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The 911 | Engine
The spray and cone angles
have been optimized for torque,
power output, fuel consumption
and emissi ons by enabling a
homogeneous distribution of the
air/fuel mixt ure and, therefore,
effective combustion. With direct
inje ction, the EMS SDI 3.1 engine
control regulates injection timing
individually for each cyli nder, as
well as the injecti on rate for each
cylinder ba nk. This optimizes
the combustion process and
fuel economy. A hot-film air
mas s meter takes care of the
airflow, so that the combustion
chambers cont ain exactly the
right mixture at all times.
At up to 32 00 rpm, the engine
operates with dual injection; at
up to 2500 rpm, it even works
with triple injection. The required
volu me of fuel is distributed
between two or three s equential
inje ctions , respectively—for faster
heating of the catalytic converters
afte r a cold start and for greater
torque in the upp er load ran ge.
DFI improves the internal cooling
of the combustion ch amber by
having the mixture prepared
directly in the cylinder. This
allows for a higher compression
ratio (12.5:1), which help s to
deliver more output along with
enhanced
engine efficiency.
Injection is reg ulated by the
elec tronic engine management
system. The exhaust gas
cle aning system ensures that
emissions
remain well below
the str ict limits
of the LEV II
emissions standard,
thus helping
to protect the environment.
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