I myself would suggest you wait until your just about ******** yourself before taking these things. I had an experience similar to yours and BOY OH BOY did I wish I could've died at that very moment. Best of luck with your endeavors and remember to STAY AWAY from your "FRIENDS" until your MUCH STRONGER. (trust me on this one)
I was taking 30+ pills/daily of 50 mg tramadol for about 2 yrs (started with a low dose and quickly tolerated) and was then switched to Subutex. I've been taking the Subs for 1 yr + and I'm doing great. Now coming down in dosage. I did have 2 relapses - so I have experience switching btw the subs and short-acting opiates and back to the subs (which is the worst idea ever.) Regardless, my best advice would be to do what your body is telling you.
'Technically' 24 hrs after a short-acting opiate like the vic, you should be good to go -- but I'd depend more on how I'm feeling to determine this. The general rule of thumb is that you need to be in at least 'moderate' w/d to start the sub. I know from experience (at least for me) -- this does not mean the minute I get restless & sweaty I pop a sub. I wait until I am feeling good and SICK - I mean the anxiety, restless energy, crawling skin - you know, the works.
I HAVE taken sub too early (It was 32 hrs after methadone, which is a long-acting opiate) When I look back on it, I was feeling crappy, but not that bad. I went into the dreaded 'Precipitated Withdrawal' which I would not wish on my worst enemy- most painful thing I've ever felt. I don't mean that to scare you --- but you know your body best. And if you've had an opiate habit, you know what pretty bad w/d feels like. -- that's the right time to do the sub induction.
Obvs, the BEST thing to do would be to take the first dose at your drs office. If you did this, he/she would rate the severity of your symptoms w/the COWS scale. Once you were to a certain level of w/d intensity on the COWS scale, you'd start the sub (try half of the rx'ed dose at first) It doesn't always happen this way, so if you are alone -- do an internet search for COWS scale/score and you can take the test for yourself! Good luck to you and feel free to PM me w/any Q's!