Tuners Rejoice! Free Tuning For M4.4!


Recommended Posts

From what I understand your system Does not use a separate STFT and LTFT value that are only updated every X cycles or Y time units, but directly reacts on deviations of the requested AFR (closed loop). VE will always play a part since it's a mechanical reality. However, the way VE works in the narrowband software is that it is a correction factor to achieve stoichmetric fuel mixture rates without upsetting fuel trim, sort or long term. The way you describe it here is that you are no longer using the VE table for this correction, but are relying on the speed of the wideband system to correct for volumetric efficiency and use the VE table strictly for target AFR.

I am not questioning the robustness of your modification. I'm merely stating that if it would be topped up with a static VE table, it would be even more spot on without an O2 sensor, be it wideband or narrowband.

Unrelated, M4.3 narrowband diagnostics are clearly inferior to those in the M4.4. I am getting an error for the front O2 sensor, too slow (already spotted that myself, but didn't clean/replace it yet). The M4.3 I had in previously was totally contempt with this sensor. This should prevent situations where people with semi-failing narrowband sensors will get horrible driving cars with bad fuel economy.

  • Downvote 2
Link to comment
Share on other sites

I modified Piet's code to allow the stock VE table to function normally, albeit with an additional target AFR map which uses a wideband sensor as reference. I prefer this method since it gives additional control over the AFR. Setting the target AFR map is easy and once programmed it doesn't need to be revisited. To tune the VE table I turn off LTFTs and use a history table to record the STFT using the same map axes as the VE table. I then adjust the VE map based on the percent of deviation from the STFT

Link to comment
Share on other sites

In my opinion the extra target AFR map  only complicates matters unnecessarily.

When MAF and injectors are dialed in correctly the VE table is already close enough and only relatively small corrections by the wideband control (through the STFT) are necessary to get the correct AFRs, which make the method fast and accurate enough.

With my mod it's just filling in the desired AFRs in the VE table and that's it.

No need for extra tuning a table, or  making revisions.

Several people have tested my mod and it turned out to be quite accurate.

 

Theoretically it's correct to first get the VE table as close to the desired AFRs as possible without intervention of the fueltrims, after wich the fueltrims only have to do minor corrections reading from a separate table.

But in pratice it just doesn't add much  to precision and speed of the system,  while the necessary corrections of the fultrims without the extra table are already small enough.to get an accurate result.

 

EDIT: The whole idea of the WB mod is to simplify AFR tuning by just filling in the desired AFRs in a table (apart from being able to run higher AFRs at idle and light load then 14.7).

The extra table throws you back to tuning the VE table again,  but without real gains in speed or accuracy.

 

 

 

 

Edited by Piet
  • Upvote 1
Link to comment
Share on other sites

From what I understand your system Does not use a separate STFT and LTFT value that are only updated every X cycles or Y time units, but directly reacts on deviations of the requested AFR (closed loop). VE will always play a part since it's a mechanical reality. However, the way VE works in the narrowband software is that it is a correction factor to achieve stoichmetric fuel mixture rates without upsetting fuel trim, sort or long term. The way you describe it here is that you are no longer using the VE table for this correction, but are relying on the speed of the wideband system to correct for volumetric efficiency and use the VE table strictly for target AFR.

 

​That's not how it works at all.

With the mod, the VE still has its original function. Nothing is changed in the code to change that. So the first step in the process is to calibrate the maf and the injectors so the VE table is a good model for the reality (like it's supposed to). Only then the Wideband routine is installed. This routine merely takes its values from the VE table, but does not alter its function. It then looks at the current mixture and uses the stft to correct. So yes the stft function is also still in effect, only now its target point is varied by the wideband routine. The LTFT was also left functioning in our tests, but it hasn't got much to do if the hardware is calibrated correctly (as it should of course).

So if the hardware is calibrated correctly, then requesting a certain afr in the ve table already gets it in the ballpark even without the wideband control.
The wideband control then only has to make small corrections to make sure the target is met consistently and with precision
You could run the wideband mod without calibrating you stuff first and it will still work, only a little less effectively.

This way there is no need for a seperate VE table except for some special use cases where the VE table needs drastic changes to keep in line with reality.
This would be the case with a non standard maf curve shape for instance.
Having one table suffices for everyone using the standard maf curve shape (the maf factor does NOT alter the overall shape of the maf progression), and this saves you from having to alter two tables everytime you want to make a change.
95% of the people on here would fall in this category.

Edited by venderbroeck
  • Upvote 3
Link to comment
Share on other sites

@Avinitlarge: Some fault code information from Vadis. And I refuse to press shift+enter, so the rest goes here: Here are some more information from good-old Vadis:

EFI-45x-2.pdf

EFI-45x.pdf

EFI-112.pdf

VCC-052340 EN 2015-04-18-S90-Input-Signals.pdf

VCC-052341 EN 2015-04-18-S90-Control-Functions.pdf

VCC-052343 EN 2015-04-18-S90-OBD.pdf

  • Upvote 1
Link to comment
Share on other sites

So I accidentally installed the 608 Bin instead of the 607 on my automatic 98v70r  Just now realized it.. Would this be why when I boost the check engine light is flashing?

 

Also, do I need to change any settings to make sure my injection settings are right on my car with the 607 file?

​I would change to the 607 asap.

 

the original injector settings in both bins are for white injectors IIRC.  Can't see your sig so don't know what mods you have..

Edited by gdog
Link to comment
Share on other sites

@Avinitlarge: Some fault code information from Vadis. And I refuse to press shift+enter, so the rest goes here: Here are some more information from good-old Vadis:

EFI-45x-2.pdf

EFI-45x.pdf

EFI-112.pdf

VCC-052340 EN 2015-04-18-S90-Input-Signals.pdf

VCC-052341 EN 2015-04-18-S90-Control-Functions.pdf

VCC-052343 EN 2015-04-18-S90-OBD.pdf

​Thank you, I can't view the attachments, must be some issue with the new forum setup

Link to comment
Share on other sites

That link tells you the date and post number, I'm not sure how that doesn't help

​Post numbers seem to be non-existent now.

had to go searching for the correct link and fixed it. looks like a lot of links are broken now :\

​Thanks for your help!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share