The transient performance of the turbocharged vehicle diesel engine is inferior to the naturally aspirated engine of the same output. This problem tends to appear at high ratings, and becomes more serious as load increases. In this work, two techniques are applied separately and concurrently in order to improve the transient response of the turbocharged engine. In the first, compressed air is fed into the engine intake manifold for a short period in order to satisfy the suddenly increased demand on air supply. In the second method, fuel and air are injected inside a special combustion chamber attached to the engine exhaust manifold. The combustion products are discharged into the manifold as close as possible to the turbine entry in order to increase the energy available to the exhaust turbine.