Two comprehensive programs for the complete cycle synthesis for compression ignition engines are briefly described. The programs include the intake pipes, the exhaust pipes, and the turbocharger if this is fitted. The combustion in the power cycle is represented by a simple heat release model as described by Whitehouse, et al, and the heat transfer is computed by the method of Annand. The wave action in the intake and exhaust system and the gas exchange process in the cylinder are computed by methods described by the author in earlier papers. Recent improvements include heat transfer in the pipe system, supersonic flow, and the exact dimensioning of the pipe system. The matching of the turbocharger within the engine is described, based on quasi steady methods, and a discussion of the possible limitations of this approach is given.Comparison of experimental results taken on engine tests with the computed predictions, are given. The use of the program to facilitate engine design is illustrated with examples.