[teknow]

If you are referring to the air duct that runs to the back of the alternator then I recently read this was not introduced on the 924 for cooling, but to blow road salt clear of the alternator on European roads as the alternator is so low down.

That was written in a few road tests of the era, all remarkably similar and I reckon Porsche provided the data to all the journalists who copied it and added their opinions around it!