Preheat oven to 500°F with rack in lowest position.

If using turkey wings, halve at joints with a cleaver or large knife, then crack wing bones in several places with back of cleaver or knife. (Do not crack bones if using other parts.) 

Pat turkey dry. Roast turkey parts, skin sides down, in dry roasting pan, turning once, until browned well, about 1 hour. 

Transfer to an 8-quart stockpot using tongs, reserving fat in roasting pan.

Add onions, celery, and carrots to fat in pan and roast, stirring halfway through roasting, until golden, 25 to 30 minutes. 

Add vegetables to turkey in stockpot.

Straddle roasting pan across 2 burners, then add 2 cups water and deglaze by boiling, stirring and scraping up brown bits, 1 minute. 

Add deglazing liquid to turkey and vegetables in stockpot, then add remaining 3 1/2 quarts water along with remaining ingredients and 1 teaspoon salt. 

Bring to a boil, then reduce heat and gently simmer, uncovered, 3 hours.

Strain stock through a large fine-mesh sieve into a large bowl, discarding solids. (You will have about 10 cups stock.) 

If using immediately, let stand until fat rises to top, 1 to 2 minutes, then skim off and discard fat.

 If not, chill, uncovered, until cool, then covered, before skimming fat (it will be easier to remove when cool or cold).