AF ratio, can someone explain
10-24-2002, 12:14 AM
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AF ratio, can someone explain I dont know a lick about AF ratios. Whats good, whats bad. Is there a cirtain ratio that I want my car to be at the whole time or what. Tell me everything I need to know. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
10-24-2002, 10:26 AM
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Re: AF ratio, can someone explain Right, 14.7:1 (14.7 being the air and 1 being the fuel) is called stoichiometric (for the type of fuel we run) and is what our fuel systems try to maintain during closed loop operation (this is for best fuel economy and lowest emissions. At WOT, however, we need a richer mixture for better power and better detonation/pre-ignition fighting. Best WOT mixture is usually between 12.5-13:1.
10-24-2002, 11:24 PM
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Re: AF ratio, can someone explain </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> .95is fairly rich but it depends on your exhaust gas temperature. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">exhaust gas temp... oh no more variables witch one is more acurate and easier to work with. Im looking to buy a scaner tool to hook up to a PDA, and all the other lil stuff so I can see my AF ratio relative to my RPM's and do some tuning myself. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />
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10-26-2002, 12:21 AM
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Re: AF ratio, can someone explain EGT would be more accurate if you know how to interpret the numbers.
Non-wideband O2 sensors (what our cars have) are not designed to be accurate at anything other than stoich. They can be used for a good ballpark idea of how rich/lean you're running at WOT but that's about it. .930mv is generally just a little on the rich side. .830mv is generally just a little on the lean side. .870-.910 is [i]generally]/i] about where you want it. The thing to remember is that O2 sensors vary from car to car and what fuel/air mixture makes best power varies from setup to setup.
Non-wideband O2 sensors (what our cars have) are not designed to be accurate at anything other than stoich. They can be used for a good ballpark idea of how rich/lean you're running at WOT but that's about it. .930mv is generally just a little on the rich side. .830mv is generally just a little on the lean side. .870-.910 is [i]generally]/i] about where you want it. The thing to remember is that O2 sensors vary from car to car and what fuel/air mixture makes best power varies from setup to setup.