For my previous post, I just wrote in general because both here ( in FT ) and elsewhere, the people who I talked with wasn't aware that the USA doesn't have any COVID test requirements for entry.

If we return to your case, allow at least 5-8 hours to be safe and don't forget that you might need a e-visa to enter Turkey depending on your nationality as the COVID test center is landside and you would need to clear passport control and immigration to go there.