For developers of automotive control, prototyping and initial tests are a hassle. Commercial solutions are available but the price and especially the price/performance ratio opens the field for more cost effective solutions. Automotive rapid prototype systems seen so far are mainly processor based systems with standard interrupt driven measurement and actuation. Control systems based on high time resolution measurements of for example cylinder pressure are difficult to implement using these systems, neither is it possible to implement controller loops with an extremely high bandwidth in combination with expensive algorithms. Measurement and actuation within the same engine cycle, In Cycle Control (ICC) are not possible. The proposed system is based on a mixed system consisting of one standard x86 processor which is configured through Simulink and a reconfigurable application specific integrated circuit (an FPGA) configured either by relevant FPGA design tools or by Simulink. This layout of the rapid prototype system enables the designer to implement either ICC with very high bandwidth (only limited by the capacity of the injection system) or betweencycle control with medium bandwidth. The aim of this paper is to describe one possible configuration of such a system and to discuss the possible performance outcome of the final system.