Dana,
There is no set time on suboxone induction. Everyone is different. Here is the deal with sub. It latches on to the same receptors as oxy. But it only partially activates them where as oxy and hydro FULLY activate them. You need to be at a point where the remaining activity from hydro for oxy is below the level of opiate activity that buprinorphine can provide.
Think if it this way. Your brain is a car. Let's say oxy is a driver. When oxy drives it punches the gas and takes you to 100mph. But it is short acting. Oxy lets off the gas and the car starts to slowly slow down. In an hour you are at 90. 2 hours 80. 4 hours 70. As the speed gets slower and slower you start to feel withdrawal. First it starts with cravings then as the car gets slower and slower more withdrawals. When the car reaches stop that is your max withdrawal point
Now. Suboxone is another driver. Sub drives the car at 30mph only. It can not go faster. If you take suboxone when your car is going 70. Suboxone will SLAM on the brakes and take you from 70 to 30 in seconds. So instead of gradually building up your withdrawal you are hit with it instantly. That is precipitated withdrawal..
The idea is to wait until your car is traveling at 30mph or less. Ideally I of you are traveling at 25mph and suboxone starts to drive you will increase your speed (opiate activity) and your brain will be satisfied and your withdrawal stop.
The BIG issue. Everyone's car goes from 100mph down to 30 using a different amount of time.
Google COWS for opiate withdrawal. A lot of people say get to 26. When I induced at 23 hours I was not at a 26. But I was fine. I think people suggest 26 to be VERY VERY sure you won't go into precip WD. No one wants that.
Hope this helps.