You can't adjust a torsion spring. The spring is sized to the weight of the door by altering the wire size, the diameter of the spring, and the number of coils. The spring gets wound 1/8 to 1/4 turn beyond 1 full turn per foot of door height to balance the door. That is a small door, adding a strut or perforated angle to the top rail won't add enough weight to make a difference to the spring or the opener. Add a strut per panel and the door will no longer balance but the opener will likely still work fine, though the plastic gears will have a slightly shorter service life. Greg, there is a bracket for doors that don't have a center stile, but it doesn't work on doors with windows in the top panel. [] Mike is right about the down force, it's too high, and the bottom limit is probably wrong too. With a torsion spring that opener can be anywhere but above a vertical stile is preferable. I have a client that has one opener centered between two doors, it's been opening both for over a decade.