how does water/meth injection work?

Jordo!

Cools the charge, increases effective octane, and reduces likelihood of detonation. It was developed for fighter planes in WWII.

However, displaces fuel (i.e., gasoline) and air, so takes some experimenting to find the mixture of fuel, water, air, and methanol that works best for your application.

I recommend a progressive controller that increases the volume sprayed as boost increases. Also desirable to have some sort of warning light in case of clogged lines or low reserve levels.

Port injection is probably best, ideally with an injector for each runner; next best would be plumbing each intake tube; worst is spraying directly into the turbine as it may strip off coatings on the blades or even cause pitting. This potential problem is somewhat mitigated by using a very fine spraying nozzle on the injectors, so that the mixture is well atomized.

Some folks are big fans of it, others see it as a band aid for failing to run the correct octane for your tune.

Other negatives include the fact that methanol is incredibly toxic, so unless you buy premixed solution, you will be spashing that stuff around and mixing with distilled water yourself (only use distilled!) in the garage... also, methanol is pretty expensive, though still quite a bit cheaper than running race fuel.

I have a fair bit of experience with it -- and have mixed feelings about it in retrospect.

It can enable you to make greater power, but if it fails -- unless you have some sort of safeguard in place to pull timing or at least warn you so you can throttle off, whatever timing or boost you are running will probably be too high if the mixture runs out and that can lead to breaking a piston...

Google water injection -- tons of info out there...

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