The Racing Bypass Valve Type 34 was specifically designed to replace the 34mm Bosch Bypass Valve used many OEM applications such as Nissan and Mitsubishi.  The plastic Bosch valve is prone to failure when running higher than stock boost levels.  Unlike the OEM valve, the RBV-34 is adjustable, making it ideal for your modified vehicle. This RBV-34, though louder than a stock bypass valve, is not loud compared to an atmosphere BOV.?