A Turbocharged Engine with Microprocessor Controlled Boost Pressure

A prototype boost pressure control system, utilizing a microprocessor to govern the wastegate settings, has been developed and tested on a turbocharged petrol engine with intercooler. The Volvo Computer Controlled Turbo (VCCT)-system allows optimum boost pressure settings for varied operating conditions.

A knock detecting system retards ignition and lowers boost simultanously, minimizing torque loss with no increase of exhaust gas temperature. For high performance turbo engines this strategy is important, since at continous high power operation no increase in thermal loading (with risk for degraded durability), can be accepted.

Vehicle tests show significant improvements in performance and fuel economy.