Dry Nitrous oxide kits is exactly the same as a wet system apart from the additional fuel needed by nitrous oxide is added from the cars stock injectors. So a fuel solenoid and a additional feed from the fuel line is not needed. Now this seems to be a easier setup to install and your right it is as for as the nitrous oxide system is concerned but you still need the extra fuel to accompany the nitrous oxide. Now a simple fitting guide cannot be supplied for dry nitrous oxide systems as getting additional fuel from the cars injectors can vary from car to car. To produce extra fuel from the injectors you need to either increase the output pressure for the injectors or control the time they are on for via the cars computer management system. Obviously when nitrous oxide kits become active they would have to inject for a longer amount of time.