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stft ltft and maf scaling help needed.

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Old 10-21-2014, 07:46 AM
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stft ltft and maf scaling help needed.

Ok I have about 3 decent length datalogs. And on 2 of those at idle I'm at 7gs. And I know the recommended is 5.5 but on my last log. I'm right around 5.45-5.6 at 800-850 rpm. So shook I adjust my scaling or leave it be ?

Also on my stft and ltft I'm in the 22 and -22 range to me this doesn't sound right , isn't it supposed to be closer to 0 ? And my air/fuel is around 14.6. Which sounds ok
Old 10-21-2014, 08:35 AM
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Positive and Negative 22?

Is it hunting? Going from high negative to high positive? If so, you likely have a turbulent airflow in the MAF housing.
Old 10-21-2014, 09:14 AM
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rpm maf stft ltft load

832 5.49 22.656 -22.656 38
855 5.45 22.656 -22.65 37
889 5.63 25. -22.656

I know this isn't much but it was my quick log

It doesn't seem to be going from positive to negative it's pretty consistent. I have a aem with 2 screens inside

Last edited by nlsolja123; 10-21-2014 at 09:18 AM.
Old 10-21-2014, 05:05 PM
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LTFT are positive high, and STFT are negative high....so they are effectively canceling each other out.

Looks like you had an issue and have since resolved it. Do the 20 brake stomps and then see what happens.
Old 10-25-2014, 08:48 AM
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ok i did that, and retested over the course of 2 days worth of driving. my log from last night are pretty different. im getting -14 to -21 ltft at all times. my stft is -16 to +23. its looking like im about -20 at idle combining the trims. and around -10 under slight load

heres the zip with the log inside, its a tactrix log so im not sure if you can check it out or not
Attached Files
File Type: zip
log0019.zip (54.7 KB, 17 views)
Old 10-25-2014, 09:23 AM
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Based on your other thread it seems that you may have an O2 sensor problem (likely your stock O2 since I assume the AEM is new) so I would not continue tuning until you get that sorted since O2 readings you are using to tune are from the stock O2.
Old 10-28-2014, 07:51 AM
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Got a used sensor from a wrecked rx8 at the jy. It seems the aem wideband is junk. It's about .5 to 1.0 off. It only reads the same as my stocker at wot

I have rewatched some of the tuning videos again. Mainly video 3 I changed my injector scaling to 386.53 and my lt is 0 and my short term is around -/+ 5. Should I leave this be?
Old 10-28-2014, 09:10 AM
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TX

Originally Posted by nlsolja123
Got a used sensor from a wrecked rx8 at the jy. It seems the aem wideband is junk. It's about .5 to 1.0 off. It only reads the same as my stocker at wot

I have rewatched some of the tuning videos again. Mainly video 3 I changed my injector scaling to 386.53 and my lt is 0 and my short term is around -/+ 5. Should I leave this be?
Is there a calibration process for the AEM? and you want your stft to be +/- 0-3%.

I would still get a new O2.
Old 10-29-2014, 09:23 AM
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Just wondering. On the fuel trims I'm guessing I need to scale the injectors. What's the typical range stock injectors should be scaled to. I know everyone is different but I got mine at 387 and that gives me a Ltft of 0 and short term is kinda high . Does this seems to much ?

Last edited by nlsolja123; 10-29-2014 at 09:34 AM.
Old 10-29-2014, 09:44 AM
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Did you scale your MAF? Sounds like you are in over your head.
Old 10-29-2014, 07:13 PM
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I Did not. I am doing that at the moment and returned to a stock flash withonly omp adjustments.

Going by the tuning videos, i misunderstood and thought since my idle is at the correct 1.21volts at 5.4 g/s that i didnt need to do this. now i understand i need to go make some 2nd gear slow pulls, and look at my fuel trims and scale it from that % of deviation.

this is correct right?
Old 10-30-2014, 06:37 PM
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Yup
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