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Author Topic: Statistical Load Bearing Dyno using ME7Logger.  (Read 10276 times)
carlossus
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Leon Curpa Stg1+


« on: December 21, 2011, 06:31:51 AM »

I've been thinking about his for a while and thought I'd get some discussion going.

Now we have setzi's logger with the capability to log high resolution data continually. Would it not be a fairly simple exercise to sample a large amount of driving data, say a few douzen hours of day to day use, then write some code to filter the data to extract data for specific load and RPM breakpoints?

With the right conditional filtering we could build up a virtual table of steady state loads for similar input conditions.

There is a LOT of information here about tuning for power and WOT response but less when it comes to low load / part throttle behaviour. I see this as a nice way to address this.

Anyone see this as a fun project?
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TTQS
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« Reply #1 on: December 26, 2011, 09:05:09 AM »

Hi carlossus.

I'm potentially interested in what you're proposing. My motivation would be to understand my Revo remap better, because it's not practicable or reasonable to reverse engineer it. Problems for me are that, while I recognise the power and simplicity of setzi's logger, it looks a bit too oriented towards hardened IT professionals Wink, although having grown up on early Windows and Unix command line inputs, that's not too much of an issue. Someone would have to help me in specifying variables to log.

Second issue is that until I get a new battery for my laptop, I can manage about 15 minutes away from a mains power source.

Third issue is that my code isn't stock. I have asked the question on the main thread for setzi's logger as to whether this would be a showstopper.

http://nefariousmotorsports.com/forum/index.php/topic,837.msg12182.html#msg12182

Good idea though and if I can support the effort, I will.

TTQS
« Last Edit: December 26, 2011, 09:33:23 AM by TTQS » Logged
carlossus
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Leon Curpa Stg1+


« Reply #2 on: December 26, 2011, 03:58:46 PM »



Something which could be useful in your quest to understand the Revo map strategy would be map tracing. This would also be possible by carefully filtered data.

In any case, I will slowly be playing about with data sets to see what can be useful.

If you haven't yet tried using ME7l you should. It certainly isn't for IT bods only.

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carlossus
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Leon Curpa Stg1+


« Reply #3 on: December 26, 2011, 04:03:15 PM »

 
I just noticed you used the word practicable. I had to smile because I have a feeling you have proabay had to deal with ALARP? Smiley

« Last Edit: December 26, 2011, 04:05:12 PM by carlossus » Logged
TTQS
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« Reply #4 on: December 27, 2011, 04:22:55 AM »

Hi.

phila_dot says I will have no problems using it which is encouraging and I spent a short time browsing the available variables yesterday which was impressive. I'll take a proper look soon and then delete the ones that won't be of much use, properly read the instructions then give it a whirl.

You're right, once I opened up the package and tried the GUI it didn't look too difficult to get to grips with.

ALARP is indeed quite close to my heart!  Wink

TTQS
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TTQS
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« Reply #5 on: December 31, 2011, 11:00:24 AM »

Please find attached my first log with setzi's ME7logger. This was done on a short drive moving through the gears and engine speeds so although there is some sustained high load operation, there is actually no clean WOT pull from just over idle to redline in there.

There were originally 127 variables as per the attached configuration file, but on review, I deleted those that were not useful (i.e. entire columns of the same number) and reordered some data so that the first 28 columns (indicated with pale yellow shading) contain some of the most commonly logged variables. I will probably prepare a new config file with only about 30 parameters in it for everyday logging.

I haven't done any analysis of the data yet but see what you make of it and what it can reveal about the Revo Stage 2 tune. I was surprised to see enrichment deployed in lamfa_w at high torque, especially in the light of recent discussions regarding using this for tuning and my general aversion to that. Perhaps I should start to prepare one of my hats for consumption...

TTQS
« Last Edit: January 01, 2012, 10:32:01 AM by TTQS » Logged
carlossus
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Leon Curpa Stg1+


« Reply #6 on: January 01, 2012, 05:29:20 AM »

Cheers for the log. The way AFR reacts looks very different to mine, I'll have to trake a much closer look when I can.

I just wondered if you have tried playing with EcuXplot yet?

http://www.nefariousmotorsports.com/wiki/index.php/ECUxPlot

Also, this morning I have been reading around for a decent open source data analysis suite.

http://www.ggobi.org/ looks very capable but is going to take some reading of the manual to get what I want. It crashes a bit too.

If you wanted to play with this you'll need to save your log as CSV with only the top row containing  the variable names (or descriptions) and all other rows just data.

I'll post back once I have anything useful.
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TTQS
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« Reply #7 on: January 01, 2012, 06:21:55 AM »

Hi Carl.

I haven't tried ECUx Plot yet. To be honest, everything has been done in a bit of a whirlwind over Christmas and New Year when I sort of suddenly realised that I had a small window of spare time to come on here again and start getting involved in interesting discussions, etc. Then I bit the bullet and started investigating setzi's ME7logger whereupon I twigged that with the GUI, it was simple enough for me to use.

After I had played about with it, I realised just how amazingly powerful it is. Then I ordered a cable which only came yesterday and I had about 20 minutes to get a log before going to a family get together!  Shocked

I'm 100% behind your idea of a statistical load-bearing dyno supported by real-world driving conditions and my motivation for that is to define/populate the common maps with Revo Stage 2 tuned data so that I can learn from a 'good' commercial tune and then feed that knowledge back in to my little tuning awareness document. As you comment, I agree that the part-throttle behaviour is just as interesting and important as WOT behaviour, particularly because I feel that the Revo Stage 2 on my car yields effective performance at part loads too, not just when mashing the throttle.

Anyway, the only thoughts I had last night were about filtering the raw data into a batch of three columns (for each x,y,z kennfelder obviously) then writing an Excel macro to sort it, populate an internal array, then interpolate it back to original axis sample points and write it to a table in a worksheet in the same format as in my tuning document. Then compare changes from stock to tuned parameters and attempt to understand why the particular changes have been made, etc.

I'm acutely aware though that it's not going to be straightforward to populate all zones of tables (e.g. low nmot, high load and high nmot, low load). Once we've dived in and had a play, we can kick around ideas on the way forward on this thread. I'm up for it! I had a quick look at ggobi. It certainly looks glossy but I reckon I can achieve my goal with Excel and a tidy macro.

TTQS
« Last Edit: January 01, 2012, 06:28:29 AM by TTQS » Logged
TTQS
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« Reply #8 on: January 01, 2012, 07:10:18 AM »

The way AFR reacts looks very different to mine.

Hmm. Yes. I see LAMFA being used to enrich down to lambda 0.89 (approximately "lean best torque at WOT") as nmot rises along the 100% mrfa line but since lambts_w is unity all the time, some other means is being deployed to reduce desired and actual lambda down to around 0.75 (approximately "rich best torque at WOT") as EGTs rise above 900°C. See comment here:

http://nefariousmotorsports.com/forum/index.php/topic,141.msg12421.html#msg12421

TTQS
« Last Edit: January 06, 2012, 07:05:39 AM by TTQS » Logged
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