Porsche 911 GT2 -, Брошюра

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The 911 GT2 | Drive
Unfortunately, compression not
only increases air volume, it also
increases air temperature and this
has a negative effect on ignition.
Our new 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.
Expansion intake manifold.
More power than a 911 Turbo -–
from the same engine? Not easy.
But feasible, which is why it
required yet another spectacular
innovation from Porsche.
The 911 GT2 has an innovative
expansion intake system with a
unique working principle which
overturns the methods previously
used. Our ‘expansion’ intake mani-
fold is a radical new development
that is the polar opposite of
the resonance principle used
on conventional turbocharged
engines.
A resonance manifold increases
engine output by forcing add-
itional air into the combustion
chambers. To do this, the mani-
fold 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.
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
expansion is less than it would
be under compression. To
compensate for this, we’ve simply
increased the boost pressure
from the turbochargers by
approximately 0.2 bar. The result-
ing increase in temperature –
again through compression – is
immediately offset by the uprated
intercoolers.
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
heavy loads and at high rpm.
A simple solution, but then that’s
often the way when you take
a new approach to old ideas.
Expansion intake manifold