02NBMFormula

iTrader: (6)

so i go driving to log ltft and have about 30 minutes when im stoped at a red light and i open the laptop to see the progress but pull the cable out of the HPTuners moduale, the one that goes from the USB port to the HPTuners box. so i pull into a parking lot and save that log and start loging for the way back home and get about 12 minutes of driving time.
so i get back and look over the two sets of data and the first log seems alright but the 2nd shorter one is 2-4 numbers higher. so which data should i tune from???

jimmyblue

iTrader: (11)

There will be a lot of "driving history effect" on the
lower-airflow cells, with headers; the O2s are going
to nod off given any opportunity, etc. About the best
you can do is "no positive trims", and tolerate the
wandering-about.

silverTA2002

iTrader: (1)

I'd average both sets of data.

Then make changes, drive 50 miles, then log again.......

Then repeat.

Get things as close as you can.

FWIW, the longer you drive, the more "accurate" the LTFT seem to be. At least I notice they seem to fluctuate less the longer I drive.

txhorns281

iTrader: (12)

If you are using you narrowbands to tune trims, when you reflash, let your trims learn a bit before trying to log any data. A good indicator of how well the trims have learned out is to watch your STFT histogram, when these values better center around 0 (+- 3) that means the associated LTFT has gotten to its general value. You don't have to "cruise" for 30 min, just drive around with the STFT histo up and sample areas of the chart that need more "learning." This will all depend on how well you can control your vehicle to sample the areas you need to. You can get your complete VE learned in 10-15 minutes if you control/manipulate the learning process. Once everything is well learned, start a new log to record your new data.

02NBMFormula

iTrader: (6)

this was all after driving for about a hour the day before to get the changes learned