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IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now. Visit Preferences to set your user name Summary of change: This image is needed for the injectoropening. http://www.vems.hu/files/Firmware/docs/EffectiveFlowrate.png Unfortunately it still does not show up in the manual. [http://megasquirtavr.sourceforge.net/manual/Detailed.Output.Fuel.html#Config [Manual: Detailed.Output.Fuel.Config]] '''Basic req_fuel calculation''' '''Assume''' * fuel density=0.755 g/cc * AFR=14.7 at stoich * intake air density = 0.0012 g/cc (at MAP=100 kPa, which might be a cheat from the real 101..104kPa ?) * (alternate+1)*divider = N (see N below) '''Input data''' * '''I''' injector flowrate (cc/min) * '''D''' engine displacement (cc) * '''N''' number of injectors (piece, eg. 4 for a 4 cyl port injection) req_fuel = D / N * 0.0012 / 14.7 / 0.755 / I * 60000 The constant 60000 is responsible for scaling output from min (coming from the injector cc/min) to msec unit we usually use for this. The other constants are self-explanatory. '''Simplified equation is: req_fuel = 6.49 * D / N / I''' '''Examples''' ||'''D''' || '''N''' || '''I''' || '''fuel pulsewidth (msec)''' || '''req_fuel=0x..''' || || 1600 || 4 || 220 || 11.8 || 76 || We usually use 50% of calculated req_fuel and scale up VE values (j[] table) to double values (max values around 200, not 100) for somewhat higher precision. Note: ''bin/req_fuel.pl'' in firmware has a bit more featureful calculator, and there are many on the web. ---- '''See also''' * PortInjected/FuelInjectors * GenBoard/VerThree/LowZInjectors * OnlineCourse/InjectorOpening (advanced info for developers) Optional: Add document to category: Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.