Yes, you can. The 944-series cars were generally available outside of the US market without air conditioning. Some performance-oriented owners would like to remove the AC compressor to recover the small amount of horsepower consumed by turning it and by carrying its weight around the track or autocross course.
The only realy issue with removing the compressor, is that it is used to tension the polyrib belt that also drives the alternator. A different "manifold" (bracket) is needed that allows the alternator to pivot so that it now tensions the polyrib belt.
You will need the following parts to convert your car:
quantity part number description 1 944.603.134.01 manifold, 82 - 85/1 models, M8 alternator pivot bolt 1 944.603.134.02 manifold, 85/2-forward models, M10 alternator pivot bolt 1 N.010.480.3 bolt, M10 x 80 mm. 4 N.010.47.7 bolt, M10 x 7 mm. 1 951.603.115.02 alternator shroud 1 9188.8.131.52 polyrib belt, K5 x 736 mm., 82 - 85/1 models 1 999.192.290.50 polyrib belt, K6 x 720 mm., 85/2-forward models
The procedure is straightforward. The turnbuckle previously used to tension the polyrib belt via the AC compressor is relocated to instead connect to the alternator. You may need to change the fasteners on the turnbuckle eyebolts to suit the new application.
Because it is relocated, the shroud that mates the air ducting to the rear of alternator is different. You will also have to shorten the duct hose a bit.
Gerry Burger has written up the procedure for this change in the September 2006 issue of Excellence.
Some suggestions from the list were: Remove and flush the washer reservoir once every year or two. Perhaps add a drain hole to the bottom so that it doesn't involve removal.
There are also several commercial anti-freeze windshield washer solutions (including the Porsche flavor that you can buy at your dealer) that contain methanol/alcohol/who knows what. They sound nasty and will probably kill whatever is living in your tank while being reasonably safe for your car's finish.
Another list member suggests that isopropanol and water would be the best/cleanest windshield cleaner. Isopropanol is significantly more expensive than methanol which is probably why it's not used in the commercial anti-freeze/deicers.
Other possibilities include a vinegar/water solution, or some of the chemical products used for killing algae and bacteria in drinking water (RV and boat water tanks).
Things you probably don't want to run through your pump and washer system:
On 944's, the power steering pump belt and the polyrib alternator belt are both tensioned by turnbuckles having eyebolts at each end. When you tighten or loosen these turnbuckles, it is absolutely mandatory that you first loosen the through-bolts through their eyebolts.
Think about what goes on here: as the turnbuckle grows shorter or longer, its ends pivot around their throughbolts. If you don't loosen the latter, two things happen. First, you will bend, stress, and eventually break the eyebolts. Second, you will have to force the eyebolt threads inside the turnbuckle body.
You may notice on your car that one or more of the eyebolts isn't true, or doesn't thread easily in and out of the turnbuckle body. This is the product of someone not following the above advice in the past. Replace the part before it leaves you stranded.
By the by, the alternator belt turnbuckle originally had M8 hardware, upgraded by Porsche to M10 at some point. If you find you have the old style turnbuckle, you should give some thought to an upgrade.