In small bowl, combine salt, pepper, garlic powder, paprika, and chili powder. STIR
Drizzle 1 tsp of liquid smoke over each rack of ribs.
Divide spice mix between both racks and rub all over ribs (front and back)
Divide brown sugar between both racks and rub all over.
Lay out two long sheets of foil and place a rack on each. Place another foil over top. Tightly roll edges. Place on baking sheet.
Cook @300° for 4 hrs. (until meat pulls away from bone)
While the ribs cook mix up the three ingredients for the BBQ sauce. 10. Remove racks from foil, Place on cooking sheet, fleshy side up and spread BBQ sauce on top. Broil for 3-5 min.