LS3 tuning help needed

[K Rob]

okay - so i got all my knock retard removed - need help getting fuel trims closer to +/- 5%. Any help would greatly be appreciated.

2014 Chevy SS AT - Kook's LT's no cats, Rotofab CAI, LS7 maf, flex fuel sensor

[B52bombardier1]

Why no LTFT in your log file? My fuel trims were also crazy to the minus scale once upon a time with my LM7 and it turned out to be my cold air intake. I tried everything but once I put my K&N straight onto the throttle body, LTFT & STFT settled down to plus and minus zero where they should be. All I could figure was that the tubing caused chaotic air to reach the MAF screen.

Rick

[village_idiot]

You still have a degree or 2 of KR throughout most of your rpm range in the log you posted

Start by forcing it into MAF only mode, and tuning the MAF fueling part throttle up to 4-5000rpm using fuel trims. That will get part throttle closer. Do you have a wideband? You'll need one for WOT MAF tuning, and for VVE tuning after that

[K Rob]

I somehow forgot to save my last log after removing the final kr - so this is the last saved log.

[K Rob]

I don't have a wideband yet

[K Rob]

Why no LTFT in your log file? My fuel trims were also crazy to the minus scale once upon a time with my LM7 and it turned out to be my cold air intake. I tried everything but once I put my K&N straight onto the throttle body, LTFT & STFT settled down to plus and minus zero where they should be. All I could figure was that the tubing caused chaotic air to reach the MAF screen.

Rick

not sure why no ltft's

[village_idiot]

K Rob, post the latest revision of your tune file. I will set it into MAF only mode, and check to see why you have no LTFT's

Do you know how to open a compare file, to reverse the changes made to the file?

Are you familiar with tuning the MAF vs fuel trims?

[K Rob]

K Rob, post the latest revision of your tune file. I will set it into MAF only mode, and check to see why you have no LTFT's

Do you know how to open a compare file, to reverse the changes made to the file?

Are you familiar with tuning the MAF vs fuel trims?

yes - i know how to open & compare files
i am not familiar with tuning the maf & fuel trims

[crew chief]

Go to Engine>Fuel>Oxygen Sensors>Long Term Fuel Trims and change Min ECT to 45C to re-enable LFTF's

[K Rob]

Go to Engine>Fuel>Oxygen Sensors>Long Term Fuel Trims and change Min ECT to 45C to re-enable LFTF's

Thank You - any reason these would be turned off ?

[village_idiot]

2014ChevySStune - helping on hpt forum.hpt

Here is a file to get you started tuning the MAF side of the fueling. Pull this up with a compare file of your last tune to see all changes, but the important ones are...

- VERY IMPORTANT.... PE set to not come on until above 5000RPM. Careful with this, this is for part throttle tuning only. Keep throttle below 50-60% and RPM under 5000. This is only set this way until part throttle fuel trims are good. Do not go WOT like this.

- DFCO is turned off. Again, this is only because it affects fueling.

- Dynamic Airflow is disabled, and set to MAF only

The idea with this file is to gather part throttle data on fueling of MAF vs LTFT, and get the part throttle fuel trims closer to where they need to be. After this, you will need a wideband, and move on to WOT tuning of the MAF and then tuning of the VVE tables.

PS - Somebody has tuned this car at some point, and as pointed out above, they set the Min ECT on the LTFT above what the engine temp runs in order to turn them off. Some tuners do this because the LTFT's can make changes to your WOT fueling. I wouldn't worry about that right now. Let's focus on part throttle MAF tuning first, then move on to VVE tuning with a wideband.

[K Rob]

2014ChevySStune - helping on hpt forum.hpt

Here is a file to get you started tuning the MAF side of the fueling. Pull this up with a compare file of your last tune to see all changes, but the important ones are...

- VERY IMPORTANT.... PE set to not come on until above 5000RPM. Careful with this, this is for part throttle tuning only. Keep throttle below 50-60% and RPM under 5000. This is only set this way until part throttle fuel trims are good. Do not go WOT like this.

- DFCO is turned off. Again, this is only because it affects fueling.

- Dynamic Airflow is disabled, and set to MAF only

The idea with this file is to gather part throttle data on fueling of MAF vs LTFT, and get the part throttle fuel trims closer to where they need to be. After this, you will need a wideband, and move on to WOT tuning of the MAF and then tuning of the VVE tables.

PS - Somebody has tuned this car at some point, and as pointed out above, they set the Min ECT on the LTFT above what the engine temp runs in order to turn them off. Some tuners do this because the LTFT's can make changes to your WOT fueling. I wouldn't worry about that right now. Let's focus on part throttle MAF tuning first, then move on to VVE tuning with a wideband.

Okay - so should i change the setting on the long term back to 300 ?
also attaching a current log file after turning on lt's & seeing more kr.

[K Rob]

Okay - so should i change the setting on the long term back to 300 ?
also attaching a current log file after turning on lt's & seeing more kr.

how do i disable dynamic airflow & set to maf only /
what tabs ?

[village_idiot]

Leave LTFT enabled

In the tune I sent you, it?s MAF only. When dynamic is enabled the RPMs under the dynamic fuel tab will be at 4000 & 3900 stock. This means up to 4000 it will use a combination of MAF and VVE (dynamic), and above 4000 it will reference MAF only. The file I sent you is set at 100 & 50, forcing it to read MAF only above 100rpm. You have to tune MAF and VVE separately, so we do MAF first, then VVE afterwards....then re-enable dynamic

[K Rob]

Leave LTFT enabled

In the tune I sent you, it?s MAF only. When dynamic is enabled the RPMs under the dynamic fuel tab will be at 4000 & 3900 stock. This means up to 4000 it will use a combination of MAF and VVE (dynamic), and above 4000 it will reference MAF only. The file I sent you is set at 100 & 50, forcing it to read MAF only above 100rpm. You have to tune MAF and VVE separately, so we do MAF first, then VVE afterwards....then re-enable dynamic

okay so I need to do another log after changing these settings ?

[K Rob]

new log - just idle - no rpm being registered as well as others

[K Rob]

got my pid's to work - another log & car died when I put in reverse to back out of driveway

[K Rob]

GM - if anyone is able to walk me through tuning my MAF over the phone it would probably be much quicker & easier. Just send me a private message. TIA

[village_idiot]

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