How to make a fast soap box derbyHow to make a fast soap box derbyAmerican Soap Box Derby . The specific features, conditions and setups that make a SBD car go fast change with . you would make a great soap box . . . . . The Soap Box Derby is a well-known race for kids that's been around since 1933. a) Potential Energy (PE) [Gravitational Potential Energy for Soap Box Derby . I must begin this document with a disclaimer: My experience building fast derby cars is limited. . . . . . great accomp... more