I have done 140 in the standing 1/2 mile at the Carrabelle Speed Festival.
The max based on the Manual gear ratio you may see is maybe 205mph based on the 285/35YR19 Rear Tire.
Gear Ratios (Manual)
1st 3.794
2nd 2.324
3rd 1.624
4th 1.271
5th 1.000
6th 0.794
Reverse 3.446
Final Drive 3.692
Now that in mind you have to bring in the drag coefficient if the Z @ .30 . With that said, I would guess someplace around 177 to 180mph Max.
So Using vehicle Speed of 205 MPH it takes 335.23 HP to overcome air drag.
Rolling resistance is 23.45. (Not 100% sure of)
For a total of 358.68 HP to run 205 MPH
This info is base off the Nismo.
All this take about the 370z being drag limited to 160 is BS. I have been over 160mph in mine on the track. It's just plan BS that it's drag limited to 160mph.