one more thing to consider for B20vtec guys: make sure you have a pcv system that is working (b20b/z lack pcv black box on back of block). when running higher amounts of water injection your blow-by will contain water vapor (along with fuel vapor). without pcv to clear it out of the crankcase the inside of the block will corrode over time and you may find condensation under the valve cover after the engine has cooled down which may lead to rust on the cams and valvetrain.

also, carefull how close you mount the mister to the t-body if you aren't confident of good atomization with your setup. just like a wet single fogger N2O system, the #4 cyl will run lean (less water mist in this case) and be more prone to detonation than the other three. each droplet of water has inertia that will make it resist the sharp turn into the #4 intake runner right behind the t-body...the larger the droplets, the less H2O that cyl#4 sees. cyl#4 runs hottest of all so it's even more inclined to detonate anyway (hottest water exits the head at the #4 end of the head).

a friend of mine was running 26psi on a stock internal talon engine (upgraded turbo, etc) on 91oct with 100% methanol injection and zero knock count. i didn't believe in WI until i saw that. now i'm sold.