Previous study on the forward pi0 cross-section found that Pythia ver. 6.4 + either tuneA or Perugia0 and <kT>=0.5GeV results in reasonable agreement with the published result.

Fig. 1. Forward pi0 cross-section in Pythia 6.4 tuneA vs. Perugia0, <kT>=0.5 and 1.0GeV

Fig. 2. Perguia0 vs. published FPD results

Based on this, we are considering the following Pythia setup for the full FCS simulation. 

Version: 6.4
Tune: TuneA 
Gaussian width of primordial <kT> = 0.5 GeV  

Limits on p_perp (transverse momentum of 2->2 hard process)
    ckin3=0.0 GeV (might be too low)
    ckin4=-1.0 (no upper limit)

Additional limit for processes that diverges as p_perp -> 0
    ckin56=1.0 GeV