Getting Up to Speed

Right now we're facing a problem getting players to go at game speed. We've taught the techniques and blocking assignments to take care of the problem of sitting back because they're not sure where to go. We're still slow off the ball and our initial contact is soft, much less sustaining that contact. We did have a good object lesson in practice today when a smaller but aggressive player moved a bigger, athletic, but less aggressive player out of the hole. Playing at game speed is not coming natural to this group. We've scrimmaged with a late whistle to get everybody to stay with the play. We ran wedge after wedge today versus 15 defenders (yes 15) just to promote hard nosed running and sustained blocking at the point of attack. The offense at least started to move the ball.
Another problem is getting backs to cut up field on the power plays at the 8/9 hole. We've had the runner run into the back of the B kicking out on the OLB, or try to run around the outside of the kick out block. Today in practice we ran full speed 11 on 11 plays with me standing at the point to cut upfield. Its kind of interesting to watch the play from right in the middle of it.
Any ideas would be great.