was it just me or did anyone else see the Z32 on top gear last night having a burn up with Richard Hammond on his little fold away scooter, hammond says " i nearly had him" yeah right, nearly had the side of the Z32
That is a dump valve, dumping the turbo boost to atmosphere. I really loved them but the whole dump valve thing has become a bit chav for me now Bring on supercharger plenum whining instead.