In a small bowl combine chili powder, sugar, salt, coffee, and black pepper. Pat meat dry and rub seasoning over steaks. Let stand for 30 minutes.
Remove slides from Gravity Series grill. Open charcoal hopper doors. Pour in charcoal if needed and fill hopper. Light. Turn on and set temperature to 450˚F.
Grill with lid closed for 3-5 minutes on each side or until it has reached desired doneness. Remove from grill and let stand for 5 minutes.
Slice across the grain into thin tender strips and serve with fresh fruit salsa and lime wedges.