Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   Long term trim experiences? MS3 (https://www.miataturbo.net/megasquirt-18/long-term-trim-experiences-ms3-84861/)

Reverant 06-17-2015 03:09 AM

The module is configurable. That means you configure what the digital output will be on either warmup or error. I have 14.7 for warmup and 7.5 on error, with minimum reported value set to 10 (this means that if the wideband reports lower than 10, the module will report 10). My errror trigger value is set to 8, so it will actually only trigger on an error.

DNMakinson 01-03-2017 04:36 PM


Originally Posted by JasonC SBB (Post 1240715)
Does LTT adjust the entire fuel table, or a single number?

So I am reviving this as I plan to play with it some. I have a set of questions on the MSEXTRA forum, but I get answers there on about half of my inquiries.

It appears to me that LTT is going to work similar to VEAL with manual or automatic writes. It also appears that it is writing on a bin by bin basis (256 different corrections).

To me, this is not as useful as a single number, created by some weighted averaging. That's because my use for LTT is to adjust for Summer vs Winter fuels.

I don't want only cells that have been recently touched to get updated. If the Soichiometric AFR has changed in the fuel, I want the entire fueling to adjust, not some of the cells.

Still, I have set up EGO to not come into play until 175F, as I do not want corrections during warmup to be recorded in the LTT table. I'm not wanting adjustment for bad WUE. That should be a separate issue.

I have also set EGO authority to "0" all across row for 27kPa, and then normal from 28kPa up. That way LTT will not try to adjust over-run cells. It will, however, try to update idle cells. This may not be needed as time there is brief before Fuel Cut occurs, but that is how I set it up. May change it later to see if that is an important set-up parameter.

I will post up some LTT tables:
Start will be all zeros.
Then see what happens after some drive time, with no write to Flash.
Turn off car and re-start and see if table 1 goes back to zero or not.

Settings (other than mentioned above on EGO parameters):

https://cimg9.ibsrv.net/gimg/www.mia...f076b5e4a0.png

DNMakinson 01-03-2017 07:06 PM

So, after driving home, this is Table 1:

https://cimg5.ibsrv.net/gimg/www.mia...8a750c0fbe.png

I suppose it turned RED because one cell changed (by -0.2%). As you can see, this is with the car still running. After I turned it off, then KOEO, the same table pulled up. Tomorrow, I am taking a different car to work, so I won't get a further update.

Unfortunately, my tune is such that only the one cell changed. I'm thinking I will change the Stoichiometric AFR from 14.7 to 14.4 so everything will be about 3% rich. Then we can see what happens with a poor tune or a changing system.

cpierr03 06-21-2021 01:50 PM


Originally Posted by DNMakinson (Post 1384539)
Unfortunately, my tune is such that only the one cell changed. I'm thinking I will change the Stoichiometric AFR from 14.7 to 14.4 so everything will be about 3% rich. Then we can see what happens with a poor tune or a changing system.

Necroing this a second time.... @DNMakinson, did you go any further in testing LTT? I'm not finding much data out there on it.

DNMakinson 06-21-2021 02:11 PM

I did not. Seemed complex, and hard to tell what state things were in. I think a good tune removes the need as well.

As an aside, (the original subject of the thread) I also do not use CEL for WB02 sensor checking... Why, because every time fuel cut comes on, the AEM goes to steady 18.2, which triggers CEL due to no fluctuation. Have not found a way around that.

WestfieldMX5 06-22-2021 04:27 AM

Maybe use a loop function to trigger the check engine light with 2 conditions (lower or higher than target) and duration for X seconds.
Not even sure if that's possible 'cause loops make my brain protest ... just thinking out loud.

DNMakinson 06-22-2021 07:44 AM

I’ve not found a way to include loops into CEL functionality.

deezums 06-22-2021 11:56 AM

More half-baked code from MS3. LTT and CEL both.

Someone could fix the CEL in the code, easy as adding a flag to cancel CEL flagging while in overrun or whenever EGO is conditioned off, but to do it they'd also need to step about 6 years back in time and through about 6 years of bullshit basic ass bugs and shitty code.

DNMakinson 06-22-2021 12:54 PM

@deezums Correct. I live with whatever is in 1.4.1, because I don't want the newer stuff. They finally fixed a LONG running bug where limp mode did not properly lower either boost cut or rev limit (I forget now which it was, but I won't upgrade to get the fix.

I suppose I could learn to code, and modify 1.4.0, but, really, what I have works Okay for me.

How is your Haltech coming? Is it treating you well?

deezums 06-22-2021 01:24 PM

Before I bent two rods it was going ok, still out of commission for the time being unfortunately. Didn't really have time to get into the fancier features just yet. Wish I had more time to play with the stock engine first, but I got tired of hitting boost cuts on the binding turbosmart wastegate and stupidly just raised the limit to "fix" it.

I know I loved the WUE taper, I have mine linked to RPM. No more deciding between running pig rich or idling wicked lean while cold.



All times are GMT -4. The time now is 08:56 PM.


© 2024 MH Sub I, LLC dba Internet Brands