Easy to Install and Setup, Turbosmart Supersonic BOV. Preferred venting solution for serious street tuners and racers. Significant flow and an even bigger sound. Easy to Install and Setup, Turbosmart Supersonic BOV. Preferred venting solution for serious street tuners and racers. Big flow and even bigger sound. Behind every Turbosmart product stands a long and rich racing history. While a majority of Turbosmart products are used on street cars, their design and testing procedure is identical to the high-end purpose-made racing products. Before reaching the consumer, Turbosmart products are subjected to a range of tests performed in the most demanding environment, the race track. Subaru Forester XT 2006-2007; Subaru WRX 2001-2007; Subaru WRX STI 2001+