Torsion shear stress using patran free-body tool

[gantovnik]

I have non-symmetrical beam cross-section, where centroid does not coincide with shear center. I extracted free-body forces and moments at the centroid: Fx,Fy,Fz,Mx,My,Mz, where Mz is torsion moment. I want to calculate torsion shear stress by the formula: fs=T*n/J, where J=(1/3)*sum^n_{i=1}b_i t^3_i, n=number of segments. The question is which torsional moment should I use 1) Mz from free-body tool or 2) Mz+Fx*dy+Fy*dx, where dx and dy are distances between centroid and shear center in x and y directions, respectively. Thank you!