newb tuning question

[08z06]

I recently had my LS7 Heads reworked by Lingenfelter and am in the process of adjusting my VVE maps to match the adjusted airflows. The CNC program was done on the heads so they flow better. I am planning on following the Virtual VE tutorial that EFI Live has put together. I'll do this with the MAF disabled. I am not sure what else I need to do with this other than adjusting the main VVE Table (B8101). After I am done I plan on turning my MAF back on. I want to run the car as if it's still in control, but adjust the B8101 table to match the new flow of the heads. I will also adjust the Power Enrichment tables so I am running a little leaner (12.6) from the stock settings. I'll end up logging this to be sure I am safe.

Questions:
1) is my plan of attack reasonable?
2) Do I need to adjust the closed loop VVE table (B8102) at all?
3) I figured my MAF was OK since I didn't adjust it or the intake? Do I need to re-tune my MAF? If I did this I would disable change the B8024 and B8025 figures so that it never referenced the VE tables. Then use the WB BEN values to adjust both B1097 and B1098. Reasonable?
4) Any other steps I am missing?

[08z06]

crickets

[joecar]

I recently had my LS7 Heads reworked by Lingenfelter and am in the process of adjusting my VVE maps to match the adjusted airflows. The CNC program was done on the heads so they flow better. I am planning on following the Virtual VE tutorial that EFI Live has put together. I'll do this with the MAF disabled. I am not sure what else I need to do with this other than adjusting the main VVE Table (B8101). After I am done I plan on turning my MAF back on. I want to run the car as if it's still in control, but adjust the B8101 table to match the new flow of the heads. I will also adjust the Power Enrichment tables so I am running a little leaner (12.6) from the stock settings. I'll end up logging this to be sure I am safe.

Questions:
1) is my plan of attack reasonable?
2) Do I need to adjust the closed loop VVE table (B8102) at all?
3) I figured my MAF was OK since I didn't adjust it or the intake? Do I need to re-tune my MAF? If I did this I would disable change the B8024 and B8025 figures so that it never referenced the VE tables. Then use the WB BEN values to adjust both B1097 and B1098. Reasonable?
4) Any other steps I am missing?
1) Yes. Do you have the VVE Tutorial and The VVE Guide (by swingtan/Simon)...?
2) I'm not sure, but wouldn't you copy B8101 to B8102...? (how are you planning to correct B8102...?)
3) You should correct the MAF since the MAF is affected by ANY change between the air cleaner/filter and the valves in the heads. Yes, you want to disable VE and CL and use WB to correct both MAF tables.
4) Check the PE TPS Enable, make sure it is not too tight or too loose. Also might have to do some idle tuning also.

Try to avoid thinking in AFR (can you say what the stoich AFR of your current fuel tank is...?) You want PE set to EQR 1.167 (this is leaner than EQR 1.175, and much leaner than the factory, but first make sure VE and MAF are correct).

What commanded fuel pid are you logging (SAE.LAMBDA)...? Make sure it behaves correctly.
What wideband lambda pid are you logging (EXT.WO2LAM1)(which wideband do you have).
Create a BEN calc pid using those two pids.

[08z06]

1) I do have the guide and planned on following that for tuning the VVE tables.
2) I wasn't sure of the B8102 tables were active given that B8026 (Intake Manifold Tuning Valve Option) is set to NO. I figured the B8102 table wasn't active. Am I wrong here?
3) I plan on doing this per the VVE Tutorial. I will log External Wideband* EQ to get my BEN factor to apply to the B1097 and B1098 tables. I'll have to run this twice to get each table right? Lock it in "low flow" and "high flow" separately to get the tables hammered out?
4) Are you referring to the B1056 table? I was going to adjust these down lower and increase the B1057 factor (Mode MAP threshold) so that PE was enabled above a certain MAP pressure. Where should I adjust idle tuning from B1848 and B1847? I figured if I corrected VVE's and the MAF it would adjust accordingly so my Idle tuning would be ok. Is that not the case?

Correct on the commanded and measured AFR/Lambda Pids. How do I go about entering a calculated PID? I tried to look that up but it appears I have to do it through notepad and the
calc_pids.txt file?

Thanks in advance for the assistance!!! I really appreciate it.


1) Yes. Do you have the VVE Tutorial and The VVE Guide (by swingtan/Simon)...?
2) I'm not sure, but wouldn't you copy B8101 to B8102...? (how are you planning to correct B8102...?)
3) You should correct the MAF since the MAF is affected by ANY change between the air cleaner/filter and the valves in the heads. Yes, you want to disable VE and CL and use WB to correct both MAF tables.
4) Check the PE TPS Enable, make sure it is not too tight or too loose. Also might have to do some idle tuning also.

Try to avoid thinking in AFR (can you say what the stoich AFR of your current fuel tank is...?) You want PE set to EQR 1.167 (this is leaner than EQR 1.175, and much leaner than the factory, but first make sure VE and MAF are correct).

What commanded fuel pid are you logging (SAE.LAMBDA)...? Make sure it behaves correctly.
What wideband lambda pid are you logging (EXT.WO2LAM1)(which wideband do you have).
Create a BEN calc pid using those two pids.

[joecar]

You are correct, you only need to tune the one VE table that is active.

[joecar]

B1097 and B1098: you can make two maps and run one log (make sure you cover sufficient MAF range)(also remember, steady progressive throttle gives better data than sudden/snap throttle).

[joecar]

There are some idle tuning threads here, I'll find suitable ones (altho the same concepts follow across ECM types).

[joecar]

Which pids are you going to use for Lambda/EQR...? Probably SAE.LAMBDA (log it and check whether it behaves like Lambda ) and EXT.WO2LAM1 (which wideband do you have...?).

Note that any of the BEN pids in any of the tuning method may be replaced with this BEN pid (or variations of it):

WO2BEN = {EXT.WO2LAM1} * {GM.EQIVRATIO} = {EXT.WO2LAM1} / {SAE.LAMBDA}

( this nicely avoids AFR pids )

( but make sure SAE.LAMBDA behaves like Lambda and not EQR )

[08z06]

thanks for the help. I logged some BEN factors for my MAF last night and was pretty lean. Some of my BEN Factors were around 1.45 at various frequencies... I only logged from 2050-2800HZ. I plan on getting it to run around stoich before running it on the street.

[joecar]

Post log files.

[08z06]

you will notice the EXT.O2.LAMBDA reading reads 1 for a while. It was still warming up. I ran through it quickly.. this was more of a test than anything (at idle)

18320

[08z06]

and wow... I just modified the B8020 and B8021 tables and it made my VVE table look terrible. I don't even feel comfortable throwing that in my car after the modifications it makes to the coefficients. What do you do there?

Edit: Nevermind, I am leaving my B8020 and B8021 tables. They hit all the RPM's and kPa's in the VVE table. I'm going to apply BEN Factors and see where it gets me.

[08z06]

Well, I am finding that when I disable the MAF and run my car it leans out quite a bit. I was driving and would see 16-18AFR depending on the speed and throttle. Also, my idle is ramping up and what not. I put my stock tune back in and my LTFT's were up around 27%.

I am worried about driving my car when its that lean. I'm not hammering it of course, but that's pretty lean. Suggestions?

[joecar]

you will notice the EXT.O2.LAMBDA reading reads 1 for a while. It was still warming up. I ran through it quickly.. this was more of a test than anything (at idle)

18320Looks like SAE.LAMBDA just stays at 1.000... do you have any logs showing it moving...?

Also, simultaneously, also log E38.AFRATIO_DMA.

[joecar]

The logged pid GM.FTC does not look right (value is 37...?).

[08z06]

The logged pid GM.FTC does not look right (value is 37...?).

I am not sure why it's reading 37 honestly. How do I go about diagnosing that issue? What shoudl it be reading?

Can you lock out the engine to run off maf only? Or does it always reference the VVE table.

[joecar]

I am not sure why it's reading 37 honestly. How do I go about diagnosing that issue? What shoudl it be reading?

Can you lock out the engine to run off maf only? Or does it always reference the VVE table.The dynamic airflow threshold RPM is set in B8024 and B8025

when rpm reaches/exceeds B8024, MAF-only is enabled; when rpm falls below B8025, MAF/VE is enabled;

MAF-only: MAF is used always.
MAF/VE: MAF is used during steady airflow/throttle, VE is used during transient airflow/throttle.

MAF/VE mode is aka dynamic airflow mode.

To disable VE, set B8024 to 400 rpm, and B8025 to 300 rpm.

[08z06]

how lean is too lean when driving to collect data?

[08z06]

new SD tuning file.... looks much better... my idle needs some work though,

18324

[08z06]

Well, I got the VVE tables reading pretty good. Started on the MAF and my idle speed has been jacked up. I assume that is because my MAF is now reading a lot more air at idle and after adjustments I dropped those values? I was planning on editing the minimum airflow table for neutral and park. Thoughts?

[08z06]

Idle is hammered out, but when I blip the throttle it takes way too long for the RPMs to drop. They are hanging. I was adjusting the throttle follower decel. rates, but i've doubled those values and it's not fixed. What can I log to determine what they need to be? Suggestions?

[08z06]

Idle is hammered out, but when I blip the throttle it takes way too long for the RPMs to drop. They are hanging. I was adjusting the throttle follower decel. rates, but i've doubled those values and it's not fixed. What can I log to determine what they need to be? Suggestions?


Ok, here is what I found. The idle issue was a result of the minimum idle airflow table. I adjusted these and things started to settle down.

One issue I just realized was that my Long-Term Fuel trims are up around 24% and they shoot up quickly at idle. I reset LTFT's at idle and watched them shoot up. When I did Speed density tuning and the MAF tuning I had them disabled. Any ideas why they are so out of wack now? How do I get these back into check?

I think it occurs at idle, which was my issue before. At cruzing speed my WBAFR gauge stays around 14.63, which is great. At idle and lower RPM's there isn't enough fuel. Would the MAF and VVE tables not correct the fuel requirements? I am thinking the MAF/Min Idle Airflow Rates have something to do with this. Curious of your thoughts and how I can resolve.

[08z06]

Well, I got it figured out. Got my VVE table dialed in to within 0.5% either way of stoich. After that I dialed in the MAF. The MAF tuning fixed my LTFT's. Now they are reading, on average, between 0 through -4.5%. I think I am in business now. Still need to tune the PE on the dyno, but that's for another day. For now I have it commanded to 13.5 or so.

Thanks for the help JoeCar

[joecar]

Good job :cheers:... (it drives home that large LTFT's are an indication of the prevalent air table (MAF or VE) being out).

Post before and after tune files so I can take a look (and learn something)... :)

[08z06]

I'll get them posted for learning material.

With my MAF and tuning tables updated I re-enabled all the sensors and maps. My Wideband AFR Gauge is reading VERY close to 14.83 nearly constantly. At idle it doesn't even move. This is as intended correct?

[joecar]

...

With my MAF and tuning tables updated I re-enabled all the sensors and maps. My Wideband AFR Gauge is reading VERY close to 14.83 nearly constantly. At idle it doesn't even move. This is as intended correct?Yes, that is what tuning does.

[08z06]

wanted to make sure that the car WANTED to command to Stoich at all times, except for power enrichment. THat was my understanding but never read it anywhere.

[joecar]

...

With my MAF and tuning tables updated I re-enabled all the sensors and maps. My Wideband AFR Gauge is reading VERY close to 14.83 nearly constantly. At idle it doesn't even move. This is as intended correct?


wanted to make sure that the car WANTED to command to Stoich at all times, except for power enrichment. THat was my understanding but never read it anywhere.

Ah, I see what you're saying (I had latched onto the words "nearly constantly").

What Lambda does SAE.LAMBDA report...?

What Lambda does the wideband report...?

What wideband do you have (what does it assume for stoich AFR)...?

What fuel are you running (what is the alcohol % content)...?

What is the stoich AFR set in your tune...?

Post a log file showing this.

[08z06]

What Lambda does the wideband report...? around 14.83

What wideband do you have (what does it assume for stoich AFR)...? TechEdge 3A1... it would be close to 14.83.. I'd have to check the programming.

What fuel are you running (what is the alcohol % content)...? 10% Ethanol 93 Octane

What is the stoich AFR set in your tune...? close to 14.83.

see info above

[statesman]

Why did you set your stoich AFR to 14.83?

[08z06]

I didn't, I tuned to 14.63. My guess is that my wideband controller is reading to 14.7 and I have 14.1 stoich 10% ethanol in the car. I will need to modify the calibration of my wide-band and see where i am sitting.

[08z06]

actually, now that I think of it I tuned to a 1.0 lambda on the tables but had to use a commanded AFR because I couldn't find a commanded Lambda PID. I have a bit of error in my tune. It's contradictory since I tuned to a 1.0 lambda, the AFR gauge used 14.7 stoich, so in theory by using 14.1 stoich gas I should be running a little lean. This doesn't match up with my long term fuel trims. I'll have to log to compare.

[joecar]

What Lambda does the wideband report...? around 14.83

What wideband do you have (what does it assume for stoich AFR)...? TechEdge 3A1... it would be close to 14.83.. I'd have to check the programming.

What fuel are you running (what is the alcohol % content)...? 10% Ethanol 93 Octane

What is the stoich AFR set in your tune...? close to 14.83.

see info above


see info aboveNo, I'm asking to see Lambda, not AFR ( lambda is regardless of AFR )

If your tune is set to AFR 14.83 and your wideband reports AFR 14.83 then your air modelling is good if the tune's stoich AFR is the same as the fuel's stoich AFR and as the wideband's stoich AFR... so let's use Lambda for this very reason (3-way assumption of stoich AFR).

[joecar]

I didn't, I tuned to 14.63. My guess is that my wideband controller is reading to 14.7 and I have 14.1 stoich 10% ethanol in the car. I will need to modify the calibration of my wide-band and see where i am sitting.


actually, now that I think of it I tuned to a 1.0 lambda on the tables but had to use a commanded AFR because I couldn't find a commanded Lambda PID. I have a bit of error in my tune. It's contradictory since I tuned to a 1.0 lambda, the AFR gauge used 14.7 stoich, so in theory by using 14.1 stoich gas I should be running a little lean. This doesn't match up with my long term fuel trims. I'll have to log to compare.You are supposed to set the commanded EQR (or Lambda) and tune the air tables (VE and MAF)...

post your tune file and a log file...

the commanded Lambda pid is either (whichever one responds correctly) SAE.LAMBDA or 1/GM.EQIVRATIO or E38.AFRATIO_DMA divided by B3671 (from your tune file).

[joecar]

Commanded fuel tables:
B3618 (PE)
B0141-4 (OL)
B0138 (Cranking)