Combining too many programs (a powerlifting program, a sprint program, etc.) will yield crappy results, esp. if you do too much volume in any particular element. A lot of people have better success with sprints/weights/plyos 2x a week instead of 3x a week. I have noticed that if you are motivated and spend a lot of time in the weightroom you are probably going to end up overtrained if you are doing much else besides lifting.
I also wouldn't really look at powerlifting training if you are trying to get faster on the track. There is interesting stuff and good stuff, but the volume is simply too high if you are doing anything except lifting.
Powerlifting volume is not high. Typically, powerlifters get in and out of the gym much quick than bodybuilders because the volume is much, much lower. Lifting set or 8 reps will make a novice stronger, but not do much for an experienced lifter. Powerlifting and or Olympic lifting is ideal for sprinting, because the goal in the gym is to 1)increase limit strength, and 2) increase explosive strength. Getting stronger usually results in better acceleration and better Max V, as long as the increases are not accompanied by too much bodyweight gain. Lifting casually, i.e. just a few general exercises at lower intensities will not improve strength as fast.