I recently bought a new switchback xt and I am looking at getting more speed out of it. I had it chronied right at 250fps. I would like to add some speed, but how can I do that rather inexpensively? I shoot Gold tip 5575 arrows with 90 grain muzzy broadheads, and 4in feathers. Would changing the fletching and/or broadheads help any? What about the 2in blazers?