Electronic fuel injection (EFI) is a complex system, many parts are connected together from mechanical parts to electronic parts to control the internal combustion engine. It must ensure many different works and the most important thing in motorsport to achieve is power optimization. High power and engine responsiveness are often desired to gain a competitive edge. Usually motorsport enthusiast will upgrade the car standard with aftermarket components such as higher rating turbo, longer duration camshafts and exhaust system. These are difficult to approach, time-consuming and expensive tasks compared to the ECU calibration method. And in Vietnam, most customers who want to change vehicle performance are based on the Remap method on Factory ECU. By using vehicle performance regulation method with piggy-back ECU, it is easier for the user to adjust than the popular Remap method. With advantages such as low cost and easy installation. And currently there are very few documents describing and evaluating the effectiveness of piggy-back ECU installed in vehicles. So in this paper, experimentally to reconstruct the electronic fuel injection system with piggy-back ECU was performed, then simulated the control algorithms of the electronic fuel injection system on LabVIEW and compared the results with the experiment, based on the simulation model of the operation algorithm of the EFI system with many cases in different load engines and engine speeds. Simulation results are used to evaluate the algorithm on the piggy-back ECU.