[Dave at Pelican Parts]

The main problem with superchargers in a 914 is packaging. If you go upright, you can use the fan belt to power a supercharger as well (or use the SC belt to run the fan) but there isn't any convenient place to run a good large belt on a 914 motor. At least, not one that lets you mount the charger without cutting holes in the firewall....

It can be done, but it's kinda non-trivial.

--DD