Go-karts are a popular form of recreation and competition. Go-karts are those vehicles having four wheels, a frame, and an open cockpit but lack a suspension system. While go-karts started with air-cooled engines, high-performance go-karts have progressed to liquid-cooled engines that utilize a liquid-to-air heat exchanger to remove the heat from the liquid. This liquid cooled configuration allows the engines to achieve a higher performance without overheating.
The heat exchangers, such as a radiator, receive airflow as the go-kart travels, and the heat of the liquid is transferred through the heat exchanger to the flowing air. Typically, go-karts have a side-mounted heat exchanger that is exposed to the surroundings as go-karts are usually limited in size, and the side mount is a convenient place to position the heat exchanger. Thus, air is directed at and around the side-mounted heat exchanger to provide the cooling. However, this conventional side-mounted heat exchanger is an aerodynamically inefficient design.
The aerodynamic inefficiency of this side-mounted heat exchanger occurs because the heat exchanger creates drag by providing resistance to the air passing by the go-kart. Additionally, the side-mounted and exposed position of the radiator provides only a limited amount of air pressure on the front surface of the radiator. Thus, the heat exchanger must not be dense so that air with only limited pressure can be satisfactorily forced through, but must be relatively large to achieve the necessary amount of cooling due to the lack of density. The relatively large size of the heat exchanger results in an overly large amount of drag. This drag created by the heat exchanger negatively impacts the performance, namely acceleration and top speed of the go-kart and therefore, is an undesirable result.
Attempts have been made to improve upon the side-mounted heat exchanger. For example, heat exchangers have been mounted on the rear of the go-kart. However, a rear-mounted heat exchanger also generates an unacceptable amount of drag. This unacceptable amount of drag occurs both because of the blunt, non-aerodynamic shape created by the heat exchanger at the rear of the go-kart and also because the heat exchanger must be relatively large with a low density to account for the lack of air pressure developed on the front side of the heat exchanger.
Attempts have also been made to increase the cooling efficiency of the rear-mounted heat exchanger. A plenum has been placed on the front-side of the rear-mounted heat exchanger to channel air since the rear-mounted heat exchanger is behind the driver seat and does not otherwise receive a freestream of airflow. However, these attempts have failed to properly match the plenum to the heat exchanger to optimize static air pressure on the front of the heat exchanger such that the rear-mounted heat exchanger must continue to be large with a relatively low fin density. Furthermore, these attempts have failed to address the drag associated with the blunt shape at the rear of the go-kart due to the presence of the heat exchanger. Thus, the drag associated with a heat exchanger for a go-kart continues to negatively impact performance.