RomRaider

Thanks for the reply.

For some reason i'm unable to replicate that issue i had. So i'm not sure what happened there.

Does the compare work? like without having to paste in original figures vs new? Doesn't work for me anyway.

Keep up the good work

"For some reason i'm unable to replicate that issue i had. So i'm not sure what happened there. " - perhaps you selected a wrong column?

"Does the compare work? like without having to paste in original figures vs new? Doesn't work for me anyway." - i'm not sure if understand you. on the plot you can see the curves from the base scaling you pasted in the original table and the resulting curve. if you want to compare the actual scaling values you can click on compare button which brings up a compare screen with 2 tables. you paste scales you want to compare and get the diff values. That screen doesn't have the plot with curves though. It does however allow you to paste in any scales for comparison, eg if you did several scaling iteration and want to compare against stock scale rather than against new base scale which is already modified from stock.

So what EXACTLY doesn't work for you?

I just signed up to the forum to say thank you to VGI and everyone else involved in the creation of this app. I've been tuning cars for about 10 years and this just did what use to take me hours and dozens of data logs to accomplish in under an hour with 2 data logs, including the time it took to get the car out on the highway for the data logging. After one shot with this program I flashed the new tune and made about 6 WOT runs through 3rd and 4th and STFT and LTFT never corrected once and my AFR's are glued to my target. I truthfully thought something had to be wrong but every stream of data from my logs looks flawless and the car is running the best it ever has.

I am honestly stunned and can't thank you enough. I am sorry for anyone that is scaling their maf right now without this.

Thank you. I have listed the people credit also goes to on the Usage tab for each functional tab.

If you or anybody else is still using spreadsheets for tuning or wasting time on something and have an idea on automating it - send those my way and I'll add new tab(s).

Thanks for this - very nice work! Using it now to retune after upgrading my worn out fuel pump.

One thing that seems to be off though - the rescale feature. It likes to cluster all the extra new points together right after the "Max Unchanged" MAFv. I expected it to spread the remaining data points evenly between "Max Unchanged" and "New Max V" instead.

Is there a reason for the clustering behavior that I'm missing?

you can check the "usage" tab on the logic used to apply the automated changes.

the program attempts to keep the same spacing ratio as the original points have. so naturally it will look like the new points are 'clustered' right after the 'max unchanged' mafv (more points towards low mafv and less points towards maxv). however the spacing between all points (or rather most of them as this is automated and the points on the original curve aren't spaced evenly) should still be reduced. you can manually calculate the diff between points spacing to confirm that.

if you don't like how the spacing is assigned and would like to have more points towards the maxv you can manually set 'max unchanged' mafv as higher value than the automatically calculated.

I see. It wasn't clear to me what was going on from the reading the Usage tab. Max Unchanged seems to default to the highest MAFv in the table.

Is there any consensus on why the datapoints are so close together in the low voltage area? My thinking in playing around with this was that I might want more datapoints when in open loop, which on my setup is generally the case above ~2.75V (aside from mashing the throttle at low RPM - maybe that's what the extra low-end points are there for?). Or maybe the flow characteristics and/or sensor characteristics are more accurately interpolated at higher flow, and more difficult to interpolate accurately at low airflow.

VGI pointed me to the thread. It was me who suggested the MAF rescale screen.

I would assume there is a reason that the OEM uses the original spacing, I figured it was the most accurate way to plot the exponential type curve that the sensor provides. There is definitely a need for accuracy at lower voltage ranges due to the requirements in closed loop operation and the cars work fine with the larger spacing in open loop ranges.

Now, my thoughts on how to use the rescale tool and why I suggested it:
MAFv points below idle (or lowest RPM point hit) are unnecessary, bar the lowest value, which I guess is a good reference value. Therefore you can remove these to allow for better resolution in the OL or CL to OL transition areas. I can only speak for the GT86 maps, but I'll assume that the other ROMs are similar, that at 2.5v the spacings suddenly increase. So I would set the max unchanged to 2.5v, this then adds the new data points above 2.5v and then scales down the spacings in the 2.5-MaxV value. Also, if you're not hitting 5v, it allows you to reduce the MaxV value which in turn increases resolution too.

Agreed; there are several cells on either end that are never hit, even more so because I have my idle speed bumped up due to a lightweight flywheel and crank pulley (and because I'm near Phoenix and otherwise the compressor just does not spin fast enough at stop lights on these 110 degree days, but that's another story and another tuning challenge).

I may play around with this feature some more once I get a known good scaling locked down.

Hey vgi -

So, I've been playing around with this tool and I have a couple comments / suggestions. Hope this is helpful.

A couple of bugs:
I often get an array index out of bounds error (200 >= 200) when loading a CSV file into the Open Loop tuning tab. As far as I can tell, the file processing still works when I get the error.

Also in the Open Loop tab, when prompted, if I choose to modify the filters when loading a CSV file, the file does not load (no error message).

And a comment:
At least in my ROM (02 WRX), there is a table called Minimum Primary Open Loop Enrichment (Throttle). This is a maximum AFR based on throttle position, and it has priority over the POL Fueling table. The stock value at above 88.8% throttle is 12.98. Now, my POL Fueling table, which I copy and pasted into this tool, contains values leaner than 12.98. This tool is not aware of this overriding AFR, which causes incorrect results.

For example, at load 1.04 and 2000 RPM, my POL table calls for 14.36. But I'm at 100% throttle when logging, so the ECU overrides this value and in fact targets 12.98. This scaling tool doesn't know that, so it sees my wideband AFR reading 13.0, compares to the POL table value, and thinks I'm rich by 10%. Of course, if I went ahead and made the suggested MAF scaling changes I would then be running lean.

There's an easy fix. Replace all values in the pasted POL fueling table that are leaner than the Minimum Primary Open Loop Enrichment at 100% throttle with that overriding target AFR (12.98 in my case). Should be pretty easy to implement in the tool to do this automatically as well.

There may be some other compensations that are applied to the fueling table that would introduce errors as well. The only one that is defined for my ROM is based on ECT, and has no effect at normal operating temps. I have heard some rumblings about added enrichment during spool-up, but I don't know which ECUs do that or if the tables have been found, so I'm not much help there.

Thanks again for contributing this tool.

EDIT: One additional suggestion is to add a variable delay between the ECU readings and the wideband reading. There is usually a delay of several rows, depending on the wideband location, and if not watched out for, will introduce large errors at the edge conditions. ie I mash the throttle, ECU readings indicate this new state, but the wideband is still seeing the exhaust gas from when I was cruising in closed loop at stoich.

And, one more suggestion: ability to select multiple log files at once in the open file dialog box, and have them all open in batch mode.

Thanks for the updates

these are soon to be out

PS are out

Does the zip download contain the very last updated version?

Also:

In the usage tab it says to log "Time", "MAF Voltage", "IAT", "CL/OL Status", "AFR Learning (LTFT)", "AFR Correction (STFT)", "AFR Stock Sensor", "Engine Speed", and "Engine Load".

Is this correct?

Time = Ignition total timing (degrees)
CL/OL Status = CL/OL Fueling
AFR Correction = AFR Correction#1
AFR Stock Sensor = AFR Sensor#1
AFR Learning = AFR Learning#1
Engine Load = Engine Load (calculated) or is it Engine Load (4byte)

Sorry if I am missing something obvious.

Time is 'Time (msec)' (this is the incremental timestamp added by the logger for each row of data, starting at 0 and expressed in milliseconds - not something you select to log)

For load, I use Engine Load (Direct) (g/rev). I'm guessing you're on a 32-bit ECU; 4-byte should be fine.

Thx matt.