CamSoda -- the folks behind the live porn show -- replaced Farrah with the model who we're told promises to be way more XXX than the "Teen Mom" star. How much more? Thirsty fans who pony up some coin will control the level on her vibrator.

Pretty intense considering this will be Carmen's first ever nude show ... which is slated to go down on December 15 at 10 PM ET. There's gonna be a short, free preview but fans gotta pay to watch more.

The shows have been insanely popular. As we reported ... Farrah's first show was such a hit, servers crashed because they couldn't handle the traffic. Farrah's Halloween encore promised even more viewers ... but she bailed.

And from the look of things, Carmen's gonna be quite the load ... for those servers.