Dialing-In LTFT's

[07SD]

Below are part of the summary report from my recent logs. I adjusted up by 1% after the first then drove about 100 miles and ran the 2nd log.

DSLogRedux (great tool BTW!) is telling me to make another LTFT adjustment, but when I look at the data I tend to think that no more adjustment is needed. The logs were at about 75 MPH, just under 1900 RPM, in 6 gear, on the same section of flat road in the same direction.


DSLOGREDUX PREDATOR DATA SUMMARY REPORT
________________
Date of Log 02 11 09
CRUISE DATA REDUCTION RESULTS:
Average LTFT, Bank 1= -1.05742 %
Minimum LTFT, Bank 1= -2.34000 %
Maximum LTFT, Bank 1= 0.00000 %
Average LTFT, Bank 2= -2.99979 %
Minimum LTFT, Bank 2= 0.00000 %
Minimum LTFT, Bank 2= -3.13000 %

RECOMMENDATION: Adjust Inj Slope UP by 1%, Set the following adjustment on the Predator Tool: +1%

Average Throttle Position during Cruise Measurement= 37.44895 %
Standard Deviation of Throttle Position During Cruise Measurement= 0.00346 %
Number of Data Points contributing to Cruise Calculations= 10836
_____________
Date of Log 02 15 09

CRUISE DATA REDUCTION RESULTS:
Average LTFT, Bank 1= 0.78000 %
Minimum LTFT, Bank 1= 0.78000 %
Maximum LTFT, Bank 1= 0.78000 %
Average LTFT, Bank 2= -1.46707 %
Minimum LTFT, Bank 2= 0.00000 %
Minimum LTFT, Bank 2= -1.56000 %

RECOMMENDATION: Adjust Inj Slope UP by 1%, Set the following adjustment on the Predator Tool: +1%

Average Throttle Position during Cruise Measurement= 38.69858 %
Standard Deviation of Throttle Position During Cruise Measurement= 0.00362 %
Number of Data Points contributing to Cruise Calculations= 10693

[Grumpy_Aero_Guy]

My response would be that you are adjusted fine. The LTFT thing is a moving target and a function of many variables.

If you are dialed in such that you get a small adjustment recommended, as you describe above, I would throw up the touchdown sign, and monitor again when the outside temps start creeping up as we get into the summer months --- assuming you live in a climate where there is a real winter, rather than FL or AZ, or somewhere like that.

That's kind of the way I approach it with my truck. You'll never get adjusted perfectly and have it stay there all the time. Too many variables.

Just my $0.02

Looks like you're good.

Now, given THAT, did you do a couple of WOT bursts to see where your PE AFRs are?

[07SD]

Thanks for the info. I think I'll leave the LTFT's alone for now. I have now done any WOT stuff yet; next time I get out to I-95, I'll make a WOT log and see how it looks.

Many thanks to you and Lew! The DSLodRedux tool is fantastic!! It helps give confidence in making adjustments.

[06MonteSS]

yeah, your numbers look good man...


and thx for the good words - glad you like it and find it useful!!