SSQV Blowoff Valve (Super Sequential Blowoff Valve) The HKS Super Sequential Blow-Off Valve (SSQV) is a dual stage pull-type relief valve. Unlike typical push type blow-off valves, the SSQV will not leak under any level of boost because the boost pressure in chamber "C" keeps the valve closed against its seat (Diagram 1). The SSQV releases excess boost when there is a pressure alteration in chambers "A & B", not by the rate of boost pressure or vacuum in the line. This ensures a quick valve response and complete closure during idle. Many competitors use a push-type blow-off valve design with a large valve to accommodate high boost / high horsepower applications. These large valves react slowly and require high pressure to open, and are not able to activate and prevent compressor surge at light-load conditions. On the other hand, smaller, fast reacting push-type valves do not discharge the airflow capacity required for high horsepower applications and tend to slowly open and leak as boost pressure overpowers the spring. For maximum performance, the HKS SSQV incorporates both a small primary valve for ultra quick activation, and a larger secondary valve for additional discharge capacity. The SSQV is engineered to initially open the small primary valve at light throttle and load conditions (Diagram 2), then sequentially opens the secondary valve for additional relief capacity under high boost and load conditions (Diagram 3). The SSQV is constructed of polished billet aluminum, which ensures long-term durability and a high luster look. The mounting base utilizes a circular mounting flange that combines with a C-clip snap ring and O-ring gasket to insure an excellent seal. The triple-fin discharge port design produces a powerful, unique and aggressive blow-off sound. The HKS SSQV is available in vehicle specific kits or as a universal unit for custom applications. Vehicle specific HKS SSQV kits come complete with all mounting flanges, brackets, and miscellaneous hardware for an easy installation. For Universal SSQV applications, weld-on flanges are available in steel or aluminum for custom installation.