I was using the snow performance kit which calls for a 50/50 mix of methanol and water when I was running 10 lbs of boost on the Eaton M90 and it was definetely necessary to control detonation on CA 91 octane fuel. Now on the M112 since it is only making 5lbs of boost I temporarily disconnected it. When I make more boost from the M112 I will reconnect it. Let me get this strait you are saying I can make more power by just using water instead of the 50/50 mix of water methanol? If the pump is compatible with just water?
Water only made more power on our blown Mustangs. I am not an experienced engine designer or chemist but there can only be so many reasons for the power increase on the cars. One is water will absorb a lot more heat vaporizing than alcohol so it might make for a cooler charge and take up less space in the combustion chamber than a water/alcohol mix. Since the blower is shoving the same amount of air, or maybe slightly more, into the cylinders the extra fuel needed to keep the A/F right will make more power than alcohol due to its higher specific energy. Using water may have made the tune more consistent by keeping the control of metering the fuel in the hands of the tuner. When spraying alcohol that isn't factored into the computer's engine adjustments, based on sensor inputs, it may make the tune more hit and miss function. Or it could be a combination of all these factors. The fact water made more power on four different blown cars was too much to be coincidence. The power difference was around 5-6%.
The key is to make sure the pump is water compatible. We all had to swap out our pumps in a few months because they were rusting pretty bad.
Also, it was critical for us to use a smaller nozzle. The one we used for water/alcohol or straight alcohol was too large and would bog the engine. I am not familiar with the Snow kits. They weren't available at the time. We used an SMC kit that the turbo Buick guys used and modified it for our cars. SMC eventually sold a kit that was capable os increasing the spray pressure as boost pressure and/or RPMs increased. The volume of air flow determines the amount of liquid needed to cool the air and air flow volume changes greatly with RPM. Without this adjustment ability you need to pick what RPM range you sprayed for and it could cause the engine to bog off the line because too much water and/or alcohol was sprayed at lower RPMs.
IMO, I think the power increase came from the higher specific energy of gasoline compared to alcohol and the tuning was more precise since only finely metered fuel was used and the computer knew exactly how much fuel entered the combustion chamber.
