The high from IV'd buprenorphine is almost indistinguishable from the "plateau stage" of a heroin high IMO. There's no rush but properly-dosed it's undoubtedly the most economical of any opioid you could possibly abuse that way.
Also, less is more with buprenorphine. Dividing one suboxone strip into four pieces for an injection preparation, that's way way too much. You should be aiming for a dose measurable in the micrograms...that's how injection-ready buprenorphine is doled out, buprenorphine is a very potent narcotic opioid and if you're attempting to inject a dose that would get a recreational drug user high by taking it orally, you're taking too much. You should be aiming for a dose that'll dissolve (seemingly) completely in about 30 units of water.
Note: the above information is for entertainment purposes only, don't inject buprenorphine, drugs are bad mmkay, etc.