Tuners Rejoice! Free Tuning For M4.4!


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23 minutes ago, Turboforslund said:

Hi,

Does the system still try to engage the clutch even if you disconnect the lowpressure switch?  If it doesn't measure a pressure in the system I think it will not even try to turn the compressor and therefor not make any idle compensations for it (an empty system means no lubrication).

// Turboforslund

Well, the system actually is empty (the one who inspected my A/C did so I could work on it myself), so it shouldn't even try to engage it in that case. The change is very apparent when I flip my A/C switch still, it hangs at 2k RPM when rolling out towards a traffic light, and almost stalls to 500RPM when @ idle I turn the A/C off.

I'll try disconnecting the switches though, will report back.

Edited by Boxman
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I'm having some issues with the WBO2 Regulation. My actual AFR follows my requested AFR closely at low loads but as soon as the turbo spools up it goes very rich to the point where it sputters and no boost builds. (under 10 AFR). My injectors are properly calibrated and I have no boost leaks. I tried a regular COP converted/MAF scaled 608_rev5b bin and the car has normal AFRs and boosts fine. The proper channel for my WBO2 is selected, WBO2 regulation is switched on, I have decreased the time for lambda readiness and I have even tried running it with fuel trims switched on/off all in an effort to see why my actual AFR is not following the requested AFR under higher load scenarios. 

I am also not able to get a knock count from the adx value VKRCOUNT. XFALMIT and FALLT both indicate timing reduction under boost (when using either the regular 608_rev5b tune or the modset with the WBO2 regulation. 

Any thoughts? 

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@Stefan Mohammed: Set all the load threshold lambda control values to max. Under Fuel Trims.

Set the LTFT values to 0 and set the STFT control ranges to theri + or - max.

 

That is the way to disable the WOT regulation and drive WB only. ;)

-edit and don't forget to set al the "tps value for wot detection" to 100.

Edited by razorx
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I have some questions about cam timing, which I have been trying to set through trial and error. 

- Is turbo chill (overlap slowing spool) noticeable in a log? I ask this because I advanced my exhaust timing a little, and from the log, it looked like my turbo started to spool a bit better.

- What's a bigger contributor to exhaust re-circulation, higher EGT and knocking?  Closing the exhaust too early or overlap?

- Is it possible my exhaust timing is too advanced if I'm getting codes about a damaged TWC and what feels like misfires?

I would like to hear if anybody has had some luck optimising their tune with iterative adjustment of their cams.

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Small question/feature request;

Is it possible and/or is there room in the bin to make the "Max TCV duty cycle limit" a RPM dependent table?

This would allow me some better control on overshoot situations, where the control software is simply too slow to tame the incoming rush of pressure as it spools up. The pilot table only helps so much when I punch the throttle around 3k rpm in second gear.

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Cant that overshooting be due to a too strong wg spring or a not very progressive tcv map?

You should be careful with the tcv dc values around the spool up area.

If you are having that overshooting the transition values should be as smooth as possible.

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The idea of an RPM dependent TCV duty cycle limit is to my opinion not a good idea.

I think so because M4.4 is capable of avoiding boost overshoots by it self. The TCV duty cycle pilot control table is ment for that purpose and takes the RPM and the current load into account. More than just RPM. To my opinion, a well adjusted couple of tables works very well.

But please tell me if I have missed something. ;)

You can tune that table easily if you follow these instructions:

 

Edited by razorx
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Well, before I started seriously tuning my car I just set the TCV duty cycle limit to 10% or so, so that I wouldn't damage my engine on the stock tune and that worked wonders in taming the thing.

I can see the controller at work in my logs - when I go full throttle at 3k RPM, the requested load is above actual load, and the controller tries to fix that by ramping up the TCV duty cycle, quickly hitting the global limit I set. Then as soon the turbo rushes in a second later, load overshoots and the software slowly turns down this maxed out setting. On my GT3071R this is simply too slow atm. I can see in the logs how it tries to controls it and it gets it in the end, but it always overshoots the mark initially - i need a drastically lower limit at 3k RPM to avoid this.

As I'm not by a long shot finished with mapping my tune (I do small iterations whenever I have time on the road, both to be careful and to properly teach myself the whole procedure), I don't want to go through the process of carefully managing my duty cycle map on every iteration as well - I'd just like to have the ability to put hard limits in place where I already know what max value I want it to be at, so that when i'm in the process of tuning (and thus don't know yet how the system will respond) I will be certain to avoid any damage. I've had some nasty overshoots combined with knock in my initial runs as I overshot into the 12ms load territory where I have not carefully setup my ignition map yet. When I've got the important maps down, I'll can go through the pilot TCV map properly and see if I can tune that properly.

tl;dr I don't want to have to tune everything at the same time when I'm still in the progress of tuning the fundamental maps (load req, AFR, ignition timing), when I already know how the TCV duty cycle should behave to avoid potentially damaging overshoots.

6 hours ago, Piet said:

Interesting idea !

Yes, that's possible.

Great! Let me know if we can work something out to try this :)

 

Edited by Boxman
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On 6/22/2016 at 4:34 AM, razorx said:

 

@Stefan Mohammed: Set all the load threshold lambda control values to max. Under Fuel Trims.

Set the LTFT values to 0 and set the STFT control ranges to theri + or - max.

 

That is the way to disable the WOT regulation and drive WB only. ;)

-edit and don't forget to set al the "tps value for wot detection" to 100.

Doesn't work :dry: I'm stumped on this one. It follows the requested AFR almost perfectly at low load. I boost leak tested the car and there are no boost leaks. As I said it works perfectly off the VE map in a regular 608_rev5b. Any other thoughts?

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2 hours ago, venderbroeck said:

Boxman, are you using the boost threshold mod?

I don't think I am, then again I'm not actively logging boost other than my IPD gauge either.

Anyway, santa came early, Piet actually wrote the mod a few hours ago and I had the privilege of testing it. Pictures speak a thousand words, this was after only 2 tries setting it up (1st try testing if it worked at all at lower loads, second try setting it up for my full-throttle pull)

OFgLYSV.png

2N499AA.png

 

I set the TCV table to allow initial spool to begin at very low RPM <2500, gave it about 25% maximum in between 2500 and 4000 RPM and let it steadily rise up until my current maximum of 60%. 

Given it's simplicity I'm pretty happy with these first results. Granted, my tables are not neatly tuned at all, but at least this gives me the ability to run my tuning iterations and smooth out my maps without having to worry about the turbo going absolutely bonkers at 3500 RPM. High RPM behaviour is not affected while spool-up can be nerfed as per preference.

Thanks Piet, for this quick implementation!

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