It is very common if you are dealing with a newbie or some wannabe cock smoker who is just reciting part information from the things I was speaking about 10+ years ago that you will get an inferior result.
Water Injection needs correct calibration, and proper system set up for supporting engine ancillaries, without the "whole package" of both parts and knowledge you will never get the full benefit of it and in many cases you will make you car package worse by applying it where it is not even needed in the first place
