The study featured in this paper presents a CFD, RBF mesh morphing and lap time simulation-based analysis method to investigate the effect of aerodynamic drag on go-kart performance. A bodywork design exploration is performed, employing an automatic response surface optimisation, to evaluate effects of its shape on aerodynamic penetration. The effect of driver size is explored as well by adapting the mesh according to a parametric mannequin positioning workflow. Results of the design exploration process highlight a very good optimisation of the baseline configuration with respect to aerodynamic efficiency. On the other hand, driver size reduction produces a noticeable drag decrease in the order of 4.5%. To translate registered drag changes into performance variations, an in-house lap time simulator based on a lumped parameter model is adopted. Lap time for two different karting circuits are simulated in high and low drag configurations resulting in lap time variations in the order of 0.1/0.2 sec.