95 lt1 injector offset questions

[spfautsch]

As best I can recall, yes - that is / has been the prevailing wisdom on this topic. For the $EE mask (again, as best I can recall) it's believed that this table contains signed integers that are all negative.

Just for a sanity check though, can you verify the address of the table you're talking about pls? I've been swamped at work for the last couple weeks and simply haven't had time to delve into tuning stuff.

[yoheer]

0x129F5

[spfautsch]

That's the one. Yes, zero it if using modern injectors.

[kur4o]

That table compensate for non linear behaviour of fuel flow on low pulse widths[upto 4ms with patch]. Too bad lt1 code don`t allow negative corrections of it, since some injectors needs negative offset.

If you have data use it or extrapolate some. Otherwise you will have non-consistent fueling with less than 2-4ms pulse width, wrecking havoc on your tuning efforts.

[yoheer]

How to fill this table using this data?

https://documents.holley.com/accel_i...ons_150136.pdf

[spfautsch]

Search for "injector flow rate knee" - it's critical to understanding what this is correcting. At lower pulsewidths the injector has a different flow rate. Above this inflection point (say for example around 2ms) the injector's flow rate is more or less linear.

To vastly oversimplify, the injectors GM used in these early systems had a lower flow rate below the inflection point, thus requiring an adder to make fuel metering accurate.

Conversely, most modern injectors have a higher flow rate below the knee, requiring subtraction. The $EE mask is incapable of this, which is why the only thing that can be done to this table with modern type 3 injectors is to zero it.

[yoheer]

I roughly understand
I believe mine are type 2 injectors
Could you please explain me, how to manage this table, using data from the table below? (If there is enough data and if it's possible to do it.) As an example.

[spfautsch]

I wish I was of more help, but that's unlike any injector characterization I'm familiar with. Also, possibly more important than low slope compensation (the purpose of the 0x129F5 table) is a lack of an offset vs voltage table.

[Fast355]

Search for "injector flow rate knee" - it's critical to understanding what this is correcting. At lower pulsewidths the injector has a different flow rate. Above this inflection point (say for example around 2ms) the injector's flow rate is more or less linear.

To vastly oversimplify, the injectors GM used in these early systems had a lower flow rate below the inflection point, thus requiring an adder to make fuel metering accurate.

Conversely, most modern injectors have a higher flow rate below the knee, requiring subtraction. The $EE mask is incapable of this, which is why the only thing that can be done to this table with modern type 3 injectors is to zero it.

Has to be a way around that. Like add a consistent value to it and subtract it somewhere else. It has been a while since I looked at $EE to see whats there.

[steveo]

if its a flow rate modifier cant you just scale the injector constant to bias the table?