Lol, you can make your punches faster by whacking a heavy bag as fast as you can w/ 16 oz gloves all the time. You'll see how fast you're punching barehanded or w/ an MMA glove after that.
When you can punch w/ a 16 oz glove as if you're punching barehanded, then you've become at least faster but only relative to yourself. You have to spar in order to see if you can use that speed practically.
However, fast is nothing if you don't have accuracy, timing and strength in that order of importance.