This is the particular Rotrex Supercharger that AMC Racing is using in order to set up the Ultra race crafts. This C38-91 Rotrex is the main unit though there are lots of other parts that are used to the powerful recipe. AMC Racing has made watercooled the oil cooler (of the Supercharger) in order to cool it faster. Whoever is interested on a different than the usual- Ultra kits may seek for more info in Japan.
