pack a wallop is to provide a burst of energy, power, or excitement.
Also to pack a punch.
I put a special kind of gasoline in my car because I thought it would pack a wallop. It didn't.
powerful sex skills of a female, ability to make 'short work' of the male! -humbling of the most cocky 'stud'
cheryl really packed a wallop with the gear she possessed! she left john in a spent, babbling heap crying for his mama!
the two salivated and speculated (great phrase!) that judy could pack a wallop!
jane's sex skills didn't quite pack such a wallop when she was 'doing' a woman!
rosanna ground the poison out of him with vigor! she packed quite a wallop!