I've been trying to answer the same question on how to process SFX in XTOL. Ilford has just published a Product Data Guide (1999) with processing recommendations:(posted 9077 days ago)EI200 @20C: 10 mins stock, 14.4 mins 1+1, 18.5 mins 1+2 EI400 @20C: 12.5 mins stock, 17.5 mins 1+1, 21.5 mins 1+2