BOV - Blow Of Valve
SSQV - Super Sound Quality Valve (Type/Model of BOV)
A blow-off valve is mounted in the intake plumbing between the
turbocharger compressor and the throttle plate. The blow-off valve is a
second safety measure against the turbocharger over-boosting and damaging
the engine.
The blow-off valve is more commonly used to keep the turbocharger spinning
when the throttle plate is suddenly closed. When the turbocharger is
generating maximum boost pressure at full throttle and then the throttle
is suddenly closed, compressed air coming from the compressor slams
against the throttle, generating extremely high pressures that travel
backwards to the compressor stopping the compressor from spinning. When
the throttle plate is again opened, the engine must spool the turbocharger
shaft again. The effects of this high pressure can also be very damaging
to the turbocharger.
Have 2 Type of BOV:
i. Open Atmospheric Type : That have sound out like kepishh/kaa ching/ keenn chingg!!
ii. Closed Type : Dont have sound. Return air/gas to inlet.
Hope can help. :)