Pit Stop USA is The Online Motorsports Superstore! DPI Performance Racing Products offers innovative products for the racera DPI was founded by veteran west coast racer Dan Press. Dan was dedicated to developing products that really work and that was the driving force behind the success of DPI. In 2003, DPI was sold to Randy Larsen of Larsen Racing Products. The DPI product line includes DPI Black Gold Differentials, DPI Platinum Track Differentials, DPI Sure Stop I, DPI Sure Stop II, DPI Crossover Tubes and more. We feature DPI Performance Products at low everyday prices!