If you can't get your hands on some caffeine pills, that might help with energy and focus. If you can get your hands on some of that energy spray, that works too. Never used it for anything lifting related, but me and my friends used to take that stuff for the fun of it and we'd be jacked up for about an hour afterwards. Other than that, make sure you do your warmups well, and avoid static stretching right before your event. Research shows that static stretching reduces strength for a time afterwards. Try some dynamic stretches for the chest, deltoids, and triceps.
If the event is aimed at total reps completed, I still wouldn't throw the weight as fast as possible, as you set yourself up for possible injury. I would push the weight at a reasonable pace, however, because your goal is total reps, and nothing more. Don't drop the weight on the negative, but lower it as fast as you can while maintaining control.
That's about all I can think of! Good luck, man!