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<blockquote data-quote="cj428mach" data-source="post: 12895706" data-attributes="member: 142081"><p>My EEC in my street rod has 30pts (basically graph points) of air flow to cover the 0-5 volts the MAF sensor sends out. For each point on the graph you have a known voltage and airflow that happens at that point. So when the computer sees that voltage it says hey I'm flowing this much air, now I need to add this much fuel. So rarely when you're hitting the throttle does it land on exactly one of those 30 voltages. So most of the time the computer has to calculate what the airflow is between any two voltages (points on the graph) to be able to put in the fuel and this number may not be 100% correct. </p><p> </p><p>Now its easy to see that if you had a MAF that flowed 30 kg/hr of air that you have 30 pts to cover (plot you air flow) so each point on the graph would cover 1 kg/hr. </p><p> </p><p>If you had a MAF that flowed 3000 kg/hr of air that you would have 30 pts to cover your air flow so each point on the graph would have to cover 100 kg/hr. So when the eec gets its voltage from the MAF and it falls between two points on the graph its calculation isn't as good.</p><p> </p><p>Ideally you want your MAF to cover the airflow of the engine with just a little safety factor in. For another example, if your engine flows 800 kg/hr and you have a big maf that flows 1600kg/hr then you're wasting approx. half your data points for the EEC to use to calculate airflow that could be used in lower voltages (aka daily driving). If you have a MAF that flows 1000kg/hr on your 800 kg/hr motor then you shifted more of those datapoints down into lower voltages.</p><p>here is a maf curve if that helps explain how it all works. </p><p></p><p>voltage / airflow in kg/hr</p><p></p><p>maxv 1686.489</p><p>4.840 1485.619</p><p>4.679 1342.411</p><p>4.519 1220.115</p><p>4.359 1104.788</p><p>4.198 993.581</p><p>4.038 887.442</p><p>3.877 789.225</p><p>3.717 700.196</p><p>3.557 619.721</p><p>3.397 547.483</p><p>3.236 481.899</p><p>3.076 421.385</p><p>2.916 364.989</p><p>2.755 313.029</p><p>2.595 264.870</p><p>2.434 222.098</p><p>2.274 184.712</p><p>2.114 153.346</p><p>1.953 127.366</p><p>1.793 106.138</p><p>1.633 87.762</p><p>1.472 71.287</p><p>1.312 55.762</p><p>1.152 41.822</p><p>.991 30.099</p><p>.831 22.178</p><p>.671 16.475</p><p>.644 13.941</p><p>0 0 </p><p></p><p>Not a perfect answer but it gets it close I think.</p></blockquote><p></p>
[QUOTE="cj428mach, post: 12895706, member: 142081"] My EEC in my street rod has 30pts (basically graph points) of air flow to cover the 0-5 volts the MAF sensor sends out. For each point on the graph you have a known voltage and airflow that happens at that point. So when the computer sees that voltage it says hey I'm flowing this much air, now I need to add this much fuel. So rarely when you're hitting the throttle does it land on exactly one of those 30 voltages. So most of the time the computer has to calculate what the airflow is between any two voltages (points on the graph) to be able to put in the fuel and this number may not be 100% correct. Now its easy to see that if you had a MAF that flowed 30 kg/hr of air that you have 30 pts to cover (plot you air flow) so each point on the graph would cover 1 kg/hr. If you had a MAF that flowed 3000 kg/hr of air that you would have 30 pts to cover your air flow so each point on the graph would have to cover 100 kg/hr. So when the eec gets its voltage from the MAF and it falls between two points on the graph its calculation isn't as good. Ideally you want your MAF to cover the airflow of the engine with just a little safety factor in. For another example, if your engine flows 800 kg/hr and you have a big maf that flows 1600kg/hr then you're wasting approx. half your data points for the EEC to use to calculate airflow that could be used in lower voltages (aka daily driving). If you have a MAF that flows 1000kg/hr on your 800 kg/hr motor then you shifted more of those datapoints down into lower voltages. here is a maf curve if that helps explain how it all works. voltage / airflow in kg/hr maxv 1686.489 4.840 1485.619 4.679 1342.411 4.519 1220.115 4.359 1104.788 4.198 993.581 4.038 887.442 3.877 789.225 3.717 700.196 3.557 619.721 3.397 547.483 3.236 481.899 3.076 421.385 2.916 364.989 2.755 313.029 2.595 264.870 2.434 222.098 2.274 184.712 2.114 153.346 1.953 127.366 1.793 106.138 1.633 87.762 1.472 71.287 1.312 55.762 1.152 41.822 .991 30.099 .831 22.178 .671 16.475 .644 13.941 0 0 Not a perfect answer but it gets it close I think. [/QUOTE]
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