Ciao "8tto"
>Quel che so per certo è che l'articolo è scritto in modo veramente
>abominevole.
Lo vuoi in inglese come da documentazione internazionale?
Advanced CVT redesigned for VTEC TURBO application
The CVT automatic transmission has been newly designed especially for its
integration with the new VTEC TURBO engines. It is the result of a two-year
development programme based at Honda’s R&D Centre in Frankfurt that
incorporated a large number of driving scenarios, including congested urban
traffic, open rural roads and high-speed German autobahns.
Mitsuru Kariya, Chief Engineer and Global Project Leader explains: “We faced
numerous major challenges in redeveloping the CVT for the new Civic, but the
highest priority was given to driveability. To ensure we achieved our
objective to give the new Civic ‘soulful performance’, we set out to ensure
drivers would feel utterly confident in the CVT’s ability to engage them,
and we were determined to deliver this dynamic, exciting feel.”
To achieve this engaging driveability, the most significant new design
feature is the turbine twin damper torque converter, which is exclusively
employed for this new application with the VTEC TURBO engines.
Compared to traditional CVT systems which exhibit a ‘rubber band’ feel under
more demanding acceleration, the new unit delivers a totally different, more
direct delivery of engine speed, which in turn results in a more linear
response. It exhibits characteristics similar to those of current-generation
dual-clutch automatic transmissions.
The CVT delivers its more natural drivability via a ‘multi-gear’ feel thanks
to control software that is exclusive to Europe. This simulates seven speeds
through the rev range, with optimised ‘gear change’ mapping providing the
driver with the familiar feel of gear changes. Steering wheel-mounted gear
shift paddles offer the driver the opportunity to take more control both in
automatic and in ‘manual’ mode.
Honda’s CVT features two additional programmes that provide
situation-specific safety and driveability enhancements.
Early Downshift During Braking (EDDB) uses the engine to assist the driver
during braking. When the system recognises a deceleration, downhill, or
cornering situation initiated by the braking system, EDDB automatically
increases the engine speed to provide engine braking. This then allows for
quick re-acceleration after slowing or quick acceleration after cornering.
Fast Off measures how quickly the driver releases the accelerator pedal and
maintains engine revs to provide engine braking in situations where the
driver has released the pedal quickly. This system has been extensively
tested for Europe’s high speed, multi-lane roads. For example, Fast Off
recognises when the driver has prepared to pass a vehicle in front, but is
unable to complete the manoeuvre due to a vehicle in the next lane. As the
driver quickly releases the accelerator pedal to let the vehicle behind pass
by, Fast Off maintains a high engine speed in preparation for completing the
overtaking manoeuvre.
Efficiency of the 1.0 litre VTEC TURBO with CVT exceeds that of most 1.0
litre class competitors with automatic transmissions, while maintaining
similar performance. It also exceeds the acceleration performance of the
previous 1.8 litre five-speed automatic Civic. The performance of the 1.5
litre VTEC TURBO with the CVT was assessed by Honda engineers as
class-leading, with fuel efficiency still among the class best. (Internal
Honda Data)