Snow Performance has combined performance, quality, and easy installation in this new water-methanol injection system engineered specifically for your 2005+ Subaru WRX STI equipped with the 2.5L engine. Increase your pump gas octane by 25 points and make more power efficiently with a cooler running motor! Complete with custom water-methanol injection throttle body spacer plate, braided stainless line, and 4AN fittings offering un surpassed reliability and ease of install. The Stage 2 uses a progressive VC-50 controller (ISO 9001 Manufactured) that proportionally injects more or less according to boost pressure. Start and full points are adjustable for engagement and delivery curve to match what the engine requires. Proportionally injecting according to boost pressure gives an accurate delivery of water-methanol and allows cooling and performance improvements over a wide range for improved drivability. The VC-50 controller (52mm gauge) offers the functionality of a boost gauge and water-methanol controller all in one! Highlighting a 7 color (Blue, White, Red, Yellow, Orange, Purple, Green) OLED screen displaying boost, percentage of injection, low level, secondary nozzle activation, prime button, and 2 fault codes directly on the screen you can tailor the controller to match your OEM gauges or mix and match up to two colors. Fits all 2005-2014 Subaru WRX STI 2.5L engines.