This paper presents a novel turbocharging system applied to four-stroke diesel engines, which is named modular multipurpose pulse converter (MMPC) turbocharging system. Two-dimensional steady flow simulations of the MMPC turbocharging system are performed with STAR-CD code. A one-dimensional unsteady flow simulation code finite volume method and total variation diminishing (FVM-TVD) has been developed. Using FVM-TVD, flow predictions in the diesel engine 8L250Z are carried out in the unsteady state with the mixed pulse converter (MIXPC) turbocharging system and MMPC, respectively. It is found that the MMPC system is more capable of reducing flow interference and has less variation of the scavenging coefficients for all cylinders than the MIXPC system. To validate the prediction results, experiments of the diesel engine 8L250Z equipped with the pulse converter (PC) turbocharging system, the MIXPC and the MMPC turbocharging systems are carried out. Experimental results show that the MMPC makes exhaust gas temperature lower before turbine and at each cylinder head face than the PC and the MIXPC. A diesel engine 20VPA6BSTC was simulated on series adaptability of the MMPC system. The simulation results reveal that the MMPC turbocharging system could be applied to four-stroke high-power diesel engines that may have any number of cylinders and different firing orders. Copyright (C) 2007 John Wiley & Sons, Ltd.