The Turbo XS High Performance Boost Controller (HPBC) is the right choice for simple accurate and reliable high level boost control. The HPBC has two (2) boost control mechanisms built into it. One is a ball and spring mechanism for large and coarse boost pressure increases and the other is a bleed valve system for precise boost pressure setting. The ball and spring mechanism keeps pressure out of the wastegate until the preset boost level is reached significantly reducing wastegate creep and providing quicker turbo spool up. Boost is adjusted with the simple turn of the screws using the included 2mm hex key.