notevoli differenze ? Per ora che si sappia è il software gestione motore che è differente e garantisce l'iniezione in due fasi che è un esclusiva dell'alfa romeo , mentre per il resto ho dei dubbi in quanto non riesco chiaramente a quantificare appieno l'intervento del gruppo fiat sul progetto di questi v6.
questa è un estratto della prima parte di 2 articoli riguardanti i GM v6 global HF:
“high feature” philosophy.
Conceived For Flexibility
From the program ‘s start in February 1999, a prime objective was to develop a
highly flexible “platform” from which a matrix of possible variants could be
developed. The new V6 was designed for true global duty: future variants will
power a variety of vehicles worldwide. Several components and features will be
common to all global V6 family engines, however, reflecting the high feature
strategy to provide high levels of performance, technology and refinement,
combined with the reliability and cost-effectiveness for which GM Powertrain is
world-renowned. All global V6 engines will employ:
l All-aluminium construction
l Dual overhead camshaft (DOHC)
l 4-valve-per-cylinder valvetrain
l Roller-finger follower valvetrain
l Continuously variable cam phasing
l Electronic throttle control (ETC)
l Durable forged-steel crankshaft
l Piston-cooling oil jets
l Coolant-loss protection software
l GM’s Oil Life System
l 32-bit microprocessor
l Coil-on-plug ignition
“Since the start the global V6 project team was determined to introduce a V6
engine superior to all in the industry, and in record time,” said Tim Cyrus global
V6 chief engineer.
“The team tapped GM’s vast technical expertise an developed a V6 with industry
leading reliability, flexibility, package size, pleasibility, efficiency and value. This
engine was developed by a unique team with talented members from across
each of the global GM engine departments and suppliers We have delivered an
engine that can be easily integrated into most platforms, has industry leading
NVH and performance with three discrete combustion systems MPFI, SIDI and
turbo.”
l The global engine family encompasses a range of displacements. In
addition to the 3.6L variant that marks the launch of the new engine in production
vehicles, there also are 2.8L and 3.2L variants. Engine displacement can be
expanded to 3.8L, or as large as 4.0L when the cylinder liners are eliminated in
favour of special cylinder bore coatings. Smaller-displacement global engine
variants are particularly crucial in world markets where market conditions and
competitive issues demand high performance from smaller engines.
Whatever the displacement, the global V6 engine family promises high specific
power and torque competitive with the best contemporary V6 engines. The wide
range of potential global V6 engine displacements and configurations allows
power and torque output perfectly suited to a variety of vehicle, platform, drive
configuration or market requirements. The global V6 engine family will effortlessly
produce power ranging from approximately 200 hp to more than 370 hp; torque
output will run from 200 lb-ft to in-excess of 350 lb-ft.
l In addition to a wide range of displacements, the basic global V6 engine
architecture was designed to support a host of feature and “content” options,
establishing a broad matrix of potential engine configurations. Aside from the
normally aspirated/sequential port fuel injection “foundation” architecture,
possible major variants include:
• A spark-ignition direct-injection (SIDI) V6 of either 2.8L or 3.2L
displacement. Gasoline direct injection is a technology that can produce fuel-
economy gains on the order of 10 percent, with no loss of performance. To be
most responsive to regulatory and other market considerations, the global V6
engine design has provisions for both stratified-charge (lean-burn) and
stoichiometric-charge SIDI architectures. SIDI engines are rapidly expanding in
Europe and other regions with high fuel costs.