I used a narrow grip for several months following shoulder surgery. My tri's were growing well, but not my chest. As soon as I went wider, my chest showed noticable improvements.
I really don't go that wide. Different bars had rings that vary, but generally I'm just outside the first ring. When the bar's on my chest, my elbows are still less than 90 degrees.
If I flair my elbows, it helps. Or should I just stay narrow?