I like a pre-pump activation for several reasons:
- It pulls nutrients into the muscle you will target with the heavy work
- It sensitizes that muscle to being activated
- It creates some pre-fatigue that will help get the fast twitch fibers recruited sooner un the big sets
- It increases the awareness of that muscle prior to training it heavy
That having been said you do not want to do so much pump work that it hurts your performance. Ramping to a top weight for 8 might not be the best solution. All you need to to create a maximum pump with as little work as possible. Which is why I like to use slow tempos, constant tension, hard squeezes and a combination of full and partial reps in only one set to get the work done... basically design something that will get the target muscle fully blow in one work set. Prior to it do 1-2 preparation sets to get ready and select the proper weight.