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Intake tuning is a relatively simple alternative to turbochargers and superchargers as a means of augmenting engine performance. Capitalizing on air flow harmonics at specific engine speeds, intake tuning forces more air into the engine cylinders, resulting in greater torque and power. Concepts such as Helmholtz Resonance Theory and Reflective Wave Theory help to describe the physical phenomena that contribute to intake tuning, but previous studies have generally found that computer models utilizing computational fluid dynamics (CFD) are needed to accurately predict performance effects. The current research involves testing various intake runner lengths and cross section geometries on a Honda CBR600 F4i gasoline engine typically used to power a Formula SAE car. Also, the effect of adding 180 degree bends to intake runners is evaluated.

Bench fuel injection experiments were performed to investigate the levels of generated fuel vapor immediately after fuel injection into a closed vessel. A synthetic fuel mixture was used consisting of six individual fuel components that are representative of gasoline. Vessel (e.g. port) temperature and pressure were varied, as well as sample location and sample delay time after injection. Vessel vapor space samples were collected and processed in a gas chromatograph in order to quantify the contribution to the fuel vapor by the various fuel components. Companion modeling was performed in order to evaluate two fuel vapor mixture preparation models (Raoult's Law and NIST's SUPERTRAPP). Results indicate that approximately 1/6 to 1/3 of the injected fuel mass is in the vapor form immediately after fuel injection (as a function of temperature). SUPERTRAPP modeling indicates that the injected fuel mass is approximately in equilibrium with 6% of the available air.