Form is the difference between bodybuilding and simply lifting weights. Poor form with too much weight takes the stress off the target muscle; momentum moves the weight, not the muscles. Bodybuilding is accomplished best with strict form, controlled tempo, optimal tension, and total concentration. If muscle size is your number one priority, you must do everything in your power to make the exercise harder, not easier. You must select the path of maximum stimulation - which also happens to be the path of most resistance, effort and pain.
I believe you posted in the wrong section, welcome aboard.