Make hard drive stepper motor run 7200 rpm
In order to run BLDC motor efficiently you need to know rotor position in relation to the winding(s). For sensored motor you will read sensors, for sensorless ( like this one ) you'd have to somehow read back EMF from the non-energized winding. The open-loop drive is very slow and you won't get any torque.

To know more about BLDC drive read Microchip appnote AN885.

BTW, you should've saved the controller to which this motor was initially attached; it can be used "off label" -> http://mightyohm.com/blog/2009/08/diamond-chop-saw-part-2/