Water Methanol Injection System

The SpeedTune Water-Methanol Injection System (part ST-WM-LCD-01) sprays a fine mist of water and methanol into the intake air of a turbocharged engine, either just ahead of the throttle body or in the charge pipe. An LCD touch-screen controller watches boost and switches the injection on once the boost you set is reached, so it only works when the engine is under load.

How it helps: as the mist evaporates it pulls heat out of the charge air, so the engine breathes cooler, denser air. SpeedTune quotes an intake-air temperature drop of around 20 degrees. Methanol is also a fuel with very high knock resistance, and the water slows the burn, so the engine gets more margin against knock. That matters most when a turbo car is driven hard and heat soak would otherwise pull timing and power, and it gives a tuner room to run more timing or boost safely.

The controller: the screen shows live boost in bar and the pump status, and the system is switched on and off from the screen. Three values are set on it, as labelled on the display: Start (the boost at which injection begins), Full (the boost at which it reaches full flow) and Power (the pump output).

Includes:

• Reservoir tank with filler cap
• Injection pump with mounting brackets
• LCD touch-screen controller with control module and wiring harness
• Solenoid valve
• Injection nozzles and fittings
• Feed line
• Power and signal wiring with an inline fuse holder

Fluid: the system runs methanol, ethanol, or either one mixed with water. Most street setups use roughly half water and half methanol. Use distilled water and pure methanol rather than windscreen washer fluid, whose additives can clog the nozzles.

Tuning: injection on its own cools the charge. To turn the extra knock margin into power, the ECU calibration has to be set up for it. If the calibration adds timing or boost because of the injection, the engine must stay safe when the tank runs empty, so keep it filled and talk to us about the setup.

Installation: professional fitting is recommended. Nozzle position, nozzle size and the Start / Full settings are chosen for each engine; UNDER10 can fit and set it up at our shop in Johor Bahru.

Safety: methanol is toxic and highly flammable. Fill and store it with care, keep it away from heat and sparks, and route the lines away from hot exhaust parts.