heres something i found on wet and dry kits
Here are a couple FAQs
Q.what is the difference between a wet and a dry kit ?
A. A dry kit injects nitrous oxide , where as a wet kit injects petrol and nitrous oxide.
a dry kit is used mainly for diesel engines , using on a petrol engine will result in very poor gains , if you were to use a dry kit to go for large gains then your engine would end up running lean and get severely damaged, the wet kit ensures the correct fuel and air mixtures are injected into the engine to stop this from happening .
Q.will nitrous oxide damage my engine?
A.No, providing you do not add more than 50 percent extra power to your vehicle these kits will not cause any engine damage , so for example if your car is 100hp it is SAFE to add an additional 50 hp using a nitrous system