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Plot and analyze your .csv logs


CasopoliS

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CSV LOG PLOTTER - online program

 

Airboy CSV ANALYZER - really robust Excel file

 

CSV Log Plotter (online):

This is a neat tool that allows you to analyze your .csv log and produce plots.

 

SAMPLE PLOTS (you can select which parameters to plot)

 

http://img444.imageshack.us/img444/5016/plot2zf.jpg

 

XY scatter - Boost vs. RPM

 

http://img207.imageshack.us/img207/706/plot25pe.jpg

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What I really like is that it calculates load... or comes close to calculating the same load as the ECU. I wonder why the ECU calculation is somewhat different.

 

Anyway, that'll help 2006 owners. I don't think anyone every did post the location for the 2006 load. And, that's one less variable for me to log.

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As a noob, I do the opposite. I have always logged it (because that's what the instructions says) so this is the first time that I have bothered to look at a spreadsheet calculated value.

 

It varies and is usually 1 to 2% off but can be as high as 4.6% off. It should be identical except for round off error since it is a derived value and is derived from the same ECU recorded values (rpm and MAF).

 

I think the answer lies in the sampling rate/interval. Internally, the ECU has access to much more instantaneous values for RPM and MAF. Calculating the load from data sampled at 0.2 second intervals results in jerky load plots. See attached. I think this can be smoothed out by deriving interpolated values for MAF between samples and then adding a small delay correction. Of course, you can just look at the graph and see the jerkiness...

 

Just a guess. Please correct me if I'm wrong.

 

Anyway, this is a nice spreadsheet. I don't know anything about tuning and what a tuner wants to see and how he wants to see it, but I'm going to use it as a starting point.

untitled1.thumb.jpg.72e7585fa0411a0ff1eea327ffcfcf88.jpg

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This is not anything mechanical with the car because any anomalies in the car would still be reflected in the engine load calculation.

 

The calculated load is definitely off by a small amount (a few percent at most). Mine is exagerrated because I am looking at a very narrow band of load between 2.1 and 2.7 g.

 

I am pretty sure this is due to the sampling rate. Every parameter is read at approximately 19 ms intervals. So, if I am recording 10 parameters, the parameters can be anywhere between 19 and 190 ms out of phase. If the parameters are read in the order that ECU explorer records them, then I think it would be a simple matter to write an interpolator to correct for the phase difference.

 

I plotted edmundu's load. His is smoother because his points are so far apart due to his big power. However, even in his, I see about a 2% error.

 

If you scale his plot from 2.1 to 2.7 then you will see a bigger difference.

 

BTW, do you use this excel spreadsheet a lot? I'm finding a lot of bugs in the VBA code especially if you don't run it exactly like the way the author uses it such as grab a .csv file from a different subdirectory. I think it could use some better error trapping.

untitled.JPG.8759a5d2df02c60e667da234740a2ab4.JPG

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  • 2 months later...

FYI. Airboy updated his spreadsheet. It's really good and I recommend everyone use it to overlay their datalogs on their rom data.

 

Also, I modified Airboy's spreadsheet to scale the load. For example, the stock timing tables only go to 2.5 grams load, but it would be nice to scale it to 3.0 grams load for stage 2. I used to modify it manually but a smooth scale would be nice for surface plots and for using ecuflash linear interpolation. If you guys use my function, please let me know if there are any bugs. I've already found one.

 

http://www.enginuity.org/viewtopic.php?p=16328#16328

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FYI. Airboy updated his spreadsheet. It's really good and I recommend everyone use it to overlay their datalogs on their rom data.

 

Also, I modified Airboy's spreadsheet to scale the load. For example, the stock timing tables only go to 2.5 grams load, but it would be nice to scale it to 3.0 grams load for stage 2. I used to modify it manually but a smooth scale would be nice for surface plots and for using ecuflash linear interpolation. If you guys use my function, please let me know if there are any bugs. I've already found one.

 

http://www.enginuity.org/viewtopic.php?p=16328#16328

 

thanks!

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Hogmeat, have you tried datalogging with enginuity? It has more defs than ecuexplorer so you can datalog turbo dynamics.

 

Also, if you are running a Cobb OTS map, ask someone with street tuner to give you the tables so that you can paste it into Airboy's spreadsheet. The spreadsheet is a lot more powerful if you have the map data.

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