This is something that would be easy to graph with a parametric equation. You can find a parametric equation plotter I made for illustrator here:
I quickly tested with following parameters:
Function:
X: 2.2*(t+3*PI) * sin(t) + 300
Y: 1*(t+3*PI)* cos(t) - 200 + 6/4*PI*t
Range:
Min: 3*PI/4+0.5
Max: PI*6+2*PI/4
Step: PI/8 (or PI/4)

Image 1: Graphing of a suitable parametric equation yields.
You may want to adjust the numeric values of the equation a bit to suit your needs. This is quickly done after all.
For finishing touches. Use the cut tool to cut the shape up and delete segments at overlapping joins.

Image 2: After twaking a bit more Result after making raise a bit bigger (the term 6/4*PI*t).