Development of Nissan Variable Geometry JET Turbocharger 860105
Turbocharged engines exhibit poor transient response, especially when accelerating from low speeds at low loads, due to the inertia of the turbocharger rotating mechanism.
In looking for ways to overcome this disadvantage, we investigated the possibilities of variable geometry turbochargers, and evaluated the performance characteristics of several types. We decided on the single flap type, and established a control method using compressor outlet pressure to control the flap and waste gate valves. Based on the results of experiments with this method, we developed an electronic pressure feedback system which greatly improves transient engine response and, at the same time, engine performance over a wide range of engine speeds.