Need help with BEN map

[JoshH]

I'm working on dialing in my virtual VE table for my LS3. I'm trying to follow Swingtan's tutorial, but I'm running into a lack of experience in regards to gas tuning. I am using an AEM UEGO 30-0334 that I have setup for logging directly through the V2 as a TCM. The problem I'm running into is I have no idea how to setup a BEN map, and the tutorial makes the assumption that you already know how to do that. I've tried searching, but I'm getting bogged down in all the data. Can someone provide or point me to the data I need to get this figured out?

[joecar]

Hi JoshH,

For the V7 scantool, you need the calc_pids.txt from post #191 here:

AEM-X-Series-OBDII-Wideband-UEGO-AFR-Sensor-Controller-Gauge (https://forum.efilive.com/showthread.php?26689-AEM-X-Series-OBDII-Wideband-UEGO-AFR-Sensor-Controller-Gauge&p=236919&viewfull=1#post236919)

[joecar]

you will need to log these pids:
- SAE.WO2S11
- SAE.LAMBDA
- CALC.WO2BEN (from the calc_pids.txt posted above)

[JoshH]

Thanks for the response! I ended up reading the auto ve tutorial and poking around on the forums and finally stumbling through enough to get it figured out. I’ve been making changes all day long, but it is taking a while to get it lined out. Do most tunes rely mostly on the MAF sensor? My virtual VE table was way off. It was going dangerously lean at higher RPM during power enrichment. I have made no less than 10 revisions, and it is still not really where it needs to be. How critical is it to getting it spot on? I guess I’m not sure the purpose of the table when the afr is running where it should before.

[joecar]

ECM does this:
- above 4000 rpm: uses only MAF,
- below 4000 rpm: uses MAF and/or VE below 4000 rpm (i.e. MAF for steady state, VE for transitions, and sometimes a blend);

ECM also uses VE for sanity checking the MAF.



Post tune/log files, and some screenshots of your steps/maps.

[JoshH]

Thanks for clarifying. That probably explains why my AFR readings were so erratic at lower RPM. I'm going to keep working on smoothing it up and getting it all dialed in right. What exactly do you need screen shots of?

[joecar]

Also, when correcting VE, you want to make sure that MAF is disabled...

you can be sure that MAF is disabled only when you see a MAF DTC... otherwise it is not disabled.



Screenshots of your BEN map and the VVE before/after applying the BEN map.




Also, are you applying the transient filter before applying the BEN map...?


Also, are you working in monotonic sub-slabs of VVE (i.e. curvature is in one direction only)...?

[JoshH]

I know I have the MAF sensor disabled because I pulled the wire out of the connector like Swingtan said to do in his tutorial. I emailed you some screenshots and logs and stuff to the email address you sent me yesterday. I'll be honest, I have no idea what you are talking about on those last two, so the answer is probably no.

On a slightly related note, last night I hooked my MAF sensor back up, re-enabled the STFTs, and put more of a normal tune back in. Now the AFRs are swinging very wildly again which they were not doing in SD mode.

[joecar]

Even with MAF wire removed, make sure a MAF DTC shows up... otherwise ECM computes what MAF should be and uses that.


The transient filter filters out any data frames where the data was changing... on the MAPs toolbar, there is a button for editing maps, and a button for applying the current map.


You should apply BEN map only to small sections of the VVE table, these small sections should have only one curvature (either concave or convex), not a mixture.

[JoshH]

I think I turned the MAF codes off, but I will re-enable them to make sure. I haven't been using any filters on the map, and I have been copying and multiplying the whole table. I guess I have a lot more work ahead of me. I will read up on the transient filters. Is it preconfigured into the map already, or is it something I need to setup? So should I try to focus my datalogs on one area of the map at a time? I have been trying to get 25ish minute long datalogs with a lot of varied MAP and RPM values to try to get the most thorough results. I may need to modify my method.

[joecar]

I think I turned the MAF codes off,but I will re-enable them to make sure.Yes, MAF DTC's must be enabled... either 1-Trip or Non-Emissions.

[joecar]

I haven't been using any filters on the map, and I have been copying and multiplying the whole table. I guess I have a lot more work ahead of me. I will read up on the transient filters. Is it preconfigured into the map already, or is it something I need to setup?
I don't remember if the transient filter comes preconfigured... let me pull it up so you can copy.


So should I try to focus my datalogs on one area of the map at a time? I have been trying to get 25ish minute long datalogs with a lot of varied MAP and RPM values to try to get the most thorough results. I may need to modify my method.
Yes, one region at a time... keep throttle movements slow and to a minimum, use the brakes to load up the engine if necessary.