Injector boundary values and EOIT

[maudyZ28]

hi everyone, I had to get into this recently (still waiting for the car to run the new tunes) because the mild/medium cam (218/237 ish - proprietary spec so we don't know the size) has way more bucking at low throttle. I figured the exhaust is open when we are spraying so the fueling is off - I can richen up a smidge in open loop and it cleans right up (more fuel in the cylinder where I want it), but then I have to watch out for goosing the cats and poor economy.

Basically I see all the injector timing values in EFI live - but we don't have a boundary table. I saw an old post (2016) about a cax file for this, but surely it could have been added (I think not now as the E38 is old hat). It that cax still around?

My other concern was the values in EFIlive are a factor 2 (exactly) more than all the vcm HP tuner stuff (I don't have it but there is info online). Any ideas about this, i'm literally just doubling my changes as calculated.

My final point, although i've run the calculations (but don't have a camaro tune to hand) is that everyone says the boundary values are 520 (deg), but actually the Corvette tunes (for which I have form 4 independent cars) actually use a changing boundary condition for EOIT calculation (510 at low rpm <1500 ish, and then around 470 to 480 ish for higher RPM). I don't know if the other values change for the camaro, but from material I have access to, it seems not. So basically the camaro's (all things being the same) would have a way later injection EOIT and thus for a given spray time, a later SOIT. The vette tunes are like 50 deg advanced.... what gives?

[maudyZ28]

In addition I did run the calculation (I don't have the notes right now but it is sufficient for some comparisons) and then anyone can chime in with other ideas:

infor from elsewhere on standardized valve events for LS3 circa 0.004 or 0.006" lift (advertised duration) - where 0 is TDC starting the power stroke (then exhaust, intake, compression)
IVO 371 IVC 585
EVO 135 EVC 347

at Idle, say 600 rpm here: this does 3.6deg in 1ms

Boundary for Camaro tune would be 520, Vette is 507.
Run the numbers and EOIT are 380 deg and 367deg respectively (only normal ECT and multi-spray angles have populated tables). We could take off ~5-10 deg to work out start of Injection assuming a 1-2 ms pulse width. (just for ball park numbers)

Although these are more of less the same, the camaro more or less sprays with a closed exhaust valve (347) but more or less as the intake is opening.
The vette sprays is a bit more advanced, to EXHAUST is 'just' closed, but more importantly the INTAKE is also closed (371deg) - my theory to hit to closed value briefly before to allow better 'atomization' (wrong word it was explained elsewhere, but I forget)

When we move to higher RPM, the camaro tune only shift slightly advance for the RPM table getting populated, so more or less still around exhaust closing, and just before intake opening.
The boundary for the vette shifts to ~470-480, so it always sprays way way before (50 deg) than the camaro, and when the exhaust is full open, but the intake is 100% still closed. Why, better atomization, or the way the intake works with the runners - this I don't get.

Either way now adding a cam to the LS3 vette i'm tuning plays havoc at low RPM. And the suggested fix to retart timing by 10-20 deg I cannot see working as the boundary is so different vs the camaro, I can never get this sensibly when the exhaust is closed - or I take 50-60 deg out.

[Highlander]

only the ECT tables are followed.

[ddnspider]

Could one of you give me a hand on my EOIT adjustments? I've tried searching here and the other tuning platform and everyone seems to be doing things differently and the HPT tables don't convert from what I can see. Is there a clean way to calculate this or a ballpark of how many degrees I can add knowing I have a larger cam in an LS7?

[Cringer]

First post here for me...

I spent a good chunk of the summer with an oscilloscope figuring out injector timing. I found some interesting results as well and combined with input from someone who is adept at reading the hex, it turns out that EOIT is far more complicated than we all thought (https://forum.hptuners.com/showthread.php?111145-Make-Up-Mode-you-wiley-devil-you&p=800812&viewfull=1#post800812). I did summarize my data, testing, and findings here: https://youtu.be/FmdJOOUUqQg

I did create a new and corrected EOIT calculator program too. Demo video (and download link in video description): https://youtu.be/viLlBZVbeag
Note that all the previous spreadsheet calculators are incorrect and missing other required elements.
Additionally, this is geared for my tuning background with product "H". However, I am looking to explore the EFILive tools though, which brings me here and why I randomly saw this post.

I am also getting comfortable with generating XDF files...so I assume CAX file are same/similar that I should be able to add them for the Normal Boundary table. Is there a repo for CAX files that is publicly available?

Here is how the EOIT is calculated on a Gen4 controller:
Normal Pulse:
= [Boundary Angle] + [Fuel Pressure Boundary Offset] + [Intake Cam Boundary Offset]
[Adders] = (2*[Normal ECT])
[EOIT] = [Boundary] - [Adders]

Make Up Pulse (used for transient fueling if needed after the normal pulse occurs):
[Boundary Make Up] = [Boundary] + [Fuel Pressure Boundary Offset] + [Intake Cam Boundary Offset]
[Make Up Adders] = (2*[Make Up ECT])
[EOIT] = [Boundary Make Up] - [Make Up Adders]

[SOIT] = [EOIT] - [IPW converted to degrees]


What you need to keep in mind:
[LIST]
[B]The Normal and Make Up ECT values are doubled for the EOIT calculation.
All the ECM's I have seen have the Fuel Pressure Boundary modifier set to zero. Looks like a feature that is available, but never used.
All the ECM's from true LS motors (no variable cam) have the intake cam boundary modifier set to 0

[Cringer]

First post here for me...

I spent a good chunk of the summer with an oscilloscope figuring out injector timing. I found some interesting results as well and combined with input from someone who is adept at reading the hex, it turns out that EOIT is far more complicated than we all thought. I did summarize my data, testing, and findings here: https://youtu.be/FmdJOOUUqQg

I did create a new and corrected EOIT calculator program too. Demo video (and download link in video description): https://youtu.be/viLlBZVbeag
Note that all the previous spreadsheet calculators are incorrect and missing other required elements.
Additionally, this is geared for my tuning background with product "H". However, I am looking to explore the EFILive tools though, which brings me here and why I randomly saw this post.

I am also getting comfortable with generating XDF files...so I assume CAX file are same/similar that I should be able to add them for the Normal Boundary table. Is there a repo for CAX files that is publicly available?

Here is how the EOIT is calculated on a Gen4 controller:
Normal Pulse:
= [Boundary Angle] + [Fuel Pressure Boundary Offset] + [Intake Cam Boundary Offset]
[Adders] = (2*[Normal ECT])
[EOIT] = [Boundary] - [Adders]

Make Up Pulse (used for transient fueling if needed after the normal pulse occurs):
[Boundary Make Up] = [Boundary] + [Fuel Pressure Boundary Offset] + [Intake Cam Boundary Offset]
[Make Up Adders] = (2*[Make Up ECT])
[EOIT] = [Boundary Make Up] - [Make Up Adders]

[SOIT] = [EOIT] - [IPW converted to degrees]


What you need to keep in mind:
[LIST]
[B]The Normal and Make Up ECT values are doubled for the EOIT calculation.
All the ECM's I have seen have the Fuel Pressure Boundary modifier set to zero. Looks like a feature that is available, but never used.
All the ECM's from true LS motors (no variable cam) have the intake cam boundary modifier set to 0

[Cringer]

First post here for me...

I spent a good chunk of the summer with an oscilloscope figuring out injector timing. I found some interesting results as well and combined with input from someone who is adept at reading the hex, it turns out that . I did summarize my data, testing, and findings on my youtue channel (looks like I am being prevented from posting links?).

I did create a new and corrected EOIT calculator program too. Demo video (and download link in video description):
(again looks like I cannot post links)
Note that all the previous spreadsheet calculators are incorrect and missing other required elements.
Additionally, this is geared for my tuning background with product "H". However, I am looking to explore the EFILive tools though, which brings me here and why I randomly saw this post.

I am also getting comfortable with generating XDF files...so I assume CAX file are same/similar that I should be able to add them for the Normal Boundary table. Is there a repo for CAX files that is publicly available?

Here is how the EOIT is calculated on a Gen4 controller:
Normal Pulse:
[Boundary] = [Boundary Angle] + [Fuel Pressure Boundary Offset] + [Intake Cam Boundary Offset]
[Adders] = (2*[Normal ECT])
[EOIT] = [Boundary] - [Adders]

Make Up Pulse (used for transient fueling if needed after the normal pulse occurs):
[Boundary Make Up] = [Boundary] + [Fuel Pressure Boundary Offset] + [Intake Cam Boundary Offset]
[Make Up Adders] = (2*[Make Up ECT])
[EOIT] = [Boundary Make Up] - [Make Up Adders]

[SOIT] = [EOIT] - [IPW converted to degrees]

[Cringer]

Continued...

What you need to keep in mind:
[LIST]
The Normal and Make Up ECT values are doubled for the EOIT calculation.
All the ECM's I have seen have the Fuel Pressure Boundary modifier set to zero. Looks like a feature that is available, but never used.
All the ECM's from true LS motors (no variable cam) have the intake cam boundary modifier set to 0

[ddnspider]

We dont have a cax available for this to get the tables like HPT does. But I followed Greg Banish video on how to dial in EOIT and it made a difference in the exhaust smell for sure. He goes through it using EFI Live AND HPT in the video so its easy to follow.

[Tre-Cool]

Cringer it's likely because your a new member that is preventing your links from showing up. Will be a forum limit for spam bots until you reach a certain amount of posts.