HKS Super SQV (Super Sequential Blow Off Valve) uses a unique sequential valve structure and a differential pressure control system, which allows for a broad operation range from low boost to high boost.
a bov or blow off valve is just another name for a dump valve! I rem i had my glanza parked outside the house one day, i was upstairs and i heard the lad that lived mext door talking to his friends. They were talking about the car, one said oh its turbo cos it has a dump valve, the other said whats that, the first fella says oh thats the thing that sucks in the air and makes noise lol
a bov recirculates into the intake.