Off-design performance of individual gas turbine components is addressed. Since compressor maps are the key to a high-quality performance model and realistic maps are typically only available to the manufacturers, we describe in great detail how to scale and adapt existing maps. Examples of simple and advanced scaling methods are illustrated using the features in Smooth C combined with GasTurb. We review the pros and cons of alternative formats for turbine maps, using Smooth T. We discuss the options in use for modeling intakes, covering the range of subsonic and supersonic aircraft as well as land-based gas turbines. We describe how to model combustors and show the good correlation to empirical data. We look at the potential benefits of mixing the hot and cold exhaust streams, with a worked example of a mixing calculation. The chapter concludes with detailed discussions on modeling afterburners as well as nozzles, both convergent and variable convergent–divergent.