Rear disk wheel on a reclined lowracer *already* serve as a kind of rear fairing (splitter plate), and you'll need a VERY effective design to top it.
Here is a project for a reclined lowracer:
http://www.recumbents.com/wisil/misc/nocom/tb/default.htm
Notice how it turned out 'not worth it' in the end. OTOH, it did *work* (just not enough to warrant using it), and can be a good *cargo* box for a touring setup.
And btw, on a less extreme (titanium, very flexy too) lowracer I've managed to cruise at 40kmh quite easily on about 230 or so watts. They are VERY aero, but it comes with a price of low vision/visibility.
Here is a project for a reclined lowracer:
http://www.recumbents.com/wisil/misc/nocom/tb/default.htm
Notice how it turned out 'not worth it' in the end. OTOH, it did *work* (just not enough to warrant using it), and can be a good *cargo* box for a touring setup.
And btw, on a less extreme (titanium, very flexy too) lowracer I've managed to cruise at 40kmh quite easily on about 230 or so watts. They are VERY aero, but it comes with a price of low vision/visibility.