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Intake tuning is a widely recognized method for optimizing the performance of a naturally aspirated engine for motorsports applications. Wave resonance and Helmholtz theories are useful for predicting the impact of intake runner length on engine performance. However, there is very little information in the literature regarding the effects of intake plenum volume. The goal of this study was to determine the effects of intake plenum volume on engine performance for a restricted naturally aspirated engine for Formula SAE (FSAE) vehicle use. Testing was conducted on a four cylinder 600 cc motorcycle engine fitted with a 20 mm restrictor in compliance with FSAE competition rules. Plenum sizes were varied from 2 to 10 times engine displacement (1.2 to 6.0 L) and engine speeds were varied from 3,000 to 12,500 RPM. Performance metrics including volumetric efficiency, torque and power were recorded at steady state conditions.

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.

Due to their high specific stiffness and strength, carbon-epoxy composites have become the predominant structural material at the highest levels of international motorsport and are also gaining widespread popularity in collegiate design competitions. Formula SAE is one such event where college students design, build, and race a small, formula-style race car in an autocross environment. The use of composite materials in the structure of these vehicles provides a competitive advantage through weight reduction. Undergraduate students often face a steep learning curve when dealing with composite materials, however, as they have had little exposure to the design, analysis, and fabrication processes of composite structures. By outlining the design and testing of a carbon-epoxy A-arm for a Formula SAE vehicle, this paper will serve as an introduction to the unique benefits and challenges associated with composite motorsports structures.

A carbon-fiber-reinforced plastic (CFRP) monocoque racecar frame was designed and constructed by students for the 2012 Formula SAE (FSAE) collegiate design series competition. FSAE rules require that the monocoque frame have strength equal to or greater than the traditional steel space frames that they replace. The rules also specify minimum values for perimeter shear strength, main roll hoop attachment strength and driver harness attachment (pullout) strength. Overcoming limitations imposed by locally available finite element analysis tools, a variety of tests were devised to determine required laminate thicknesses and layup orientations. These included perimeter shear tests, pin shear tests, three-point bend tests and tensile tests. Based on the results of these tests, a sandwich construction using composite skins fabricated from carbon/epoxy prepreg and aluminum honeycomb core was selected.

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.