Originally Posted by onovakind67
Edelbrock describes the secondary operation like this:
A mechanical secondary air velocity valve in Performer Series carbs senses air-flow according to demand and automatically regulates a smooth transition from part throttle to wide-open throttle.
These carbs have mechanical secondary throttles that should open wide when you rotate the linkage all the way.
I guess you all are trying to answer my question but I don't have a Holley, nor do I a have a Performer. I have a Elderbrock Square Bore Thunder carb. The secondaries DO NOT open more than 1/8th inch when the throttle is wide open. I thought someone here with experiance on a Thunder carb could offer me an answer. From the answers above, I now know what a Holley and a Performer card do. Anybody know anything about a Thunder Carb?