Do you have an auto or a manual? I imagine the auto really takes away from the speed.
Since you have an SES, do you have the 17'' wheels? It's my understanding that the 17's are heavier and the tire is taller. The SES already has shorter gearing, try to throw on a lighter and shorter set of OEM 15s ... that should get you a bit.
Try to keep it on the track or the strip; street racing doesn't end well.
2011 Focus SE 5 Speed.