Control algorithm development for typical Engine Management System is a challenging task. To develop a reliable control algorithm, proper closed loop testing environment is required. In such development activity, it is of prime importance to validate the algorithm on a standalone target engine. This can be achieved in engine test cell where the actual engine will be controlled by prototype ECU. But this process has drawbacks like higher testing cost, time consuming, non-reusability of test bed etc.Simulation based engine plant model development for closed loop ECU testing is an effective technique for such application. Various generic engine models are available for such application.to suit a particular target engine these model need to be parameterized with precise engine data.The vehicle parameters used for parameterization are typically obtained from actual test and engine design data. This paper elaborates the process and challenges faced while parameterization and validation of engine plant model in simulation environment and steps followed while parameterizing a two cylinder gasoline engine to suit EMS development. Simulations were carried out in Model In Loop (MIL) and Hardware In Loop (HIL). Validation results were compared with actual vehicle data from dynamometer trials and are presented in corresponding sections.