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  # 149
Suzuki VVT Ensuring Optimum Performance
More detail on Suzuki's current jewel in the crown!
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the Suzuki DF250

Suzuki DF250 Torque curve

When designing the world's most powerful V6 4-stroke outboard - the Suzuki DF250 - the specification demanded optimum power and performance throughout the power band. An essential requirement that is virtually unique to high performance marine engines is for maximum torque at low to medium revs to lift the craft out of the hole and on to the plane rapidly without loss of performance at top end.

The Suzuki DF250's engine generates a massive 250hp with high performance camshafts which control the timing of the opening and closing of the valves and, therefore, the fuel/air mixture, providing excellent top end power. To harness this in meeting the demand for maximum torque at low to mid rpm Suzuki developed their exclusive variable valve timing system (VVT). Unlike other outboard systems, it

continuously varies the intake valve timing according to engine revs. The result is ideal air/fuel mix at all times. When combustion takes place in the cylinder this generates optimum power from each stroke of the six pistons regardless of engine speed.

It is a common belief that the intake valve on an engine opens after the exhaust valve closes. However, in fact the 4-stroke engines generally operate with a momentary overlap when both valves are open. By controlling the length of the overlap by advancing or retarding the opening of the intake valve using Suzuki VVT the engine generates a stronger power stroke in low and mid range whilst improving fuel economy. This innovative Suzuki system achieves this by using hydraulic pressure to automatically adjust the intake valve timing.