The HKS Super Sequential Valve is a dual stage pull type relief valve, which prevents compressor surge by releasing (either back into the intake stream or into the atmosphere) the compressed air flow that is normally forced backwards into the turbo as the throttle is closed.

Engine performance is increased from quicker turbo spool up as the compressor speed is not reduced by backwards air flow. The life expectancy of the turbo is also increased, as its bearings will not suffer from the impact that is common with compressor surge. For maximum performance the SSQV incorporates a small primary valve for quick activation that opens under light boost and load conditions and a larger secondary valve that opens sequentially to relieve pressure under higher boost and load conditions. The SSQV is constructed from billet aluminium for durability and has a high quality polished finish.