08 This really nifty piece of engineering is what allows you to set the point at which the outboard bodies begin to open. Bruce calls it a progressive spring slider. The linkage attachment-stud is held all the way to the right by an internal spring from idle to WOT for the center throttle body. The spring is stiff enough so that it doesn’t allow any movement until the center throttle body reaches WOT. Once WOT is achieved on the center throttle body, the spring will begin to compress, allowing enough additional cable travel to completely pull open the outer throttles. Note that the stud has moved to the left in the slot.