Actually, if you mist or fog the water effectively, it evaporates before you put it to real use. Evaporation causes cooling, and we already know cooler air is denser. Water injection has been proven on the track and dyno in cars. It'* first automotive use that we have historical reference for is at Daytona in 1911. Back when they still ran on the beach.
Water injection was also used on B17'* and B-24'* in WWII. These Supercharged, water injected engines were the reason our bombers had higher service ceilings than the opposing forces. Between the superchargers scavenging air at high altitudes, and the water injection cooling that air (and the mechanical gear-driven superchargers), we performed far better than without those features.
An article I'll never forget was written by a guy that track-races his Miata in the Phillipines. The heat and the humidity there are atrocious. I can tell you from experience. He was overheating, and his car was stumbling by his 5th or 6th lap around the course, as were his friend'* cars. He built a simple system by converting his washer bottle tank, and immediately began winning races. The water injection helped him overcome the humidity problem on a NA car. I can dig up some of the articles on this if anyone is interested. I've been staying on top of the WI theory for 2 years now.
If you go to INTENSE'* website (www.intense-racing.com
) Scott writes that he'* not a fan of Water Injection for the simple reason that intercooling is a much safer, effective alternative. He'* right. Water Injection CAN be dangerous, which is why I go through alot of design for the system to be safe and preven the chance of hydro-lock. The problem is that us Series1 L67 hosers don't have the advantage of an aftermarket Intercooler solution.
System can be very simple
Always improves power
System break-down usually immediately recognisable
No ongoing maintenance
Major underbonnet changes
Usually poses a flow restriction
Water Injection advantages
Very effective at preventing detonation
System components can be spread around car
Can be used to inject octane booster
Generally low cost
No intake flow restriction
Reduces emissions (and carbon buildup)
Water injection disadvantages
Requires regular filling of water tank
System breakdown can be difficult to recognise
Large filled water tank is heavy
Variable flow systems are complex
Effectiveness will vary depending on weather
Water injection is primarily used to mask or band-aid engine configuration problems. A properly configured engine would not appreciably benefit from water injection. Wrong. Water injection can provide an unparalleled combination of intercooling, volumetric efficiency and detonation suppression. Under single use, either/or applications (using either high efficiency intercooler or water injection), water injection has proven to be markedly more efficient in dropping intake air temperatures (see Technical Tributaries...in the weeds for further information) in addition to increasing volumetric efficiency and active detonation suppression.
Wrong. Water injection can increase engine reliability, particularly for highly stressed motors and/or extreme running conditions such as hard street performance and racing applications. Atomized water effectively dissipates heat and actively suppresses the onset of damaging detonation. In fact, water injection can be very effective in countering the deleterious effects of running lean air/fuel ratio conditions.
And it could go on forever. The article I'm looking for (read it 2 years ago) involved 12 supertuners (Lingenfelter, Saleen, etc) that were invited to a challenge by a performance magazine. No forced induction (Nitrous, SC, Turbo) was allowed, but they could use Water Injection if they chose to. 10 of the 12 competitors showed up with Water Injection.