2009 PORSCHE 911 fuel pump

The car was made technically
possible by an invention from 1905.
The Swiss engineer, Dr. Büchi,
utilised the energy of the flow of
exhaust gases to increase the
ef ficiency of combustion engines.
You don’t need to be an engineer
to understand the practical benefits
of this. Turbocharging means
a tremendous gain in power for
comparatively small engine
displacements. The advantage of
small-
displacement engines is
particularly
felt in the lower and
middle load ranges – in other
words, during everyday driving on
the road. In these conditions, fuel
consumption and CO
2 emissions
figures are significantly lower than
those for larger engines.
Another advantage is the compact
engine size which reduces weight.
The engine takes up less space
and keeps the overall vehicle
weight down. In short, agilit y

and dynamic performance are
increased and fuel consumption
is decreased.
Of course, in 1974, the technology
was still in its infancy. The idea
needed to mature, but the fact
remained that it worked. What
started out as a scheduled produc -
tion run of 400 vehicles has b e -
come a lifetime’s work.
Over the years, alongside con tinual
increases in power output, the
911 Turbo has seen the introduc -
tion of a wide variet y of technolo -
gies to improve handling and
dynamic performance as well as
fuel consumption and efficiency.

Examples from 1977 include
above all the intercooler,
which improved turbocharger
efficiency, and the cross-drilled
brake discs, which increased

braking per formance and reduced
unsprung masses. In 1990, the
911 Turbo based on the Type 964
was the first to be equipped with
a regulated cataly tic converter as
st a n d a rd .
The t win -turbo engine introduced
in 1995 performed excellently,
delivering a significantly more
harmonious build-up of power
and making the 911 Turbo a

much more composed and there-
by more fuel-efficient vehicle.
All-wheel drive was introduced

for the first time, increasing both
traction and safet y.
A major step towards greater
ef ficiency was achieved in 2000
with the launch of the 911 Turbo
based on the Type 996. This saw
the use of technologies that
are also to be found on the latest
911 Turbo generation. VarioCam
Plus reduced fuel consumption
drastically, whilst the extending
rear wing, through its abilit y to
change position, complemented
the already exemplary aero -
dynamic performance.
In 2006, the launch of the

911 Turbo based on the Type 997
revealed a revolution in turbo -
charging, with the advent of
Variable Turbine Geometry (V TG).
More power. More torque. Less
fuel. Less CO
2. Porsche was
the first car manufacturer that
was able to use this technology
in standard-production petrol
engines. And so far is the only
one to do so.
And today? The principle behind
the 911 Turbo is still one of power
and ef ficiency and consequently
is just as valid as ever.
Direct fuel injection (DFI) improves
power output, torque and engine
response whilst also reducing fuel
consumption and CO2 em issio ns.
The Porsche Doppelkupplung
(PDK), or double-clutch gearbox,
shortens gearshift times, elimi -
nates any interruption in the flow
of power and increases ef ficiency
thanks to the long-ratioed 7th
gear. Also doing their bit are the
expansion intake manifold and
on - demand oil pump.
Let ’s get down to the details.
The 911 Turbo concept | Ef ficiency
· 10 ·· 11 ·

Direct fuel injection (DFI).
On the 911 Turbo models, DFI
injects the fuel with millisecond
precision directly into the com-
bustion chamber at up to 140 bar
via electromagnetically actuated
injection valves, thus ensuring homogeneous distribution of the
air/fuel mixture and consequently
ef ficient combustion.
In the direct injection system, the
EMS SDI 3.1 engine management
system adjusts the injection

timing individually for each
cylinder and the injection quantit y
for each cylinder bank. This

optimises both the combustion
curve and fuel consumption.
Dual injection is implemented
at engine speeds of up to
3,200 rpm and triple injection up to 2,700 rpm to ensure faster
catalyst warm up after a cold
start and more torque in the
upper load range. The required
quantit y of fuel is distributed to
t wo or three successive injection
processes per cycle. DFI improves the internal cooling
of the combustion chamber by
forming the mixture directly in the
cylinder. This has made it possible
to increase compression (9.8
: 1),
resulting in more engine power
and even greater efficiency.
Integrated dry-sump lubrication.
Integrated dr y-sump lubrication
ensures a reliable supply of oil
even when a sport y driving st yle
is adopted. It also has additional
cooling functions.
The oil tank is located in the
engine, thereby eliminating the
need for an external oil tank.
A total of seven oil pumps ensure
the supply of oil. Six of those
return the oil from the cylinder
heads and exhaust gas turbo -
chargers directly to the oil sump
where a seventh oil pump feeds
oil directly to the lubrication
points in the engine.
To reduce drive losses and
increase ef ficiency, an electronic
on - demand oil pump is used.
This means that the oil pump is
operated at high power when
there is high demand and at low
power when there is low demand.
The result is an optimised oil
supply appropriate to require -
ments, lower fuel consumption
and fewer emissions.

Performance | Engine
· 32 ·· 33 ·

Expansion intake manifold.
More power for less fuel. What
sounds absurd is sometimes
quite simple. You just have to
have the nerve to question
prin ciples that are seemingly
writ ten in stone.
The 911 Turbo and 911 Turbo S
models have an innovative expan -
sion intake manifold that was
used for the first time on the latest
911 GT2. Its unique operating
principle is unlike any thing ever
featured on existing induction
systems. Our ‘expansion’ intake
manifold is a radical development
that is the polar opposite of the
resonance principle used on con -
ventional turbocharged engines.
A resonance manifold increases
engine output by forcing addi
tional
air into the combustion chambers.
To do this, the manifold is designed
in such a way that the air – which
vibrates due to the action of the
valves – is in a compression phase
as it passes through the inlet ports.
Unfortunately, compression not
only increases air volume, it
also increases air temperature
and this has a negative effect
on ignition.
Our expansion manifold simply
turns that principle around. The
internal geometry is radically
different from that on a resonance
intake system. Key modifications
include a longer distributor pipe,
with a smaller diameter, and
shorter intake pipes. As a result,
the air is in the expansion phase
as it enters the combustion

chambers. Since expansion always
cools, the air/fuel temperature is
lower and ignition is significantly
improved – thereby increasing
performance.
Of course, the amount of air that
enters the engine under expan -
sion is less than it would be under
compression. To compensate
for this, we’ve simply increased
the boost pressure. The resulting
increase in temperature – again
through compression – is immedi -
ately offset by the uprated inter -
coolers. Instead of hot compressed air
entering the combustion

chambers, we now have cooler

air generating more power and
torque. As a consequence, there
is a major improvement in engine
efficiency and therefore lower fuel
consumption even under heav y
loads and at high revs.
As we said, sometimes you just
have to question established
ideas.
Exhaust system.
The exhaust system is made
from stainless steel. Its cataly tic
converters are extremely heat-
resistant, yet quick to reach
temperature – and thus optimum
performance – when the engine
is started from cold.
Advanced exhaust gas technology
ensures compliance with stringent
emissions standards, e.g. Euro 5
in EU markets, LEV II/ LEV in the
USA.
Servicing.
The 911 Turbo and 911 Turbo S
models are designed for a long
life. A self-adjusting belt drives
the generator, power-steering
pump and air-conditioning com -
pressor. Valve clearances are
adjusted hydraulically, thus avoid -
ing the need for any adjustment
work. The camshafts are driven
by timing chains that require
no maintenance and the ignition
system, with the exception of
the spark plugs, is also mainte -
nance-free. The cars come with
a t wo -year unlimited mileage
w a r ra n t y.
The long service intervals (see
separate price list) keep costs
and labour times down and save
resources, since fewer service
products and consumable parts
are used.
Performance | Engine
911 Turbo engine and exhaust system
· 40 ·· 41 ·