Benefits of Methanol/Water Injection in Automotive Applications
What is Meth Injection?
Methanol and water injection systems (also known as meth injection) add a mixture of alcohol and water into an engine's combustion chamber. This process cools the combustion chamber and thereby reduces pre-detonation and engine knock. Through this means meth injection can allow engines to safely make more power. This bump in power comes from the ability to advance ignition timing and/or increase boost without damaging engine internals through pre-detonation. A simple way of thinking about the benefits of methanol/water injection is to consider it as a method of increasing the octane rating of your fuel.
Power Benefits & Cost
Water/methanol injection systems can be used on both naturally aspirated and boosted vehicles with only a small hit on your wallet. Meth injection systems, such as those from Snow Performance, can be had for only a couple hundred dollars. This puts their price on par with many aftermarket cold air intakes, but the performance advantages of meth injection are much greater. Refilling your tank with methanol is also not a large expense. Typically you can just use the winter mix of windshield washer fluid (-20 degree F rating). Meth injection systems allow many otherwise stock cars to produce more power by preventing the car's knock sensor and ECU from retarding ignition timing. With meth injection you can also safely increase boost levels on your turbocharged vehicle and see power gains of up to 20% with an aggressive tune. Even bone-stock low compression (less than 10:1) naturally aspirated engines can see ten to fifteen horsepower on a warm day. Engines using nitrous oxide systems can also see very large power gains because ignition timing does not need to be retarded nearly as much. In some cases, the addition of meth injection will allow you to run nitrous without retarding ignition at all. All of these gains come from lower air intake temperatures, increased charge air density, and advanced ignition timing.
Aside from boosting power, meth injection can simply make engines more efficient. This means improved fuel economy as well. With a proper tune, an engine with methanol/water injection can run lean air fuel ratios without pre-detonating. This means that the engine will safely be using less fuel for the same amount of power. In addition, the process of injection water and alcohol cleans the combustion chamber of carbon deposits. This promotes engine health and reduces future losses in power, saving you money.