To spin an m90 to 14 000 rpm you'll need a drive ratio of 14/6= 2.3
Which is outside of the m90's efficiency range. (even eaton recommends a larger/better power adder at this point)
Thus knowing how much it flows would only be beneficial if you desired to calculate the precise theoretical improvement from changing power adders.
And bench building motors only works when you know everything from your cylinder head flow numbers to the volumetric efficiency of your motor.
Does it make sense why this thread was a terrible approach to your desired effect?
From the following chart, I'd estimate to be around 690 CFM.
http://www.eaton.com/ecm/groups/publ.../ct_128485.gif