Use of simulation to predict dynamic behavior of engine mounted components play a key role to assist designer´s decision. This paper presents main steps taken to increase fidelity level of a simulation model in comparison with vibration tests of an ignition coil. Dynamic requirements focused by this work include modal and harmonic analysis. Significant improvements on results were achieved mainly through the inclusion of a fixture on simulation model similarly as used on real shaker. A simulation guideline based on commercial Finite Element Analysis (FEA) software was created which allows engineers to get a better first-time product capability before design freeze avoiding tests recursions.