read all the post of people saying their stockers are leaking...it doesnt leak, it doesnt close 100%, well i guess that could mean the same thing. at part throttle boost if you have an aftermarket intake you can hear it the damn thing hissing, the spring again by design is left weak to counter part throttle boost compressor surge.
I upgraded from my stock bpv the car feels completely different it now holds 16psi till 5300 My DH log shows that at 53-5400 RPM im holding 16psi (15.83) b4 it falls off. Where the stock one was falling off hard way b4. I’m not saying ALL the stock BPV are a POS. I was doubtful at first as well, and thought I wasn’t going to see/feel a difference.
I did a LOT of data logging with the DH in all different gears [stock bpv's boost vs. rpm] MY stock bpv seem to be a little week. I upgraded to the forge and the car HOLDS boost.
Also I went out with a friend last night and he even said without even knowing "what did you do to your car? It feels more aggressive!