Draw a line from bottom of tire through front eye to back of cam, first place to start. Moving up one hole brings instant center toward back of car, one hole down goes past engine a little. Weight bias front to back determines where you want the instant center. Farther back the more the a$$ end moves up till HP goes up, it’s a balancing act till car rotates. The front suspension has a tremendous effect on how it all works together. Theoretically you want entire weight of car on the back tires on launch but not rotating to far back.