What am I doing wrong STFT
Nov 8, 2017 | 02:00 PM
#22
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From: Somewhere north of 285, south of 985.
Yes.
However, if you still have LTFTs turned on and they are more than +-5, this gets factored into your commanded PE and skews it.
Most of us disable LTFTs altogether. There is no harm in doing it.
Ideally, what you command in the PE table should match what is on the AFR gauge pretty close.
As FFDP suggested, lean it out some. This is known as rich knock.
However, if you still have LTFTs turned on and they are more than +-5, this gets factored into your commanded PE and skews it.
Most of us disable LTFTs altogether. There is no harm in doing it.
Ideally, what you command in the PE table should match what is on the AFR gauge pretty close.
As FFDP suggested, lean it out some. This is known as rich knock.
Nov 8, 2017 | 02:05 PM
#23
Correct, the power enrichment EQ ratio is what is used during WOT for a commanded AFR.
Staying around a 12.0 commanded is still safe if you don't have a wideband hooked up into your log files. For future reference PE EQ ratio is a set it and forget it table. Once you pick and AFR/Lambda to run you tune it to achieve the number. Like if you request 12.0 but the wideband showed 12.3, it would be slightly lean of commanded. You would add in fuel via the MAF/VVE to bring it down to meet the commanded number. Same thing but the opposite if it was 11.7 with a requested number of 12.0, removing fuel would be wanted.
Using a little less fuel could help with the knock here, it's a simple test to see how it responds. If knock is still present, lower the commanded timing at WOT. If 25-26 commanded timing is too high and showing knock, lower it to 22ish or where ever the vehicle see's fit.
Staying around a 12.0 commanded is still safe if you don't have a wideband hooked up into your log files. For future reference PE EQ ratio is a set it and forget it table. Once you pick and AFR/Lambda to run you tune it to achieve the number. Like if you request 12.0 but the wideband showed 12.3, it would be slightly lean of commanded. You would add in fuel via the MAF/VVE to bring it down to meet the commanded number. Same thing but the opposite if it was 11.7 with a requested number of 12.0, removing fuel would be wanted.
Using a little less fuel could help with the knock here, it's a simple test to see how it responds. If knock is still present, lower the commanded timing at WOT. If 25-26 commanded timing is too high and showing knock, lower it to 22ish or where ever the vehicle see's fit.
Nov 9, 2017 | 10:49 AM
#25
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From: NC
Well I got commanded AFR to 12.23 and only had 1 degree of KR under WOT. So that's better.
But if you look at the 8 min mark of the log I still get a random 4 degrees of KR. I also get random 1 degrees of KR at random times.
But if you look at the 8 min mark of the log I still get a random 4 degrees of KR. I also get random 1 degrees of KR at random times.
Nov 9, 2017 | 12:31 PM
#27
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From: NC
Burst knock table didn't really help. One pull would be no knock then the next pull would be about 3 KR. Then I still get the random 3 degree out of no where or just a random 1 KR.
I'll post the last log when I get home. The truck feels better though.
I'll post the last log when I get home. The truck feels better though.
