Honda’s VTEC and Toyota’s VVTi

What are VTEC and VVTi?

The real secret of developing efficient petrol engines is in the supply of air, the art which has been researched since the internal combustion engine was seen. The VTEC by Honda and VVTi by Toyota are important steps in achieving high efficient engines.

VTEC (Very Talented Engine Control) and VVTi (Variable Valve Timing with Intelligence) are similar in effect but differ in technology. VVTi engine features in Toyota Camry, Toyota Innova, Toyota Corolla, Toyota Prado and VTEC engine powers Honda Accord, Honda CR-V, Honda Civic, Honda City.

Honda’s VTEC:

Honda’s VTEC uses two sets of cam shaft profiles – one for low and mid range rpm and another for high rpm operation. An electronic switch shifts between the two profiles at a specific rpm to increase peak horsepower and improve torque. When you ride Honda’s car, you can both hear and feel the change when the ‘VTEC’ kicks in at higher rpm to improve performance. While this system does not offer continuously variable valve timing, it can make most of high rpm operation while still providing solid driveability at lower rpm levels.

Toyota’s VVTi:

Instead of on/off system that VTEC employs, Toyota’s VVTi employs a continuously variable system that maximizes valve timing throughout the revolution range using a hydraulic system rather than the mechanical system to alter the intake cam’s phasing

Honda’s VTEC Vs Toyota’s VVTi:

The main difference between VTEC and VVTi is that VVTi maintains the same cam profile and alters only when the valves open and close in relation to engine speed. Also, VVTi works only on the intake valve while Honda’s VTEC has two settings for the intake and exhaust valves, which makes for a more dramatic gain in peak power than VVTi can claim.

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