METH/WATER INJECTION - How it works

[JP@edgeautosport.com]

Alan over here at EdgeAutosport wrote a great, quick write-up on methanol/water injection for the Subaru guys so I thought I'd copy and paste here. Read...

Here is a little info on water/meth injection that may help explain what is going on in the motor when you inject the mixture.

Injecting water can provide a number of benefits. Most people know that it helps when you are limited to running lower octane fuels, but I want to talk about why it helps. During combustion, the water is converted to steam. This conversion pulls heat out of the combustion process and slows down the rate that pressure in the cylinder rises. The steam particles that are created get in the between the fuel and oxygen molecules which also helps slow down the combustion and pressure rise rate. Meanwhile the piston is moving towards TDC (top dead center), squeezing the gases together. But, since there is less heat in the chamber and slower pressure rise, detonation is far less likely to occur. As the piston starts its descent a controlled burn continues, but the combustion flame now has to dodge around steam molecules plus an increasing number of exhaust molecules to get to fuel and oxygen molecules.

Now lets take a look at what meth brings to the table (besides making a lot of money but causing a ton of problems for certain high school chemistry teachers that is) /breaking bad reference

Methanol has a very high latent heat of vaporization compared to gasoline, but much lower compared to water. Because it vaporizes at a much lower temperature than water, the meth will pull heat from the intake tract, the piston crown, and the intake and exhaust valves where the temperatures are much cooler than that of the combustion event (where the water comes into play). Because internally, the engine is cooler, less heat will be put into the combustion charge resulting in higher mixture density in the cylinder. Furthermore, less heat means slower burn.

So with a cooler combustion chamber and steam molecules resulting in a slower burn, spark advance and boost pressure can be increased resulting in more horsepower and improved throttle response.

[JDW1]

Now you can recommend a good kit for me with a fail safe.

[JacksonMS30]

Originally Posted by JDW1 Now you can recommend a good kit for me with a fail safe.

AEM makes an awesome Failsafe that will work with pretty much any kit.

Water/Methanol FAILSAFE Device - 1/4" SAE

[EdgeAutosport.com]

Check out this one They dont have a solenoid with the kit but as long as you mount the tank below the pump you will be fine. We can get you a solenoid for 52.50 also

Performance Stage 2 Boost Cooler Methanol/Water Injection System

[EdgeAutosport.com]

Bump! This is a good resource! Educate yourself and your experience with your car will be better!

[LumberJack]

Nice write up, great info! Will be going with a Meth kit on my BT build!

[SC08Speed3]

Great info! Im trying to decide exactly which set-up I wont to go with when i go BT..

[The Panda]

Most kits are going to be good such as Devils own and aem and snow.... what is important is how it is setup such as running of maf voltage.

[pwdunmore]

I was about to order the Snow Performance silicone adapter for the Stage 2 MAF kit I ordered already(through a GB)... was just wondering if I should be buying anything else. I was planning on mounting the kit somewhere it's easy to fill.

Is there a shopping list of crap I am going to need to do the install?

[EdgeAutosport.com]

Originally Posted by pwdunmore I was about to order the Snow Performance silicone adapter for the Stage 2 MAF kit I ordered already(through a GB)... was just wondering if I should be buying anything else. I was planning on mounting the kit somewhere it's easy to fill. Is there a shopping list of crap I am going to need to do the install?

There isn't too much outside of the kit that you will need to buy. In order to mount the tank, you may need something to make a bracket out of and the hardware to mount it, but thats about it. Same for the pump too. Just something to make a bracket with.

-Alan