As the world is evolving faster and technology gets cheaper and more powerful, simulations are proving to be more and more beneficial. Simulations allow for faster development with less lead time between iterations which means that product versions can be released more often and at less cost. The automotive industry is heavily affected by emission legislation and environmental politics. The development of more environmentally friendly engines forces the rate of development to speed up. Simulations allow the industry to keep up with the increasing requests for more complex systems. For software development, it speeds up the process significantly. Although real-life testing in engine test cells and test cars still sets the foundation for and validates the results of the simulations, simulations can drastically decrease the amount needed. Less unnecessary real-life testing with bugs in the software causing wasted time and cost. In the meantime, more iterations can be tested in a smaller time frame, making the actual real-life testing more valuable and giving. The aim of this thesis is to develop a method to convert an accurate but relatively slow simulation model of the airflow through an engine, into a faster-running format preparing it to run in close to Real-Time and with a fixed timestep. Then exporting the converted model as a functional mock-up unit, FMU, a standardised entity, part of the Functional Mock-up Interface standard. The FMU was to be used in Software in Loop, SiL, simulations using it in cooperation with Matlab Simulink and Synopsys Silver. The SiL environment is then to be used to develop and test calibration software for the engine in question.