The Big model originates from a specific requirement dictated by a change to regulations. With the advent of the current kart fairings, which are bulkier than in the past, the area for the installation of the radiator has been deprived of a significant amount of air, which is diverted by the larger nose panels. This is the reason why New-Line Racing has tried to make up for this deficiency by producing a radiator that is more generous in size, not so much in terms of height, but in width.
New Line Big
Tax included.