If you are referring to model subs (ww2 vs nuke), then I'm sure you could rig a ww2 sub to run fast. From a drag perspective, though, ww2 will never be as slick as a nuke. If your sub races specified max motor size, then the slicker nuke hull would beat the draggy ww2 hull. btw, one of the reasons real nukes are faster is that they run deeper than the ww2 subs. Deeper water=higher pressure=> less cavitation of the prop.