SYSTEM OPERATION OF I-VTEC HONDA ENGINE

If you thought the normal VTEC was remarkable, i-VTEC will prove even more impressive! The ‘i’ brings to the VTEC concept "intelligent" combustion control technologies that optimize fuel economy, boast cleaner emissions and achieve higher performance. Incorporating VTC – Variable Timing Control – which continuously adjusts the intake valve timing to best match the current engine load, the driver enjoys abundant low-rpm torque, exhilarating high-rpm power and outstanding fuel efficiency.

With the i-VTEC system, there is a new camshaft to make it possible for continuously-variable camshaft phasing across the engine's entire power band. During typical operation, the intake camshaft timing is almost fully retarded at idle to help provide more stable idling while reducing exhaust emissions. As the engine speed increases, the intake camshaft is advanced, opening the intake valve sooner and providing additional valve overlap.

This results in increased fuel economy (by reducing pumping losses) and a further reduction in exhaust emissions (by creating a large, internal exhaust gas recirculation effect). Also, to generate additional power throughout the rev range, the intake camshaft is continuously varying the amount of advance or retard, adjusting in a split second to provide additional power when needed.

i-VTEC regulates the opening of air-fuel intake valves and exhaust valves in accordance with engine speeds

By regulating valve opening to match engine speed, the agile i-VTEC engine adjusts its characteristics to realize both superior power and low fuel consumption.