{"id":13189,"date":"2012-06-18T06:24:39","date_gmt":"2012-06-18T11:24:39","guid":{"rendered":"http:\/\/caddyinfo.com\/wordpress\/?p=13189"},"modified":"2012-06-18T18:41:58","modified_gmt":"2012-06-18T23:41:58","slug":"water-injection-or-methanol-injection","status":"publish","type":"post","link":"http:\/\/www.caddyinfo.com\/wordpress\/water-injection-or-methanol-injection\/","title":{"rendered":"Water injection or methanol injection"},"content":{"rendered":"

Water injection or methanol injection is a system that injects water or a mix of water and methanol into the intake of the engine.\u00a0 The fluid spray vaporizes, absorbing heat.\u00a0 This removes heat from the cylinder, acting as a sort of chemical inter-cooling for supercharged or turbocharged engines.<\/p>\n

\"Water<\/a>

STS-V Intercooler removed from Supercharger<\/p><\/div>\n

 <\/p>\n

In the Cadillac STS-V, air flows through the rear-mounted throttle body, into the supercharger, up through the intercooler, and down into the manifold.\u00a0 The IAT2 intake air temperature sensor after the intercooler is in the base of the supercharger section shown in the photo above in the top left corner in the air flow to the manifold.<\/p>\n

Water injection or methanol injection development<\/h2>\n

Water injection was originally developed and tested by Sir Harry Ricardo (1885-1974).\u00a0 Among other projects, such as development of the octane rating, Sir Ricardo did testing and development of water injection.\u00a0 His work was the basis for the German fuel MW 50, a 50\/50 mix of methanol (an alcohol) and water used in the WWII German fighter\u00a0 Focke-Wulf FW 190, and other Fighter aircraft.\u00a0 The methanol injection enabled the FW 190 to go from 1600 hp to 2000 hp.\u00a0 The P-51 also later used methanol injection.<\/p>\n

Post-war methanol injection was sometimes installed as an automatic power reserve system (APR) for use in hot or high altitude takeoff.<\/p>\n

Water \/ methanol injection in automobiles<\/h2>\n

The 1962 Oldsmobile F85 and Corvair Spyder offered water injection, as did the Saab 99 Turbo S later, after 1978.\u00a0 In automobiles as in aircraft the purpose of water or a mix of water and metanol is to cut the temperature of the incoming air in supercharged or turbocharged engines.<\/p>\n

\u00a0The science behind water injection or methanol injection<\/h2>\n

The latent heat of gasoline is 140 btu\/lb.\u00a0 The latent heat for water is 700 btu\/lb.\u00a0 This means that water will remove five times more heat when vaporizing than gasoline does.\u00a0 When water injects into the air stream, the fine droplets of water allow the most water surface area for rapid vaporization.\u00a0 Expansion of the water into steam also assists with cylinder pressure.\u00a0 A side benefit of water injection is removal of deposits in the intake track.<\/p>\n

Some will argue that lowering the air temperature or cylinder temperature in and of itself will not add power.\u00a0 Although lower temperature, denser air is available, without tuning to allow increased timing to take advantage of the lower temperature air there will be little gain.\u00a0 This argument overlooks the effective self-tuning of modern engines by removal of high incoming air temperature retard adders.\u00a0 More to the point however, tuning for a water injection or methanol injection at the time of installation is best.<\/p>\n

Water or water and methanol mix or 100% methanol?<\/h2>\n

Water injection alone provides air temperature and cylinder temperature reduction.\u00a0 Injecting a mix of water and methanol provides a mix of cooling and additional high octane fuel.\u00a0 Use of 100% methanol increases the fueling at the expense of some loss of cooling.<\/p>\n

100% water is not combustible.\u00a0 Up to a mix near 50\/50, a water and methanol mix has limited combustibility.\u00a0 100% methanol is highly combustible.\u00a0\u00a0 For refilling, water is most available, and a mix of water and methanol is commonly available in the form of low temperature windshield wiper fluid.\u00a0 Pure methanol is a speed shop or specially sourced item.<\/p>\n

A mix of water and methanol provides a good compromise between cooling, fueling, and safety.<\/p>\n

Components of a water injection or methanol injection system<\/h2>\n

A water injection or methanol injection system is relatively simple.\u00a0 A reservoir or tank holds the fluid, which is pumped at a high pressure to a nozzle.\u00a0 The nozzle atomizes the fluid, spraying a measured amount into the intake.\u00a0 The amount of spray depends on the type of nozzle and system pressure.\u00a0 The system may use boost pressure or other engine indicators to trigger spray.<\/p>\n

Methanol injection installed — Steve posted this report on his 2012 Cadillac CTS-V to youtube:<\/p>\n