2004 PORSCHE 911 TURBO fuel type

· 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)

To apply these benefits efficiently
to the road, we required another
innovation in sportscar design: all-
wheel drive with Porsche Traction
Management (PTM). Using an
electronically controlled multi-plate
clutch, this intelligent technology
provides variable drive to each
axle. The front/rear split is con-
tin
uously adjusted based on current
road conditions and driver inputs.
Although biased towards the rear,
the front receives more power
whenever the situation requires.
Porsche Traction Management
is specifically designed to
optimise driving dynamics. The
additional traction provided by
both the all-wheel drive system
and PTM represents a major
improvement in active safety,
especially in the wet or on snow.
Another benchmark technology
on the new 911 Turbo is the
standard braking system. The
front and rear discs have a
generous diameter of 350 mm.On the optional Porsche Ceramic
Composite Brake (PCCB), the
front diameter is increased to
380 mm.
Other standard features on the
new 911 Turbo include a new
evolution of Porsche Stability
Management (PSM) as well as
Porsche Active Suspension
Management (PASM) featuring
electronic damper control.
A
limited-slip differential is available
for the rear axle as an option.
For even greater performance, the
car can be equipped with the
optional Sport Chrono Package
Turbo. Key features include
an ‘overboost’ function which
provides as much as 60 Nm
of additional torque under
acceleration. When the throttle
is fully open, the boost pressure
is increased temporarily by
approximately 0.2 bar. The
electronic throttle map is
also adjusted to give a more
dynamic response to pedal
inputs.
Other modifications when ‘Sport’
mode is selected include a major
rise in the trigger threshold used
by Porsche Stability Management
(PSM). The all-wheel drive system
featuring PTM provides a similar
increase in driver involvement
by sending a greater proportion
of drive torque directly to the
rear wheels. PASM provides a
stiffer suspension setup enabling
faster turn-in and better road
contact.
Another major development
on the new 911 Turbo is the
car’s lightweight design and
construction. The doors and front
lid are made from aluminium
which offers a range of benefits
in terms of both performance
and economy. Every gram of
weight on every component
is there for a specific reason.
As a result, the standard model (with six-speed manual gearbox)
weighs just 1,585 kg. Even more
impressive are the power-to-
weight ratio of 302.8 bhp per
tonne and surprisingly low fuel
consumption.This powerful potential is, of
course, matched by exemplary
ride quality on every type of
road. This rare combination of
performance and comfort is one of the distinguishing features
of the 911 Turbo.
· 18 ·· 19 ·The new 911 Turbo |
The new 911 Turbo

vanes are opened further. By
varying the vane angle, it is
possible to achieve the required
boost pressure over the entire
engine speed range. As a result,
there is no need for excess-
pressure valves as found on
conventional turbocharged
engines.
· 34 · · 32 ·· 33 ·The new 911 Turbo |
Drive
Variable Turbine Geometry (VTG).
Creating the optimum turbo for every scenario.
known as ‘turbo lag’, means there
is virtually no turbocharging effect
at lower engine speeds. To
overcome this problem, the twin
water-cooled turbochargers on
the new 911 Turbo feature Variable
Turbine Geometry (VTG). With
this technology, the gas-flow from
the engine is channelled onto Larger turbo units, which create
lower back-pressure at higher rpm,
take considerably longer to spin
up under power due to the large
cross-sectional area and relative
inertia of the heavier turbine.
Generally, this type of turbo will
only be effective in the medium
rpm range. This phenomenon,
Turbocharger guide vane adjuster Turbocharger with Variable Turbine Geometry (VTG)
up easily to its optimum speed.
The key disadvantage of using
a smaller turbo is that the back-
pressure generated at higher
engine speeds causes a significant
reduction in performance.
Resistance is caused by the smaller
cross-sectional area through which
the exhaust is required to flow.
The 911 Turbo has always been
synonymous with performance.
Now the car is more capable than
ever thanks to a new twin turbo
system featuring Variable Turbine
Geometry (VTG).
On a conventional turbocharger,
the exhaust flow drives a turbine
that is connected to a compressor
in the air intake tract. By ‘squeezing’
the incoming air, the amount
of oxygen in a given volume isincreased. Since compression also
causes an increase in temperature,
the air must be passed through
an ‘intercooler’ unit. With more
oxygen present in each cylinder
charge, more fuel can be burnt
yielding greater energy. Since
higher exhaust pressures generate
corresponding loads on the intake
side, the intake pressure must
be carefully controlled in order
to protect the engine. On the new
911 Turbo, the ‘boost pressure’ islimited using ‘wastegate’ valves
that bypass excess pressure
around the twin exhaust turbines.
Another important factor is the
size of the turbo unit. Since a
smaller turbine has a lower mass,
it generally responds more quickly
to increasing pressure, spinning
the turbines via electronically
adjustable guide vanes. By
changing the vane angle, the
system can replicate the
geometry in all types of turbo,
large or small.
With Variable Turbine Geometry
(VTG), it is possible to achieve
higher turbine speeds, and thus
higher boost pressure, at lower
engine rpm. Cylinder charging issignificantly improved, with a
corresponding increase in both
power and torque. Maximum
torque is reached at lower rpm
and is retained across a wider rev
range. A full 620 Nm is available
from as low as 1,950 rpm up to
5,000 rpm. Every throttle input is
met with exceptional response
and phenomenal acceleration.
When the boost pressure reaches
its maximum value, the guide