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The problems which arise during the design of a motorcycle, may affect the proper functioning of the vehicle, and ride comfort. This type of problem is particularly found in sport where mechanical components which can cause malfunctioning should, be replaced quickly within a very limited time. This work is an investigation of the swingarm component. The aim is to link objective data such as stiffness and natural frequencies (derived through the application of scientific method) with subjective information such as handling and comfort perceived by professional riders. The testers were two riders of the 2008 World SuperBike Championship. They were chosen to represent two kinds of driving behaviors: one of them had a affable riding attitude, whereas, the second was more aggressive. Three motorcycle swingarms used in the 2008 World SuperBike Championship, were mechanically characterized: FEM and experimental investigations were performed.

Lean operation of spark ignition engines is a promising strategy for increasing thermal efficiency and minimize emissions. Variability on the other hand is one of the main shortcomings in these conditions. In this context, the present study looks at the interaction between the spark produced by a J-type plug and the surrounding fluid flow. A combined experimental and numerical approach was implemented so as to provide insight into the phenomena related to the ignition process. A sweep of cross-flow velocity of air was performed on a dedicated test rig that allowed accurate control of the volumetric flow and pressure. This last parameter was varied from ambient to 10 bar, so as to investigate conditions closer to real-world engine applications. Optical diagnostics were applied for better characterization of the arc in different operating conditions. The spatial and temporal evolution of the arc was visualized with high-speed camera to estimate the length, width and stretching.

It has been proved that Radio Frequency Corona, among other innovative ignition systems, is able to stabilize combustion and to extend the engine operating range in lean conditions, with respect to conventional spark igniters. This paper reports on a sensitivity analysis on the combustion behavior for different values of Corona electric control parameters (supply voltage and discharge duration). Combustion analysis has been carried out on a single cylinder PFI gasoline-fueled optical engine, by means of both indicating measurements and imaging. A high-speed camera has been used to record the natural luminosity of premixed flames and the obtained images have been synchronized with corresponding indicating acquisition data. Imaging tools allowed to observe and measure the early flame development, providing information which are not obtainable by a pressure-based indicating system.