yeah it starts to open but doesnt come close to opening all the way. the secondary does not rely on signal is relys on primary throttle posision and engine vacuum. if you dont have your foot the the floor the secondaries cannot open because of machanical restriction. wot will not open till minimum vacuum pressure is in engine with given rpm
starts to open fully opened
yellow short spring- 1620 5680
yellow 1635 5750
purple 1915 6950
plain (std. spring) 2240 8760
brown 2710 8750
black 2720 does no fully open at maximum air flow
would you like me to take a picture of the holley instruction sheet where i got this from?