From what I've experienced it takes a whole twenty-four hours to feel about half of the normal effects of opiates after ingesting Suboxone and roughly forty-eight to sixty hours to start feeling the full effects. However seeing that you administered it intravenously I would imagine the wait to be slightly shorter in length, I would also say it depends on what opiate you are planning on using and how you plan to administer it. I would give it a whole seventy-two hours to be safe (if you can last that long without feeling like complete garbage).
Good luck and be safe.