E67 Actual A/R Ratio?

[[email protected]]

Noob to HP Tuners so go easy....

I have an E67 crate swap ECU (OS 12638778) on an LS3 running an Edelbrock supercharger. Trying to tidy up fueling to bring the ST and LT fuel trims into line.

FIRST--I can't find a channel that reads actual A/F ratio from the widebands. There is Air-Fuel Ratio Commanded, Equivalence Ratio Commanded and O2 Voltages--but nothing for actual A/F or Equivalence ratio (even Lambda). I've repolled and repolled to look for something. What am I missing?

SECOND--I can't find a basic VE table, fueling table (pulsewidth) or even A/F table. I'm used to working with these in a FAST or Holley SD systems, but its not present here. Am I missing something? What defines the target A/F (equivalence, Lambda...) ratio that the system is trying to hit? Is it even doing that?

THIRD--is there a book, website, YouTube channel or online course that I can dig into to learn how to tune with HPT on this E67 and its OS?


TIA for any assistance.




THANKS


G

[5FDP]

1. That is because GM does not use wideband sensors. They use narrowband sensors so you will never know the real time air fuel ratio or lambda unless you install a wideband sensor into the exhaust and wired into HP Tuners.

You can monitor what the computer is commanding but not what you are getting. Thus the need for the separate wideband sensor.


2. There isn't one. This generation of computer use a virtual VE table. Those are found under the edit tab. You have the MAF airflow vs freq that control fueling and the VVE tables under the edit tab.

3. Yes there are books and courses. There are plenty of youtube video's as well for some of this stuff. Even the VCM scanner section has a few write up's in the sticky pages for setting up graphs for logging.


Standalone systems have it easy for lots of stuff. Tuning a stock GM computer is an art and takes a lot longer to learn all the in's and outs.

[kevin87turbot]

Noob to HP Tuners so go easy....

I have an E67 crate swap ECU (OS 12638778) on an LS3 running an Edelbrock supercharger. Trying to tidy up fueling to bring the ST and LT fuel trims into line.
Did you have anyone put a base tune for the supercharged application? If you'll post the tune file we can help a lot more.

FIRST--I can't find a channel that reads actual A/F ratio from the widebands. There is Air-Fuel Ratio Commanded, Equivalence Ratio Commanded and O2 Voltages--but nothing for actual A/F or Equivalence ratio (even Lambda). I've repolled and repolled to look for something. What am I missing?
What wideband sensors are you running? The OE sensors for the E67 applications are narrowbands.

SECOND--I can't find a basic VE table, fueling table (pulsewidth) or even A/F table. I'm used to working with these in a FAST or Holley SD systems, but its not present here. Am I missing something? What defines the target A/F (equivalence, Lambda...) ratio that the system is trying to hit? Is it even doing that?

The OE calibration in the E67 PCM's use a combination of Speed Density and MAF calibrations. They typically use both SD and MAF at lower rpm's and primarily use the MAF above 4000 rpm. Many tuners will just use one or the other instead of both.

Yours will have 4 Virtual VE tables found under the Edit tab. I typically modify all four of them, but you don't have to mod the DOD based tables if you aren't using DOD.

THIRD--is there a book, website, YouTube channel or online course that I can dig into to learn how to tune with HPT on this E67 and its OS?
There are several options for learning to tune the OE PCM's. The Tuning School is a popular one. You might look at EFI University as well. Ben Strader is a wealth of knowledge.
For YouTube videos, look for James Short from Shortuning, and Goatrope Garage and The Tuning School.


TIA for any assistance.




THANKS


G

[[email protected]]

1. That is because GM does not use wideband sensors. They use narrowband sensors so you will never know the real time air fuel ratio or lambda unless you install a wideband sensor into the exhaust and wired into HP Tuners.

You can monitor what the computer is commanding but not what you are getting. Thus the need for the separate wideband sensor.


2. There isn't one. This generation of computer use a virtual VE table. Those are found under the edit tab. You have the MAF airflow vs freq that control fueling and the VVE tables under the edit tab.

3. Yes there are books and courses. There are plenty of youtube video's as well for some of this stuff. Even the VCM scanner section has a few write up's in the sticky pages for setting up graphs for logging.


Standalone systems have it easy for lots of stuff. Tuning a stock GM computer is an art and takes a lot longer to learn all the in's and outs.

Well, I've learned something--no wideband sensors. Time to go get an external unit. Thanks for your answers. I've spent quite a bit of time reading the forums and looking at YouTube and most of what is there is for older ECUs/OS that show VE tables and such. Haven't found much detail on the E67.

[[email protected]]

thanks, kevin87turbot! Good info. Yes, I had Chuck at B3R near Cleveland (my area) modify the tune for the supercharger. it generally does fine, but I see ST and LT trims in areas that could be improved. I'll grab my other laptop and post the tune and scan file--that just gets posted in this thread, right?

And thanks for the references for education. Hoping that someone has something focused on the E67 as it seems this is quite a bit different than the older versions. I've watched a few videos from Shortuning, but nothing so far specific to E67.

[5FDP]

Pretty much anything you find on the E38 and E67 will be the same. The VVE stuff would be the same for both computers.