Bypass valve??

[jt98boost]

I just installed a new raptor bypass valve to replace the bosch plastic one that comes with the vortech kit, my question is that I can apply a vacume and see the bosch one open and close with little vacume, but on the new bypass I can apply the same vacume and it will not open. Do these have to have vacume to open or does the boost supposed to open them?? I had a surging problem and wonder if the plastic bosh bypass was opening too soon?? I also wonder if this new bypass will even open since the vacume that I applied to it did not make it open, anyone got any ideas