AEROFLOW 6 PSI BLOW OFF VALVE SPRING USE WITH -8 to -12" HG

These replacement blow of valve springs are specificallydesigned to fit inside the Aeroflow Performance 50mm blowoff valves. Both of our Aeroflow Performance blow off valves feature a 11psi spring from out of the box. If you wish to change this spring, weoffer either a softer 6 psi for turbo setups or a 2 psi spring designed for supercharger options. AF59-2150 Green 2psi (.13BAR) Supercharger Only Spring AF59-2152 Black 6psi (.40BAR) Turbocharger Spring (-8 to -12 in/Hg) AF59-2153 Yellow 6psi (.75BAR) Turbocharger Spring (-18 to -20 in/Hg)