Again from autospeed: Experimental test data show that water injection into an unheated manifold, when the engine speed is reasonably high, will not give water a sufficient time to vaporise during the compression stroke. Of course, in normal operation of a naturally aspirated engine the water does not vaporise until after combustion is well under way. This effect well explains why injection of water into very highly compressed or supercharged engines has been successful.
It is well evident that water injection slows the combustion process down in SI [spark ignition] engines. Thus to maintain standard MBT [mean best torque] spark setting the timing should be advanced... when using water injection gasoline combinations. The use of water injection in water/fuel ratios from 0-1.5:1 caused the research octane number (RON) to rise from 70 to 93 and the motor octane number (MON) to increase from 64 to 90. NOx emissions were substantially decreased, being reduced by more than 50 per cent when a water/fuel ratio of 1.5:1 was employed. Lanzafame suggests that the best results of water injection come with a water/fuel ratio of 1.25:1. With an intake air temp of 143 degrees C and a water/fuel ratio of 1:1, the paper shows that peak cylinder pressure occurred about 20 crankshaft degrees later and that the peak cylinder pressure was reduced from 56 Bar to 37 Bar. With water injection occurring, rapid fluctuations in peak pressure were also much reduced. Exhaust gas temperatures also dropped, falling from 705 degrees C with no water injection to 692 degrees C with a water/fuel ratio of 0.5:1, 675 degrees C with a water/fuel ratio of 1:1, and 665 degrees C with a water/fuel ratio of 1.5:1. Look at the increase in octane rating! And also the ratio of water/fuel, who needs gas? FWIW, since I've been running it on our Westfield, we will be offering the Snow Performance kits shortly. Nice stuff, simpler and cheaper than the hydramist and doesn't require a programmable ecu. Bill Cardell TurboDog's Dad www.flyinmiata.com 1-800-FLY-MX5S (sales) 970-464-5600 (tech) 2008 FM Open House: August 14-17
_______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
