Calc. PE AFR vs. wideband, anybody checked?
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Calc. PE AFR vs. wideband, anybody checked?
Hi guys, who has a wideband and can tell me, from their experience, how the "calculated AFR" displayed in 8192 baud datastreams for MAF compares to what the actual WB declared AFR is? I just started using spark and PE tables from an 89 5 spd 3.45 geared 305 car on my 5 spd 327, since I am using the 305 heads. I show calculated 10.8 AFR in my datalogs at WOT. I used all of the 89 305 PE data, including the temp PE table. This is a lot richer than most of the 350 bins. The car does run great set up this way though. Some day I will have a wideband, just not today!
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From: Corona
Car: 92 Form, 91 Z28, 89 GTA, 86 Z28
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Mine was fine with '89 AUJM $6E on a 350. Matched almost perfectly if I remember correctly.
I found a problem a while ago with the PE tables in one of the commonly found .ecu's, that would cause the displayed AF to not match the tables (temp combined with RPM), but the displayed values were still correct and matched the wideband.
The fixed PE table factors can be found in this one - on Moates.net:
6Ev011JLSv1-07 LD Val scalar.xdf - the MAF scalars and table multipliers may not match your bin with this one. You can copy the PE factors from this, and then it will allow you to calculate your commanded AF without having to run your engine. Just add the temp and RPM PE's together, and that's how much enrichment you get. Like 14.7/1.18=12.45 where the .18 = 18% total PE.
You can actually set up TPRT conversion to display the calculated AF in the tables =1470/((0.390625 * X + -50.000000)+100)
Just remember that this is only 1 of the tables used (RPM PE), and the other will add fuel based on temperature = 0.390625 * X
I just uploaded a GTA 6E 10-16-05.xdf that I think has some better automatic number filling - wait never mind - there's some error uploading the file (and I'm still in China, so it's probably caused by that).
The factory calibrations are usually at rich best torque or richer.
I found a problem a while ago with the PE tables in one of the commonly found .ecu's, that would cause the displayed AF to not match the tables (temp combined with RPM), but the displayed values were still correct and matched the wideband.
The fixed PE table factors can be found in this one - on Moates.net:
6Ev011JLSv1-07 LD Val scalar.xdf - the MAF scalars and table multipliers may not match your bin with this one. You can copy the PE factors from this, and then it will allow you to calculate your commanded AF without having to run your engine. Just add the temp and RPM PE's together, and that's how much enrichment you get. Like 14.7/1.18=12.45 where the .18 = 18% total PE.
You can actually set up TPRT conversion to display the calculated AF in the tables =1470/((0.390625 * X + -50.000000)+100)
Just remember that this is only 1 of the tables used (RPM PE), and the other will add fuel based on temperature = 0.390625 * X
I just uploaded a GTA 6E 10-16-05.xdf that I think has some better automatic number filling - wait never mind - there's some error uploading the file (and I'm still in China, so it's probably caused by that).
The factory calibrations are usually at rich best torque or richer.
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Re: Calc. PE AFR vs. wideband, anybody checked?
Originally posted by 327_TPI_77_Maro
Hi guys, who has a wideband and can tell me, from their experience, how the "calculated AFR" displayed in 8192 baud datastreams for MAF compares to what the actual WB declared AFR is? I just started using spark and PE tables from an 89 5 spd 3.45 geared 305 car on my 5 spd 327, since I am using the 305 heads. I show calculated 10.8 AFR in my datalogs at WOT. I used all of the 89 305 PE data, including the temp PE table. This is a lot richer than most of the 350 bins. The car does run great set up this way though. Some day I will have a wideband, just not today!
Hi guys, who has a wideband and can tell me, from their experience, how the "calculated AFR" displayed in 8192 baud datastreams for MAF compares to what the actual WB declared AFR is? I just started using spark and PE tables from an 89 5 spd 3.45 geared 305 car on my 5 spd 327, since I am using the 305 heads. I show calculated 10.8 AFR in my datalogs at WOT. I used all of the 89 305 PE data, including the temp PE table. This is a lot richer than most of the 350 bins. The car does run great set up this way though. Some day I will have a wideband, just not today!
If you miss the tune, or the various corrections are wrong, then all bets are off about if the commanded, and actual AFRs, are going to match.
And once you go static, the commanded AFRs are meaingless. You can have commanded AFRs down to like 9:1.
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