This work consists of a computational simulation of a high performance ethanol engine to race Formula SAE Brazil. This study was conducted in order to reduce the performance losses caused by the mandatory usage of an air restrictor in the intake system. It started by redesigning the entire intake system of a Honda 600cc engine, selected by the GTR FSAE Team for this competition. The Ricardo WAVE software was used to developed a base engine model and their results were compared with the initial data (factory default). Then, a new intake system model based on the proposed changes was simulated. After observing the effects that the air restrictor could make to the performance, some actions were taken to minimize them. Finally, an engine fuel conversion to Brazilian Ethanol was carried out. The final results showed a feasible power improvement around 6% when compared with the gasoline engine with air restrictor.