Wideband VE Tuning Questions

[C10Racer]

Bear with me here; this is my first time with this specific kind of tuning and my first shot at LS Motors (lots of carb/mechanical injection experience as well as various other kinds of electronic injection). The car is an '04-base model/M6 Vette with Tsunami cam, headers, full exhaust.
1) Turn off items during VE tuning or not? It seems harmless to turn off COT, DFCO & LTFT but I've heard people go both ways on turning off PE & MAF. It seems leaving the MAF on would cause unwanted compensation when trying to adjust the VE tables?
2) If I want to tune with a wide-band and take out one of the front O2 sensors to install it won't that screw up STFT thereby negating any efforts at VE tuning? If you're tuning VE based upon STFT the front O2 sensors both have to be in, correct?
3) My answers may come from the first two questions but it seems my VE changes (based upon the STFT - RPM-MAP table) throw the fuel trims way in either direction but never close to the middle. I'm using the "multiple by half percent" special paste but I can't seem to nail anything down.

[5FDP]

1. I disable those things when tuning, nothing wrong with that. Correct you can not leave the MAF on while tuning the VE, it's going to skew everything and it won't be running solely off the VE like you need it to.

2. If you are using the wideband don't even use fuel trims at all. It would just make everything worse. The purpose is to tune the VE in open loop only with only the wideband AFR or lambda error making the corrections. Once the VE is dialed in with the wideband you can enable the trims again and see how it acts. You can make further corrections from there if need be.

[C10Racer]

1. I disable those things when tuning, nothing wrong with that. Correct you can not leave the MAF on while tuning the VE, it's going to skew everything and it won't be running solely off the VE like you need it to.

2. If you are using the wideband don't even use fuel trims at all. It would just make everything worse. The purpose is to tune the VE in open loop only with only the wideband AFR or lambda error making the corrections. Once the VE is dialed in with the wideband you can enable the trims again and see how it acts. You can make further corrections from there if need be.

1) That made the most sense to me too but I wanted to be sure; anything else you'd suggest turning off?

2) If you're tuning in open loop then the wideband would be preferred, correct? Just like PE tuning? I feel like the more I'm looking at sensors not filtered by the ECU (like STFT) the better chance I have of getting good data.

[Codes]

You have pretty much got it. Use your wide-band to tune, turn off fuel trims, tune the VE and the maf separately as 5F has said, once they are dialed in enable the mode you are going to run in, then re-enable fuel trims.

Personally I don't turn off PE as it is there for safety, you can set up a data filter to filter the PE.

[C10Racer]

You have pretty much got it. Use your wide-band to tune, turn off fuel trims, tune the VE and the maf separately as 5F has said, once they are dialed in enable the mode you are going to run in, then re-enable fuel trims.

Personally I don't turn off PE as it is there for safety, you can set up a data filter to filter the PE.

So you're saying manually disable the the ST & LTFTs then dial in VE with a wideband?

I know a lot of tuners only use the wideband for PE but you've A)got to tune in wideband for PE anyways and B)going to be tuning in open loop then why not just use wideband? You'll obviously tune the MAF in closed loop but that can be done after VE and PE, correct?

I am not planning on disabling PE so much as not getting into it and discarding any data which is affected by it.

[5FDP]

I actually tune both the VE and MAF in open loop only. I want zero corrections being made by the computer and trusting that my wideband is accurate. Then once complete I re-enable the MAF/VE and run the dynamic airflow settings like factory and see how the vehicle runs with fuel trims back on.

[C10Racer]

I actually tune both the VE and MAF in open loop only. I want zero corrections being made by the computer and trusting that my wideband is accurate. Then once complete I re-enable the MAF/VE and run the dynamic airflow settings like factory and see how the vehicle runs with fuel trims back on.

I actually haven't looked because I hadn't considered it but is there a manual way to turn STFT off or it a matter of putting a sensor out of range? So, when you tune the vehicle you're eliminating all inputs and tuning the base VE, then the MAF & then the PE. Then seeing what additional inputs are needed and turning those back on? That's a very logical way to do it and probably explains why I've been overshooting my VE targets with every change. Thanks a ton for your time!

[5FDP]

STFT should be just a enable/disabled under the open/closed loop tab. LTFT you'd set to like 284 degrees and then the closed loop enable temp you'd max out as well.

[Codes]

So you're saying manually disable the the ST & LTFTs then dial in VE with a wideband?

I know a lot of tuners only use the wideband for PE but you've A)got to tune in wideband for PE anyways and B)going to be tuning in open loop then why not just use wideband? You'll obviously tune the MAF in closed loop but that can be done after VE and PE, correct?

I am not planning on disabling PE so much as not getting into it and discarding any data which is affected by it.

Yes disable fuel trims otherwise they will skew your lambda error graph you have setup for the wideband as they will be continually correcting for lambda 1 and your wideband error graph will show little error.

Tune both the VE and the Maf using your wideband.

[Picklito]

What's the cleanest way to turn off MAF in this scenario? Not trying to hijack, but I'm doing the exact same thing. Thx.

[5FDP]

What computer?

GEN 3 just set the MAF fail high under the engine diag tab to 0hz, then set the 3 MAF dtc's to MIL on first error. Log MAF fail status in the scanner to make sure it says failed and remove all MAF related channels to prevent skewed information.

GEN 4, set the MAF fail high to 2hz, low fail to 1hz and the 3 MAF dtc's to MIL on first error. Do the same steps with status and channels listed above. That normally works, sometimes the low fail setting needs to be a higher number to fail the MAF.

[Picklito]

Thanks for the thorough answer, 5FDP, despite my stupidity. 05 P59 truck. And C10Racer, thanks for the great thread! I'm following...

[02Ls1]

Does anyone here have a layout (cfg) for tuning VE in speed density? I'm trying to set up mine but having problems.

[orripid]

Bear with me here; this is my first time with this specific kind of tuning and my first shot at LS Motors (lots of carb/mechanical injection experience as well as various other kinds of electronic injection). The car is an '04-base model/M6 Vette with Tsunami cam, headers, full exhaust.
1) Turn off items during VE tuning or not? It seems harmless to turn off COT, DFCO & LTFT but I've heard people go both ways on turning off PE & MAF. It seems leaving the MAF on would cause unwanted compensation when trying to adjust the VE tables?
2) If I want to tune with a wide-band and take out one of the front O2 sensors to install it won't that screw up STFT thereby negating any efforts at VE tuning? If you're tuning VE based upon STFT the front O2 sensors both have to be in, correct?
3) My answers may come from the first two questions but it seems my VE changes (based upon the STFT - RPM-MAP table) throw the fuel trims way in either direction but never close to the middle. I'm using the "multiple by half percent" special paste but I can't seem to nail anything down.

You can use long term fuel trims or a math short term plus long term, Or just use wide band and AFR err.
You install the wideband in the xpipe before the cats in its own bungie. If you dont have one then get one and install it run 1 output wire to a guage inside cabin and the second line goes to hptuners for tuning, well worth the 225$ Innovative LC-2 works great.

I do a maf only tune first with long term trims then turn off fuel trims and do wideband wideband using AFR Err (add extra fuel to the high tables before going WOT


Anyone needs help email me and i will send you the charts