System Description: VTEC/VTC: Notes

2011 Honda CR-V EX, 2.4 RE3, MZJASECTION Notes
  • The i-VTEC system has a variable valve timing control (VTC) mechanism on the intake camshaft in addition to the usual VTEC.

    This system improves fuel efficiency and reduces exhaust emissions at all levels of engine speed, vehicle speed, and engine load.

  • The VTEC system changes the intake valve lift and timing by using more than one cam profile.
  • The VTC system changes the phase of the intake camshaft via oil pressure. It changes the intake valve timing continuously.
Fig 1: Torque Curve Graph
G06610243Courtesy of AMERICAN HONDA MOTOR CO., INC.
DRIVING CONDITION DESCRIPTION

Driving Condition VTC Control Description
Light-load Base Position For stable combustion the cam angle is retarded, and reduces the entry of exhaust gas into the cylinder.
Medium/high-load Advance Control Cam phase angle is controlled to optimize valve timing, improving fuel efficiency and reducing emissions.
High speed Advance-Base Position To reduce pumping loss, the intake valve is closed quickly. This gives the air/fuel mixture a charging effect that helps to maximize engine power.
RENDER: 1.0x

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