switch
A
B
C
D
Number of timed laps
Current stop time
Reference time, fastest lap
Circle display: Comparison of current
lap time with the reference time
STARTING timing
1 “Chrono” main menu
2 Select “Start”
and confirm
Graphic representation of time recording
98
9_04_15
CHAPTER9
The time is displayed on the
•
Sport Chrono clock
•
the instrument cluster as well as the
•
optionally available PCM
In conjunction with PCM, the Sport Chrono package functionality is extended by display,
storage and evaluation of measured lap times as well as the performance display.
Electrics and electronics
Infrared
WLAN
System overview
CAN bus
Component overview for lap trigger option
Lap trigger preparation
9_05_15
Red frame
Lap trigger preparation
Green frame
Porsche Track
The scope of the preparation (Figure 9_05_15) includes a WLAN interface and
the preparation for the lap trigger connection. The WLAN interface is integrated
iPrecision App
Yellow frame
Infrared lap trigger
in the wiring harness of the gateway control unit. This ensures the functionality
of the Porsche Track Precision App.
99
Porsche Track Precision App
Using the Porsche Track Precision App (Figure 9_05_15, green frame), it is possible
to automatically record lap times via GPS, for example, and to record the following
driving data
Electrics and electronics
•
Vehicle speed
•
Steering angle
•
Braking and acceleration behaviour
•
Engine speed
•
Lateral acceleration
on a smartphone. This data can then be shared and compared with other drivers.
When driving on a race circuit, the driving dynamics are visualized on the smartphone,
and the lap time differences compared with a reference lap are displayed in addition
to sector and lap times. The app makes use of highly precise vehicle data, which is
provided via the WLAN interface.
Operating instructions and FAQ
The settings menu (Figure 9_07_15) can be opened by means of “Set” (Figure 9_06_15).
For safety reasons, the smartphone should
The operating instructions (Figure 9_08_15) can then be accessed via the “Help?” or
be mounted in the holder provided.
“?” button. There is an “FAQ” button at the top right (Figure 9_08_15) in the operating
instructions screen. This allows a connection to the internet to be established in order
to view frequently asked questions and answers.
Settings
Lock Reference Lap
Start-up
Extended Views
Language
English
Establishing a WLAN connection
GPS settings
Scale Ghost
Connecting an external GPS receiver
Views when driving
Use with Sport Chrono and lap trigger
Start screen
9_06_15
Settings screen
9_07_15 Operating instructions screen
9_08_15
Main functions
The Porsche Track Precision App has four main functions, which can be displayed
and operated on a smartphone:
100
•
Live display
•
Analysis functions
•
Evaluation and statistics functions
•
Profile/data management and exchange
CHAPTER9
Live displays
The live display offers clear and easily readable displays that allow the driver
to directly determine and improve his driving performance while racing.
Automatic triggering of laps and sectors takes place via GPS or, with even
greater precision, using the optional lap trigger.
Electrics and electronics
The live displays include the following:
•
Display and recording of lap and sector times (lap timer) and their real-time
deviation from the defined reference lap as well as visualization of the driving
dynamics - G-force, traction and driving stability
•
Clear representation of the difference compared with a reference lap –
ghost car – according to time, distance and speed
Live display of timing, G-force, traction, driving stability
9_09_15
Live display of ghost car showing time, speed and distance differences
9_10_15
101
Analysis functions
Video analysis of driving performance is possible on the smartphone immediately after
the vehicle is stopped. This makes it possible to improve on this performance already
in the next lap.
The analysis functions include video recording with animated representations of the
Electrics and electronics
achieved driving performance data
•
Engine speed, gear and vehicle speed
•
Steering angle and steering behaviour
•
Accelerator and brake pedal position
•
G-force
•
Traction
•
Oversteer/understeer
•
Display of recording information
•
Deviation from a selected reference
•
Driving line representation based on GPS data
Total time:
Lap time:
Time Difference:
Distance:
102
Video analysis with display of all relevant driving performance data
9_11_15
Driving line representation based on GPS data
9_12_15
CHAPTER9
Evaluation and statistics functions
Detailed evaluations of the driver and vehicle performance are possible on the basis
of precise measured data. All evaluations are possible in comparison with the driver’s
own recordings or the recordings of other drivers.
The evaluation and statistics functions include the following:
•
Racing statistics – number of laps, lap times achieved, total distance, vehicle data,
Electrics and electronics
weather conditions
•
Speed characteristic with display of the generated time difference, supported by
a map view
•
Characteristics showing detailed driving data – including steering angle, brake
pressure, gear, tire pressure, fuel consumption, transverse and longitudinal
acceleration
•
Track-based graphic representations – time difference, transverse and longitudinal
acceleration
Speed [km/h]
Time Difference [s]
Speed, Time Difference
Speed with time difference
9_13_15
Time Difference on Track
Bott Schikane
Alter Hof
Z-Hang
Can-Am-Süd
Nordkurve
Faster
Max. time difference scale
Same
Slower
Time difference on the track
9_14_15
103
Race statistics
Nürburgring Nordschleife
Total time
Total Distance
Electrics and electronics
Start/finish
Number of Laps
Last Lap
Sun
Temperature 19 °C
Fastest Lap
Race statistics
9_15_15
Profile/data management and exchange
This main function allows previous performance data to be accessed again in order to
compare this data with current data. It also permits comparisons in sporting competition
with other drivers. In addition, data export is possible in standardized file formats
(including possibility of analysis on a computer).
The following functions are available for profile/data management and exchange
•
Create and manage driver profiles
•
Manage and create tracks (by driving an introductory lap and track editor)
•
Recording and video management
•
Exchange functions via data import and export
Edit Profile
First Name:
Last Name:
Car:
Tires:
Car Settings:
Creating a profile – information on driver and vehicle
104
9_16_15
CHAPTER9
Track Management
All Tracks
Electrics and electronics
Predefined circuits
9_17_15
Track Management
Creating a new circuit
9_18_15
Track recognition and displays
The live display functions, including the Ghost Car function, are activated if the vehicle
is on one of the over 800 registered tracks worldwide (these include the Nürburgring
as well as all race circuits used by the Sport Driving School).
If the vehicle is not on one of these tracks, recording can still be performed without
the live displays so that evaluations can take place.
Existing race circuits
Over 50 predefined race circuits are supplied so that recording is possible.
Creating race circuits
If a race circuit of the GPS track is not yet defined, the race circuit can be “taught”
by means of an introductory lap or can be created in advance in a map editor.
Tracks from other users can also be imported.
105
Infrared lap trigger
The lap trigger (Figure 9_05_15, yellow frame) is available from Porsche Tequipment
and includes the
Electrics and electronics
•
receiver which is connected in the vehicle with the WLAN interface and
•
the transmitter which is set up at the start and finish line.
Receiver connection point
9_20_15 Transmitter at start/finish line
9_21_15
Lap trigger
The system operates with an infrared signal. The transmitter (white box with four
infrared LEDs with silver surrounds) is set up at the start/finish line and continuously
Receiver in the vehicle
9_19_15
1 Receiver holder
2 Receiver
transmits an encoded infrared signal. It is positioned so that the LEDs are pointing
towards the track at right angles to the driving direction and so that it is at the same
height from the ground as the receiver mounting position in the vehicle
3 Receiver eye
It is sufficient to set up and align the
transmitter parallel to the track by eye
in order to ensure reliable operation.
Transmitter and receiver
106
9_22_15 Transmitter setup
9_21_15
CHAPTER9
Receiver
The receiver is installed in the vehicle (small black box with Porsche logo on the lid).
As soon as the vehicle passes the transmitter, the receiver detects the signal and
sends an electric pulse to the instrument cluster. The lap is then timed if the Sport
Chrono function is active. If there is no lap trigger present, the driver must manually
trigger the pulse by means of the function lever when he drives over the start/finish line.
Electrics and electronics
It is exactly this operation which is replaced by the lap trigger. However, the first lap
must still be started manually (normally the out-lap from the pit). Nothing happens if the
Sport Chrono function is not active, even if the lap trigger sends a signal.
The receiver will also respond to other Porsche lap trigger transmitters. If several drivers
are driving simultaneously on a race circuit with the Porsche lap trigger, only one
transmitter need be set up. In the event that there are nevertheless several transmitters
The infrared signal is encoded so that the
set up along the start/finish straight, the software in the instrument cluster will ignore
receiver does not react to similar systems
further lap trigger signals for three seconds after the start of a new lap. If several
from other suppliers if other drivers are
transmitters are positioned close together, only the first one will be detected and
using similar systems at the same time.
the others will be ignored.
However, several transmitters should
Since the system is an optical system, a direct line of vision is always required
between the transmitter and receiver when the vehicle drives over the start/finish line.
The receiver is installed behind a rear window. It should therefore be ensured that
nevertheless not be positioned directly
next to each other in order to exclude
the possibility of mutual interference.
this window is not too dirty.
Power supply
The receiver is supplied with power via the vehicle electrical system. The receiver
is active as soon as the ignition is switched on and the receiver is connected in the
vehicle. When the receiver is switched on, a red LED flashes three times on the front
of the receiver and then goes out. The LED then always lights up when the receiver
detects the signal from the transmitter.
Receiver in the vehicle
9_19_15 Transmitter power supply
“The receiver is approved by the manufacturer
only for temperatures from +50° F (10° C)
to +140° F (60° C).
It should therefore not remain in the vehicle all
year round.”
9_23_15
107
Transmitter
The transmitter should be set up so that the sun does not shine directly into the
receiver at the start/finish line. Otherwise, the infrared signal of the transmitter may
be masked by the infrared radiation of the sun to such an extent that the receiver is
no longer able to recognize the signal coding. This can be avoided by simply setting up
Electrics and electronics
the transmitter on the other side of the track. The receiver must then also be mounted
on the other side of the vehicle.
Power supply
The transmitter must be supplied with a voltage of 12 V from a starter battery
(not included in the scope of delivery) using the supplied cable. The transmitter
is protected against polarity reversal. In other words, it will not function if + and are mixed up on connection, but will also not be damaged. A red LED in the middle
of the infrared LEDs will light up continuously when the transmitter is active.
Data supply
Data is supplied from existing vehicle sensors and via the additional WLAN interface.
The lap trigger increases the precision of time measurement.
Timing
Lap trigger
Precise time measurement and data supply for Sport
Chrono and Porsche Track Precision App
Display and analysis of the driving performance data
Vehicle data
CAN bus
WLAN interface*
CAN bus
Highly-precise data from the GT4 vehicle sensors
Gateway
CAN bus
in unique Porsche design (analog and digital)
CAN bus
Display and analysis of the achieved driving performance data
Porsche Track
Precision App
Sport Chrono
Vehicle sensors
(ESP, GPS, etc.)
*Cost driver for the Porsche Track Precision App
Data supply for Porsche Track Precision App
108
9_24_15
CHAPTER9
9.4.1 Diagnosis
In the event of malfunctions, targeted diagnostic options are available to the
customer and Porsche dealer to permit fast fault identification and elimination.
Electrics and electronics
Diagnosis instrument
@Porsche.com, @PIWIS
PIWIS Workshop
Manual
Scope
An app diagnosis function allows the connection
status (a-c) to be checked and provides
information about new system updates.
InApp fault diagnosis
Owner’s Manual
Description
Target group
a), b), c)
Customer,
Porsche dealer workshop
a), b)
Customer,
Porsche dealer workshop
A list of frequently asked questions assists
in clarification of operation, functions and
operating problems.
A brief description of the Porsche Track Precision
App functions is provided in the Owner’s Manual.
Function descriptions are integrated in the app.
a)
Workshop Manuals and Guided Fault Finding
are available to the Porsche Service organization
in PIWIS.
b), c)
a)aWLAN interface/app
c) CAN/WLAN interface
WLAN
CAN bus
Customer
Porsche dealer workshop
b) WLAN interface
Diagnosis options
9_25_15
109
Part Number - PNA CMN GT4 16