Minimizing the lap time for a given race track is the main target in racecar development. In order to achieve the highest possible performance of the vehicle configuration the mutual interaction at the level of assemblies and components requires a balance between the advantages and disadvantages for each design decision. Especially the major shift in the focus of racecar powerunit development to high efficiency engines leads to a development of lean boosted and rightsized engines. In terms of dynamic engine behavior the time delay from demanded torque to provided torque could reveal an influence on lap time performance. Therefore maximizing the full load behavior as sole objective is insufficient to gain minimal lap time. By means of continuous predictive virtual methods throughout the whole development process the influence on lap time by dynamic power lags i.e. caused by the boost system, can be recognized efficient even in the early concept phase. Traditional quasi steady state (QSS) lap time methods are suitable to calculate the sensitivities of basic parameters and are often used, even with extending algorithm, for vehicle dynamic investigations. This leads to simplified engine models like steady-state engine maps or even the transient surrogate model, which tries to describe the engine dynamics by transfer functions. Insufficient precision, limited prediction ability and the inefficient use of models are the related disadvantages. Within this examination a new method is introduced, that combines highly detailed 1D gas dynamic engine models with the quasi steady state lap time method. This allows a predictive comprehension of lap time influence for different engine design parameters with the possibility to operate in an environment of detailed vehicle dynamic description. Moreover the direct applicability of 1D gas dynamic engine models increases also the efficiency of virtual engineering tools. In addition to the detailed explanation of the method this examination gives an insight into a continuous model supported development process of a boosted 2.0l 4-cylinder race engine. Analysis to the predictive capability and an exemplary investigation of basic boost system parameters with lap time influences of weight, aerodynamics, steady-state and dynamic engine performance shows the forecast potential of this novel approach.