The premise behind water injection is simple: Squirt a mixture of water and methanol–windshield washer fluid, basically–into the engine’s combustion chamber to cool the intake charge and prevent detonation.
A few factors decide a given fuel’s detonation point: intake air temperature, ignition timing and cylinder pressure combination. Cylinder pressure can be developed by compression ratio, supercharging or turbocharging. If you can reduce one of the three variables, then you can increase one or both of the other two.
The water/methanol mixture vaporizes and cools the intake charge significantly, allowing you to increase the timing and boost. In layman’s terms, water injection can produce the same effects as high-octane race fuel–but without the cost or complexity of finding it at the pump.
This technique has been around for decades, but it has only become a mainstream modification in the past few years. Credit more precise engine control systems with making water/methanol injection durable enough for everyday use. Additionally, companies like AEM now offer turnkey, all-inclusive kits for less than $500.
Okay, so water/methanol injection is relatively easy to add. But is it really necessary? Here’s a handy guide to making that decision.
Step 1: Does your engine have a high compression ratio? Or is it fed by a turbocharger or supercharger?
If your answer is “none of the above,” then water/methanol injection probably isn’t a wise investment. If you do have one or more of these things, move on to Step 2.
Step 2: Can you adjust your ignition timing and/or boost pressure?
Installing water/methanol injection without retuning your engine will usually cost horsepower, as the water replaces some of the combustable air inside the engine. If…
Click Here to Read the Full Original Article at Grassroots Motorsports Online Articles…