SFI SYSTEM

The Dual Variable Valve Timing-intelligent (VVT-i) system is designed to control the intake and exhaust camshafts within a range of 70° and 41° respectively (of crankshaft angle) to provide valve timing that is optimally suited to the engine operating conditions. This improves torque in all speed ranges as well as increasing fuel economy, and reducing exhaust emissions.

For the intake valves, the Variable Valve Timing-intelligent by Electric motor (VVT-iE) uses electric motors to control the valve timing. Because VVT-iE is actuated by electric motors, it can perform optimal valve timing control even when the engine oil pressure is low, such as when the engine oil temperature or the engine speed is low. For conventional VVT-i, the maximum retarded valve timing during engine operation is determined by the retarded valve timing required when starting the engine. Because this system can control the valve timing during startup, it is possible to further increase the maximum retarded valve timing as the maximum retarded valve timing is no longer limited by the timing required to start the engine.