· 14 ·· 15 ·The new 911 Turbo |
The new 911 Turbo
The second 911 Turbo, launched
in 1977, developed 300 bhp from
a 3.3-litre intercooled engine.
Brake performance was similarly
enhanced, combining four-piston
aluminium fixed calipers with
cross-drilled discs.
In 1993, Porsche launched the
final 911Turbo to feature dedicated
rear-wheel drive. Based on the
Type 964 platform, it used a
3.6-litre engine to achieve a major
boost in output to 360 bhp.
Its Type 993 successor, launched
in 1995, set a range of new
benchmarks in supercar perform-
ance. All-wheel drive provided
greater active safety as well as
better driving dynamics. The
system also had a rear-axle bias
that retained the familiar Porsche
handling characteristics. Twin
exhaust turbochargers offered
better response and a more
harmonious build-up of power. The
last 911 Turbo to have an air-
cooled engine, it offered maximum
output of 408 bhp from a
3.6-litre displacement.
The first water-cooled 911 Turbo,
the Type 996, made its debut
in the year 2000. Also equipped
with all-wheel drive, it used
VarioCam Plus to achieve a major
improvement in all-round fuel
economy. The engine capacity
remained at 3.6 litres, while
output rose to 420 bhp fo r a
maximum speed of 305 km / h
(190 mph). The Type 996 model
was the first 911 Turbo with the
option of Tiptronic S transmission.
The subsequent launch of the
Turbo S version saw a further
rise in output to 450 bhp.
Now, the evolution of this
remarkable car has reached a
new pinnacle of achievement.
Over the following pages, we
will explore every aspect of the
new 911 Turbo.The first Porsche racing car to
feature turbocharged power made
its debut in the early 1970s. The
12-cylinder engine in the legendary
917 used a twin turbo system to
achieve a colossal 1,000 bhp
.
In 1972, the 917/10 with 5-litre
turbo engine claimed the North
American CanAm
championship.
In the following season, the
917/30, developing 1,100 bhp
from a 5.4-litre unit, became the
most powerful racing Porsche of
all time.
This invaluable race experience
inevitably found its way into our
production
road car development.
Just one year later, in 1974,
the 911 Turbo was born. Preceded
as it was by the 1973 oil crisis, it
was considered a
bold undertakingby Porsche. As history would show,
it was the first of many surprises in
the evolution of this legendary car.
The original 911 Turbo featured
widened wheel arches as well as
specially developed front and rear
spoilers. These major aerodynamic
refinements were essential
requirements given the increased
engine performance. Developing260 bhp, the first 911 Turbo could
reach 100 km / h (62 mph) in as
little as 5.5 seconds. Maximum
torque output of 343 Nm was
unprecedented in a 3-litre engine.
This exceptional performance
necessitated a new gearbox
design featuring specially
reinforced gears. Thus began a
new type of Porsche that would
soon acquire mythical status.
911 Turbo 3.0 (1974), 911 Turbo (2006)
Engine cooling.
The 911 Turbo engine features
cross-flow water cooling with fully
integrated coolant management.
This technology ensures a
consistent flow of coolant to each
of the engine’s cylinders. All
coolant passages are integral to
the block, thus eliminating the
need for external hoses. Each
cylinder receives a fresh supply
of coolant which has not been
pre-warmed by the engine. As well
as improving reliability, this
helps to minimise maintenance
requirements. Waste heat from
the oil is transferred to the
coolant via two oil/water heat
exchangers. The coolant is routed
through twin radiator modules
ahead of the front wheels and a
centrally placed unit in the nose.
Engine management.
Optimum performance is assured
at all times with the aid of
the Motronic ME7.8.1 engine
management system. On the new
911 Turbo, this powerful ECU is
responsible for all engine-related
functions and assemblies (see
diagram). Key among these are
the Variable Turbine Geometry
(VTG), VarioCam Plus and
electronic throttle system – one
of the essential prerequisites
for the standard Porsche Stability
Management (PSM). The results:
optimum economy, emissions
and performance, regardless of
driving style.Another important task performed
by the engine management
system is cylinder-specific knock
control. By preventing pre-ignition
at high engine speeds, this
function can avert costly damage
to the pistons and cylinders. Since
temperatures tend to vary in
different parts of the engine, each
cylinder is monitored separately.
If a risk is detected, the individual
ignition timing is adjusted.
The EU-compliant on-board
diagnostics system provides
continuous fault detection and
early warning for the exhaust
and fuel supply systems. The
resulting benefits are active
prevention of harmful emissions
as well as consistent rates of
fuel consumption.
· 40 ·· 41 ·The new 911 Turbo |
Drive
Input data Used to regulate /control
Engine management system
(Motronic ME7.8.1)
Engine load
Pressure upstream from throttle
Throttle-valve angle
Engine speed (from crankshaft)
Camshaft phase angles
Throttle-pedal position
Lambda signal
Knock sensor signal
Ignition
Fuel injection
Throttle valve
Heating elements in lambda sensors
Fuel pump
Fuel-tank venting
CAN interface to
all-wheel drive control unit CAN interface to transmissionMoment interface to Porsche
Stability Management (PSM)
VarioCam Plus
– camshaft phase angle
– valve lift control
Electronic controller for
Variable Turbine Geometry (VTG)
Bypass valve
Secondary air injection
Engine-bay fan
Starter
On-board diagnostics
Air-conditioning compressor
Interface to instrument cluster
Radiator fans
Vehicle speed
Air-conditioning settings
Engine immobiliser status
Clutch pedal switch
Ambient air pressure
Temperatures
– coolant
– airflow upstream from throttle
– engine oil
– air in engine compartment
– ambient air
Exhaust-gas temperature
