Ha it's interesting that you mention water methanol injection. Unfortunately I'm all too familiar with water meth. I was actually the head tech at Snow Performance for two years while I was living in Colorado. I know that good stuff that can come from water meth but I've seen the bad stuff as well.
Unfortunately there are a few fundamental problems with water meth injection. One, with the additional air charge cooling and effective octane increase I'll be able to run a more aggressive tune (more boost and more timing) while still using pump gas. One of the biggest problems with these systems is reliability. They all use the same crappy Shurflo pump which was never designed to be used with alcohol. The progressive electronics control leave a lot to be desired. Most have major hysteresis and are not accurate at all. If you do run an aggressive tune then you'll have to run some kind of fail safe which adds even more cost to the system. You're looking at over $1000 to run a full system with good electronics, a decent sized reservoir, and a fail safe.
I'd rather spend that $1000 towards an intercooler which won't ever fail and doesn't require a fail safe.
