I disagree mack, admittedly I haven't read the studies personally, but anything that speaks or asks about "rape fantasies" to me is a fallacy; there is no such thing as a "rape fantasy" from the position of the victim, it is an oxymoron.
I think it's a problem of language and semantics, when thinking of the (apparently common) "rape fantasy", nobody actually fantasises about having something happen to them that they don't want to happen. So what are they really fantasising about - someone else being in total control, the idea of a stranger finding them so irresistibly sexy, sex which moves fast with no apology, sex which is rough and possibly painful, sex which is unexpected, sex in an unusual location, sex which you aren't expected to/don't have to pretend to enjoy (that one's pretty fucked up but I'm sure it's in there)
I don't see, if rape porn was banned, that there couldn't still be porn which caters to all of the above categories (with the possible exception of the last) but with consent. Of course this relies on a magical world of porn where consent is open and transparent and honest which currently doesn't exist, but... I think that the actual "kink" behind what we tend to think of as a "rape fantasy" could actually be expressed in loads of other, way more healthy ways, without also satisfying the very real fantasies of a real life rapist. I don't think those fantasies are valid or healthy, any more than somebody who fantasises about child abuse or cannibalism. And I don't think we should be normalising/enabling them because there is this perception that women have "rape fantasies" whereas actually they quite like the idea of many other things which are nothing to do with rape.