For reference I used my progressive set-up more for insurance against crap gasoline and better intake charge cooling.

I can't confirm how well it worked for the first part of that other than the bottom end of the engine had over 200,000+ miles on it and I ran it at 22#'s for SEVERAL years even at road course track day events and never had a problem. I think it finally popped the head gasket because I was beating on it pretty hard and it got a little hot (not pegged). I never heard detonation, but with my Shel-Game cal with the CEL knock detection it would light the CEL up almost as soon as it hit boost, regardless of whether the water/meth injection was on, or what I had it set at. We figured it was a defective knock sensor, but I never got around to replacing it.

Now, as for keeping the intake charge cool, this I can 100%, without a doubt, confirm! At track day events I ALWAYS ran the injection. As soon as the session was over, I'd get to the paddock and pop the hood and there was condensation on the intake manifold! Also, the engine NEVER got hot on track. I have my doubts as to whether the stock cooling system would have been able to keep up, even with the large oil cooler I run.

I will also say that when I had the car on the dyno I tried running it with and without the injection turned on. It made NO difference in power or torque. I attribute this to the fact that I wasn't taking full advantage of the system. Plus, IF the engine was knocking (inaudible), it would have been pulling timing regardless of whether the system was on or not. I never saw any "salt & pepper" on my plugs, but one of the pistons did show minor signs of detonation, but it wasn't pitted much, more like rough to the touch.

I always set my system to come on around 10-14#'s and fully on at 18-20#'s. Of course at WOT that delay was not very long at all, but I have a feeling that it did help under part throttle, high load, high(er) boost. That is where a lot of my concern was as that is a recipe for blown up engines! Right, Brent? (just messing with ya: nudge nudge)