Beginner needs help with LS2 (E38 controller) C6 Corvette

[kunta0908]

Brief rundown.

2006 C6 Corvette.
Vararam intake
MS4 Cam / Supporting Valvetrain
American Racing Headers / Full Exhaust
M6


Owned the car for about a year, work already done to the motor. Tuned by previous owner's installer as well.
Purchased HP Tuners Pro w/LM-1 wideband, licensed the PCM last week. Been trying to read into the basic processes since.

I am finding a lot of information on version 2.24, literature everywhere for the basics. I sat awhile confused as to where some of these mentioned tables are at in v3.0. Until just today I assumed that v3.0 renamed some things and I would have to search pretty deep to find what they have been changed to. Today I pulled up a sample tune from an LS2 GTO. It seems as if the GTO in v3.0 has the Primary VE table i was looking for, whereas my E38 processor does not. It has MAF calibration tables, but no Primary VE / Main VE table that most of the previous literature I had read about had mentioned.

I did however take the car out for a scan yesterday and on this "tuned" Corvette, saw KR popping up after 4800rpm. (This is without any modification to the tune at all. Pure scanning). This pushed me to go ahead and start the basic VE tuning procedure, basing my understanding from those two MAF calibration tables (Low and High). I also created a couple graphs in the scanner based on the MAF frequency. Single line graphs Airflow vs. Hz. This was prompted from an online guide to 3.0 basics.

Using the existing cam tune, I disabled the MAF, copied the octane tables, and flashed the PCM. Pulled the scanner up and reset the LTFT's. Started scanning and took it for a decent drive. Filled up the created graphs pretty well with numbers ranging from -23 in the low Hz range to +9 up top. Saved the file and brought my laptop in to evaluate. Now if I haven't already started doing things wrong, I believe it took quite the wrong turn here. From what I had read, from here I would take those numbers and pull up my editor to those same graphs. With - numbers I would add that value to the existing number in that cell. With + numbers, I would subtract that number from the corresponding cell. Finish, flash PCM, repeat process until I start seeing -5 - 0 - +5 in all cells hit. Sounds basic. Sounds a lot like the DHP tuner I worked with years ago on my GTP. The followup scan revealed that those minor modifications did not really affect anything at all. May have even made some cells farther from 0. Thats where i began digging for information again.

Correct me if I am wrong, but it seems as if this LS2 is quite different than other processors in regards to what I am trying to do, thus the lack of that Primary VE table? I believe the numbers in the tune are represented as raw numbers rather than a percentage, opposite of what the scanner is presenting me? So editing them from scanner graphs like i was doing is somewhat correct, but rather than adding/subtracting what i was seeing, I should be multiplying by those percentages? Please someone help me out with defining this for me.

I am in no way near editing past the VE tables yet, but with the wisdom of this board, I hope to have these zero'd out and begin moving on to logging with the wideband and moving forward to eliminating this KR I am seeing.

So if anyone can clear some of this up for me, I would greatly appreciate it. It seems as if every other sample tune I pull up has these Primary VE tables easy to find and pull up. Which would make it much easier to follow some of these tutorial's directions...

Included the base Cam tune I got the car with and the first couple of graphs i created for VE tuning purposes as per the 3.0 tutorial I have been studying.

[kevin87turbot]

Which tables are you tuning with LTFT data? If you disabled the MAF, then its operating on the parameters in the Virtual VE table. Is that the one that you're editing?

[kunta0908]

Where is the VE vs RPM vs Map, or the VVE tables for this processor in 3.0?

It's right where it should be when pulling up other sample files, but not there when I pull up this tune

[schpenxel]

edit-->virtual VE editor

[kunta0908]

Thank you. Found it.

I was preparing to use the eq-ve software I found on these forums, but I presume this is actually now incorporated after finding this vve table, which is awesome.

I have gotten my wideband hooked up and reading properly with hptuners and have successfully tuned my MAF in to near 0's across the board. Progressing onward, I am moving on to VE and am running into issues. I created a graph in the scanner for afr error % with column/axis matching that of the VVE table. Disabling the MAF, turning off ltft's, taking it for a scan came back with horrible -20's all over my cells with various amounts none better than -16. Took this information and copy/pasted special % into the vve table then hit the coefficient button and relflashed.

This resulted in not hardly any change at all. Still seeing horribly negative %'so and the car is continuing to struggle at idle with the maf disabled. Repeated the process twice now and am only seeing maybe 1pt differences each time. Am I doing something incorrect? Should I ditch the wideband and tune with the ltfts/stfts?

Thanks for the help

[schpenxel]

In the VVE editor, on the left hand side, there is a box that says "VE Mode" and there are options for manifold switch open, closed, DOD, w/o DOD.

You need to make sure you are changing both the manifold switch "closed" and manifold switch "open" tables (can ignore the DOD ones unless you're actually working on a vehicle that is using DOD).

Only one of these options is actually used on most cars, and it's NOT the one that opens by default. After you make your changes and hit calculate coefficients, select the entire table, copy it, change to manifold switch open, paste the values into the table that comes up, then hit calculate coefficients again. That will make both VE tables the same, which is what you want

Basically you're likely changing a VE table that isn't used. Changing them both will ensure you get the one that is used

Also keep in mind the first 10-15 mins after a flash will give horrible results while injector tip temp and intake valve temp work their way back to normalcy (they are reset after a flash). Don't use data until things settle down a bit or you will be wasting your time.

This is my best guess on what's wrong... if you're already making those two the same then ignore me

[kunta0908]

Perfect. I took my first log after I switched to VE tuning and applied it as you told me to, to the VE CONFIG tune I created right after finishing the MAF. Idle was immediately better. Not nearly as much surging and almost dying out. Took it for a decent drive, hitting as many cells as I could, and applied this log as well. I will see the results in the mornings log session.

One question. I set the maf fail to 0-high, and 16000-low. This threw a po102 code. I read that I'm looking for a po103. I can also still see maf readings on my pid. Am I actually in SD mode, and the po102 is sufficient? Or did I just screw the maf up and the computer is still trying to read it?

Btw, I verified in the tune that po103 wasn't disabled or anything.


Tyty

[schpenxel]

If you log "air calc mode" you can confirm how it's calculating airflow.

I'd set the min to 1 hz instead of 0. As long as you're getting 102 or 103 you should be fine. I've never seen both that I can remember, just one or the other (usually 102)

If you really wanted to get extreme you can remove one of the wires from the connector on the MAF to be sure it isn't doing anything.

Good to hear changing both VVE tables helped move things in the right direction

[kunta0908]

Maybe I spoke too soon... not getting much closer to 0 today.

Question.

Should I be logging "afr error vs RPM vs map" in number, or percentage? Or does that just determine how you apply that to the vve tables?

I have been logging in percentage, still seeing -10 through -15 percentages in a lot of areas after a few tweaks with paste/special/%. When I change to view as numbers I'm seeing what I guess is a numerical representation of those numbers, which looks pretty good in that format. -0.1's and -0.2's.

Just making sure I need to be trusting the percentages and not get my hopes up at the numerical view looking so close to 0.

Generally, how many paste/specials/% am I looking at to really start bringing things in line. I'm wondering if I'm working off of skewed data by starting my logging before the 20min window after reflash. Regardless, even if I'm falsely showing super rich numbers during logs, by correcting with the paste/special/% function, it should over correct to the lean side after a couple, not barely inch closer to 0....

Maybe I'm way off...

[schpenxel]

Are you running in open loop?

Mine is using EQ ratio error but it's in %, so I can only assume that is what you would need as well

Using paste special is only a starting point. You really need to look at trends and make changes to surrounding cells to keep the VE table smooth. Otherwise you end up with crazy peaks/valleys.

You also may be getting bad data from decel, transients, etc. that are hurting your progress

Do you have a log/tune/screenshot/something for us to take a look at? That makes things easier for sure

Are you giving it 15 mins or so of driving after each flash before you start recording data that you're actually going to use for corrections?

[kunta0908]

Yes, I verified open loop and speed density with the mass air sensor state pid, as well as the air calc pid you mentioned earlier, not to mention adjusting the tune closed loop enable ect.

I tried to cut out the bad data from decel in the DFCO fuel page of the tune.

Here is current tune for VE Tuning I have been working with, as well as a log i made after a few adjustment rounds.

[schpenxel]

Maybe I'm missing something. I did a quick AFR Error graph using the log you posted and got this:

kunta0908 VE Error.PNG

But when I look at the original tune you posted vs. the tune that was just posted.. the only areas that are changed are basically areas that you didn't get to at all in this log?

Original tune you posted:
kunta0908 VVE Old.PNG

Latest tune posted:
kunta0908 VVE New.PNG

The only areas changed are what I've drawn a circle around.. but the log you posted doesn't get to those areas at all.. which seems odd to me. Do you have a different log that hits these cells? The log you posted hits basically everything except these cells

Does your graph for AFR error look like mine or something else? There's no doubt most of your VVE table needs to be reduced by at least 10% across the board.. but most of yours hasn't changed? It's basically exactly the same from a week ago, no changes have been made in the areas that are off

Maybe I'm missing something, it wouldn't be the first time

[kunta0908]

Well that explains a lot. I'm logging afr error in a broader scale than what the vve table is setup for. Adjusted my column/axis on the graph, and all of a sudden I have much more data that lines up with the vve table. Thank you for pointing that out. Sorry for the silly errors and questions.

Now to go drain another tank of gas on the VE tune!

[schpenxel]

That would make sense. Hopefully you see progress now!

[kunta0908]

So the past week I have seen success in zeroing out my Maf, and proceeded to work on my VE tune with schpenxel's help. Tyty!

After a few long runs down to Galveston and back on I45, making corrections to the VVE table after each run, giving it 20min of runtime before scanning again, I think I finally have gotten quite close to acceptable VE tables!

Went ahead and loaded the corrected MAF and corrected VE tables into the original tune last night and made a few quick WOT pulls on the way home from work. KR is popping up as it was before I began touching the tune, but where I saw 5-6 degrees prior, I am seeing around 2, with hints of 3 spattered around. Understanding that these were not long pulls, only hitting 3400 rpm @ WOT. Are these inconclusive graphs? Am I going to need some max RPM pulls before I can go further? Or can I start with the data I have?

I went ahead and changed some knock settings as seen doing some research on the forums. Decay rate, base retard, base idle spark advance, afr correction, and IAT spark settings were modified. Weather is nasty right now, so unable to take the car out and test this out.

A few questions though. My PE EQ ratio is 1.146 across the board. I believe that translates to 12.75 afr? Should this be left alone or set a little leaner (have read that a good starting point for LS2's is 13.0)? If leaner is the way to go, should I set that first, then worry about timing to reduce any KR left on the table? Or go out and find my KR and pull timing in those areas to reduce it, and then lean out the PE EQ?

Lastly, Closed Loop Mode vs. Airflow and O2 Rich/Lean vs. Airflow tables. Have read some inconclusive threads about modifying these for better gas mileage and the such. Any experience with these tables on a big cam LS2? Could not find any supporting information on setting the O2 tables rather than guessing up and down, while modifying the CLM vs. Airflow table suggestion was merely inputting data from a successful tune on an 2001 Zo6. Would like to know if these suggestions can be taken into account for my platform or if there is a better way to calculating correct numbers for these.

As far as timing for cruising conditions, should i just log what cells I hit during normal cruise conditions and start to increase timing through those cells, or is there a generic portion of the table I can throw timing at to begin with?

Lots of questions, hoping to get some help wrapping my head around these basics. Thank you in advance!



Tune is included as an attachment. Scan file is linked from dropbox:

https://www.dropbox.com/s/1lnr8e4kq0...final.hpl?dl=0

[schpenxel]

1 / EQ ratio = commanded lambda
1 / 1.146 = 0.872 lambda

Commanded AFR would depend on what you are using for stoich.

If you're using 14.7 then 0.872 * 14.7 = 12.82

Or you can do it more directly as 14.7/1.146=12.82

Lambda is easier once you get used to it IMO

[kunta0908]

Yea. I'm running pretty near commanded afr through cruising conditions, afr error is within 0-1% aside from areas being modified by dfco. After a few runs with the knock tables modified, i am logging less KR, but still around 2 degrees max. this seems to be occurring at PE tip in. my TPS rolls to 100% and im still seeing a commanded 14.7 and a +10% error going lean. This is where the KR occurs. This only happens for a split second as the commanded goes to 12.8 a second later. Iva read that this can be addressed with transient fueling, but I dont even know where to begin with those tables

Should I just try addressing the kR with a reduction in timing? Or does anyone have an alternate idea to fix this?