The focus of this paper is to discuss the modeling and control of intake plenum pressure on the Powertrain Control Research Laboratory's (PCRL) Single-Cylinder Engine (SCE) transient test system using a patented device known as the Intake Air Simulator (IAS), which dynamically controls the intake plenum pressure, and, subsequently, the instantaneous airflow into the cylinder. The IAS exists as just one of many devices that the PCRL uses to control the dynamic boundary conditions of its SCE transient test system to make it “think” and operate as though it were part of a Multi-Cylinder Engine (MCE) test system. The model described in this paper will be used to design a second generation of this device that utilizes both continuously and discretely actuating valves working in parallel. Throughout this paper it is possible to find a description of the operation and performance of the current IAS system, the goals for the second generation IAS system, and the means by which the authors are pursuing these goals. Iterations of the dynamic model will be described and results from these iterations will be shown and discussed. These results will then be used to shape the continuing research into the construction of the second generation IAS.