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sjf911 sjf911 is offline
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Join Date: Dec 2006
Location: Idaho
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Water has a substantially higher latent heat of vaporization than methanol so the cooling effect is greater but displaces fuel/air. Methanol adds "octane" and fuel so a mix makes sense, especially given the fire hazard of pure methanol. From what I have read, the recommended injection rate is about 10-25% of your fuel flow by weight. I run a 60:40 (H2O:alcohol by volume) at about 9% of fuel with mine since I have a full bay intercooler and relatively low boost and intake temps. The highest performance water/meth injection systems I have seen use individual injectors per cylinder and avoid upstream injection, especially if there are significant bends in the intake plumbing to avoid centrifugal separation. My injector is upstream of the throttle body and around three 90 degree bends in the intake plumbing so it is not ideal from that standpoint. I do use a high pressure system and high efficiency injector nozzle to improve atomization. My system also has a flow meter and built-in safeguard capability for flow failure monitoring and feedback.
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1983 3.4L 911SC turbo. Sold
Old 09-13-2010, 06:19 AM
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