In a small bowl, combine steak sauce, thyme, black pepper and cayenne pepper.
Sprinkle steaks on both sides with salt. Spoon about 2 teaspoons steak sauce mixture over one side of each steak.
Place steaks, sauce side down, on grill over medium, ash-covered coals. Grill, covered, over medium heat for 6 minutes. Brush steaks with remaining sauce, and turn over. Continue to grill until steaks reach 145°F on an internal meat thermometer for medium doneness. Let stand 5 minutes before slicing.