It will certainly help if done correctly. I have seen some MEAN setups. The example I like to use is one about a guy on the DSMlink forums. He posted a log indentical to the one I got from my 11.3 at 126 run. The difference was I was on 10 dollar per gallon race fuel, and he was on pump with water/meth injection.
And in fact, he went out and trapped 126 mph with it as well, and then even better eventually. He had quite the setup though. I recomend lots of research. I could sum up what I Think works based on other's results, but I have never tried it, so you would be better off to look into it on your own. See if you can find this guy on the national forums, I believe his name was Ron Francis, Lokmeup as a screen name. I think he even had a web page made with details of his setup.
FWIW, I'm thinking of trying something like this. Water/alky/meth injection is immensely popular with EVOs (most poeple use a prebuilt kit available from the EVO vendors, like the Snow kit, look into that one, even summit carries it IIRC). I'd like to try something a little different though, like what Ron did.