Super slow z axis (no replies)

I have t8 lead screws hooked up to a belt driven single stepper motor at a 2 to 1 ratio.
So, basically one turn of the stepper motor moves the z axis 4mm.

Using a 200 step count time 16 for microstepping divided by 4, I end up with 800 mm per revolution on my DEFAULT_AXIS_STEPS_PER_UNIT.

This is working, the motor sounds great, but when I am in repetier host and initiate a 10mm move it takes well over a minute. lol

My y and x axis seem to respond to acceleration config stuff in Marlin, but Z is not playing ball.

I am new to this, so I am sure I am missing some critical piece of information. Google was not my friend in this particular case.

BTW, these numbers have been heavily tweaked. Not gonna be my default. But I will show you what I have now in the current Marlin firmware motion stuff.
Z is the one I need help with.

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,800,500} // default steps per unit for Ultimaker
#define DEFAULT_MAX_FEEDRATE {100, 100, 15, 25} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {3000,3000,3000,10000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 3000 // X, Y, Z and E acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 500 // E acceleration in mm/s^2 for retracts
#define DEFAULT_TRAVEL_ACCELERATION 10000 // X, Y, Z acceleration in mm/s^2 for travel (non printing) moves

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK 20.0 // (mm/sec)
#define DEFAULT_ZJERK 2.0 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)