Blow off valve, you seem em on turbo cars all the time bust almost never on supercharged cars. The recirculator serves a similar purpose but in the stock airbox it sends the excess air back into the intake. With this custom air intake it basically is a BOV.
Completely mad.
'99 C230K, intake and exhaust more on the way.
'86 MKIV Escort RS Turbo, stock for now, chip and more boost on the way
'75 Fiat 124 Spider, koni shocks, bigger carb and drilled/slotted brakes
to tune and hoon the mbz master race.