What was Billy working on in Zeo?

[PRangerX]

During the Gold Ranger Saga, there were numerous times Billy was teased to be the Gold Ranger. He always seemed to not be around when the Gold Ranger fought. And spoke about this secret project that he was working on. We never found out what that was. Some fans seem to think that it was the Turbo Powers. But thats not neccessarly the case. Since the Turbo Rangers aparently design the Turbo Powers in the Turbo Movie. But I suppose its possible that they just finished Billy's work. Perhaps he was working on something else that we just never saw on screen.