Try this day at your own risk, the first exercise is sure to get your shoulders so pumped the remaining exercises will be difficult to do. Timed exercises have been implemented before but never with any significant amount of weight, it was more or less, "barbell conditioning".
Shoulders:
Timed overhead DB press – Pick a weight that you can do for 20 reps. Do 1 rep every 6 seconds and shoot for 2 minutes each set. Do a total of 3 sets and rest a few minutes between. No need to lock out at the top but do NOT bring the weights off your shoulders. This sucks so push through. 20lbs
Face pulls – 3x20: 40
Chain Lateral raise – 3x12, then 1x20, even if partial reps: 1 chain
Machine shoulder press – 4x15, 12, 10, 8 (drop set this last set): 35-45-55-65(55-45-35)
Pushups with feet raised – Set a bar in the bottom of the power rack. Raise your feet up on a box. Do sets of 8. Do sets until you can’t complete 8 reps. (so do 8, rest a minute or so, do another 8, rest, etc. it doesn’t really matter how long you rest. Obviously, if you take longer rest, you’ll get more sets in)
DB curls – 4x8: 25 strict and with full extension at the bottom, good squeeze at the top
Supersetted with
overhead rope extensions – 4x12:80