This fall, James Madison will make its FBS debut in the Sun Belt Conference. With the right timing, the right coach and an instilled culture of excellence, the Dukes are doing so knowing they can be one of the bigger FCS-to-FBS success stories of the modern era.  Sitting in the western part of Virginia in the Shenandoah Valley, the Harrisonburg-based campus and its athletic department have seen rapid growth in the 21st century. The Dukes won the FCS (then Division I-AA) national championship in 2004 with head coach Mickey Matthews, and that success helped kick-start an investment in football that paid off with seven more conference championships, three more FCS…