injector flow rate

[goodwrenchdave]

6.0 G8 -e38- I'm stumped!
Ive been trying to dial in new injectors (80lbh) and they keep coming out rich -especially at idle. (11.8 on wideband; -22+LTFT on 02). Since these are "budget injectors" with less than ideal reputation, I figured the data i received was more "generic" than specific flow data for these injectors.
....Trying all options, decided to "guestimate" IFR by taking stock flow and multiplying by 1.05 till i reach 80lb/h (much like when decapping stock injectors).

Long story short - this is when noticed that stock oem IFR data (stock oem injectors) for the G8 already seems screwed up- anybody noticed that its not programed as a linear table? this is the stock table- yet same injector in a camaro is different data
____

41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 41.1752027762284 42.2583528163183 43.3182509771935 44.3452089758476 45.3527904084894 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214 46.3448705883214

whats up with that?
I had to double stoich and half flow,itv ... but else seems to be adding fuel

[nicks1031]

What kind of fuel system is being used? Is it Baro Referenced, or MAP referenced?
Was offset data provided? Short Pulse adders?

[goodwrenchdave]

This is a returnless system 58psi. under offset select it says vacuum (but that is what it was oem calibration...so still the same)
This is all at idle-and slightly above.... i'm scared to go over 2000 rpm because there is now a cam and supercharger installed. need to get fuel set up before continuing tuning...... dont need things blowin apart!

and Yup, got flow rates, adders , offsets ....with injectors but I had i feeling they where "copied" from some other brand. I tried the injectors on the stock unmodified car setup and they ran rich then too.- more on that later (i now realize something was off)
The closest I got to proper mixture running was inputting data from another brand (the FIC 850 injector data seems to run the best but still rich).

I just learnt tonight about the gen4 tendency to run rich after hot reflash (inj tip temp offset). And i think this has been throwing me an extra loop/confusion..... I mean every little change i reflash and it seems to get worse the hotter the car got ... till i gave up in desperation.
I now zeroed that table- hopefully gonna be able to get somewhere......

If not ....guess I'll start looking for some id850 (or even stock lsa injectors- at least then the car will run!

[07GTS]

do not zero the inj tip temp offset table u go from a rich after flash to lean after flash, best to tune it in properly for repeatable results or at least beg very close

[nicks1031]

This is a returnless system 58psi. under offset select it says vacuum (but that is what it was oem calibration...so still the same)
This is all at idle-and slightly above.... i'm scared to go over 2000 rpm because there is now a cam and supercharger installed. need to get fuel set up before continuing tuning...... dont need things blowin apart!

and Yup, got flow rates, adders , offsets ....with injectors but I had i feeling they where "copied" from some other brand. I tried the injectors on the stock unmodified car setup and they ran rich then too.- more on that later (i now realize something was off)
The closest I got to proper mixture running was inputting data from another brand (the FIC 850 injector data seems to run the best but still rich).

I just learnt tonight about the gen4 tendency to run rich after hot reflash (inj tip temp offset). And i think this has been throwing me an extra loop/confusion..... I mean every little change i reflash and it seems to get worse the hotter the car got ... till i gave up in desperation.
I now zeroed that table- hopefully gonna be able to get somewhere......

If not ....guess I'll start looking for some id850 (or even stock lsa injectors- at least then the car will run!

Post a tune file.

If the fuel system is 58 psi and manifold referenced, and judging from a stock G8 file , it is - Then you would also need to apply this constant fuel pressure logic to the injector data. Not sure if you've done this since there's no file posted here.

[goodwrenchdave]

Id like someone to explain this IFR table to me because i guess i dont understand it- is it strictly about rail pressure ? (then knowing most GM are fixed at 58psi mechanically regulated at pump all the cells other than the 58 cell are a waste
And if it references Bernoulli principle then any cell over 73 psi is useless (58 pump pressure + 15 (maximum vacuum)) and any cell under 58- normally aspirated or 40 with 18 pounds of boost is also useless. I'm populating them with the given data anyways, but dont know why these extra cells are there.

Ill post the file tomorrow - its on another computer.

[nicks1031]

Id like someone to explain this IFR table to me because i guess i dont understand it- is it strictly about rail pressure ? (then knowing most GM are fixed at 58psi mechanically regulated at pump all the cells other than the 58 cell are a waste
And if it references Bernoulli principle then any cell over 73 psi is useless (58 pump pressure + 15 (maximum vacuum)) and any cell under 58- normally aspirated or 40 with 18 pounds of boost is also useless. I'm populating them with the given data anyways, but dont know why these extra cells are there.

Ill post the file tomorrow - its on another computer.

As long as the data is from a reputable injector company, I would just plug it in and go. There are a lot of tables in OEM computers that will never see full range of use. Best to not get too caught up in those things.