As far as i know (correct me if i am wrong) Wet is safer than dry. Dry you have to spray before the maf sensor and it compensates with extra fuel (or atleast you hope). Wet sprays fuel and nitrous into your engine after the maf sensor. Wet you don't have to worry about fuel. Dry you have to wonder if your maf will keep up with the nitrous you are putting in. Safer bet would be to go with wet. But there are no FOR SURE's with nitrous. I personally would not put nitrous on a tr. I have enough problems getting my boost to work right much less, boost and nitrous. But i am pretty sure wet is the lesser of the 2 nitrous evils.