AEROFLOW 11 PSI BLOW OFF VALVESPRING use with 64-4050 new

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.