Gee, Ernest, I don't know.

But, perhaps we can get a handle on it starting with  F = m*a.

lets take one cubic foot of air and assume no losses in accelerating it from 0 to 150 Mph.  Now we need a time interval and it has to be around 1 rpm (one revolution of the blades) so that is approx 60/7000 = 0.00857 sec/rev. Since we want 600 cfm of air to flow at 150 mph we need to have the blower flow 600/7000 = 0.857 CF per revolution.  0.857 * 7000 = 600 CFM - checks!

At 7000 rpm the e shaft needs 0.00857 sec per rev.  So  we want to accelerate 0.857 CF of air from zero to 150 mph in 0.00857 seconds.

A cubic foot of air has a mass of 0.0765 lbs at sea level.  So M = 0.0765 lbs.  We need to accelerate it to 150 mph or 220 ft/sec velocity in 0.0086 seconds.  So dV/dt = A = 200 ft/sec/0.0086 sec = 25,666 ft/sec^2 or 25666/32 = 802 Gs acceleration.  Therefore F = m*a = 0.0765 * 25666 =  1963.5 lbf/sec = 1963.5*0.001818 = 3.56 HP  Since we continuously need to accelerate that amount of air it would appear that not counting for any losses that you would need approx 3.56 HP or approx 1/2 of the amount your increase air supply might contribute to power increase in the engine.