I've run WI instead of i/c mate, but it was impossible to fit an intercooler.
You could run a boost-sensitive WI setup and have better results compared to any intercooler. But reliabilty would be lower (more things to go wrong and then bang) and you'd have to refill it quite often (it would have to come in relatively early, so water consumption would be high)
I was going to fit an evo8 fmic but read a bit on WI (a lot from aquamist who ARE tying to sell it )
and from what i have read it would be suited to my style of driving (mainly off boost with the occasional foot to the floor)
at least until I take the car off of the road this winter to fully rebuild it
exactly, they try to show that WI is more important than it really is.
If you follow their instructions, you'll bog down the engine, they recommend far too much water.
It doesn't work like that
If you run high boost pressures with crap intercooler, stock pistons and stock turbo, then WI can be very effective.
But if you have a good FMIC, big turbo and low comp pistons, then the case for WI is very weak - try my water injection calculator, you'll get a feeling.