The HKS Variable Boost Controller (VBC) is a boost control system utilizing a pneumatic relief or regulator valve, depending on the application. These VBCs are designed to work with single or dual port actuator wastegates. While many manufacturers offer only a "one size fits all," HKS vehicle specific VBCs includes all components necessary for the installation of an effective boost control system. Each vehicle has specific requirements that necessitate the inclusion of such items as adjustable pop-off valves and T-fittings which are included in all of the comprehensive VBC systems. VBC systems are also available as general application systems.