What is a water methanol injection system?
A water-alcohol or water-methanol injection system is a system that sprays a fine mist of water and alcohol (typically methanol) into the intake of a combustion engine as an anti-detonant. As a result you can run more advanced timing and or increased boost on turbocharged automobiles. Additional benefits are a steam cleaning of the upper engine and cooling of the intake charge from the water changing phase when it hits the combustion chamber.
There are a number of water methanol injection systems available, they all work similarly and feature many, similar if not the same components. Some systems operate using pressure switches and have a pulsatile delivery which doesn’t deliver as constant of effects. Other systems offer proportional control but have limited programmability. I wanted to utilize the multi-core architecture of the parallax propeller to allow for proportional control that is completely customizable. Additionally, I wanted to offer an lcd screen to output the current engine load level as well as the load level of the pump motor or spray level. Another feature of this diy water methanol system is a float switch that prints “tank low, please refill” when the tank drops below a certain level
A few requirements exist for a tank, mostly it must hold liquid and must be compatible with a mixture of 50% water 50% methanol and its desirable to have a non-vented cap.
- Many people use window washer fluid tanks out of old cars, or even the car they are installing the system in. Winter windshield washer fluid has high levels of methanol so these tanks are compatible.
- I opted for a new tank from US Plastics , their multipurpose tanks specifically are made from HDPE which is compatible with water and methanol and look to be the exact same tanks offered in commercial water-methanol systems
- SHURflo 8009-541-236 $59.99 60psi 1Gpm great for smaller engines
- SHURflo 8009-543-236 $79.99 60psi 1.8gpm internal bypass
- Aquatech pumps, Many commercial systems have switched to higher PSI aquatec pumps from SHURflo models in order to deliver smaller droplet size, keep in mind these pumps may draw more electricity. Mainly this seems to be the 5800 series pumps, an important note you want to make sure you get the correct model pump head for the pressure/flow you are going for not all 5800 models are good for this application. Make sure its 12v and has the pump curve you desire.
- Cooling mist pump I’m pretty sure this is one fo the aquatec pumps but its a good option $139.95
- Mcmaster part 7876K68 $52.56
- Ehcotech B20V I picked mine up here for around $25.00 shipped
- Mcmaster has nylon tubing 9685T3, 9685T4 $.85/ft, $1.81/ft respectively
- Home depot sells polyethylene tubing in rolls for $3-5
- This is similar to the one i used $5.79
- Mcmaster nozzles part numbers 3178K75, 3178K76, 3178K77 depending on engine size. The folks over at turbo mirage (great site, I highly recommend visiting it) recommend the 3178k75 for smaller cars up to 250hp, the 3178K76 for 200-450hp and the 3178K77 for cars above 400hp. These nozzles work great and are around $8.00 each however they are only threaded on one side so they might be harder to install in some cars.
- Devils own nozzles $12.50-$20.00 each, threaded on both ends for easier installation
- Cooling mist nozzles $26.95 each feature 90 degree fittings built in, they also offer a kit for direct port which is more expensive
- AEM nozzle kit $63.85