automatic transmission lexus LFA 2012 Technical Information / LEXUS 2012 LFA: INSIDE THE LFA

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Shifting
■
■Dry single-plate clutch
A dry single-plate clutch has been adopted to enable a direct engagement feel. The
clutch in the LFA is a hydraulically
actuated unit controlled by the ECU in order to
ensure quick and precise operation.
A pump within the hydraulic power unit generates the hydraulic pressure needed
to operate the clutch. This pump is powered by an electric motor to ensure a stable
supply of hydraulic pressure. In some cases, one can hear the sound of this electric
motor operating prior to the engine starting. This operation provides the hydraulic
pressure needed to disengage the clutch prior to starting the engine.
Because the LFA employs a dry single-plate clutch, it will not exhibit the slow speed
creep associated with a conventional automatic transmission. The driver must normally
depress the accelerator pedal to accelerate, even in ultra-slow speed situations such
as a traffic jam.
Diaphragm spring
Clutch disc The clutch disc is a compact size [9.45
in. (240 mm) diameter] and features
friction material designed specifically
to comply with the engine’s high-output
characteristics. The clutch cover is
c o n s t r u c t e d f r o m a l u m i n u m f o r a
precisely balanced, low-inertia design
that contributes to outstanding engine
response.