IFR question

[picnic_george]

This el camino ls2 swap(0411 pcm) has stock ls2 injectors 12569113. I copied the IFR from the stock 05 GTO calibration but I wonder if that is correct. This is running a return style fuel system. With an LS6 base map in the car it goes super lean when you stab the throttle at low rpms. The car will stumble. Before I completely redo the VE tables and realize how messed up it is. I've added about 30% and it's still lean. I don't know why it would do this and I have yet to see this happen on anything I've done. Fuel pressure is constant 58psi, no vacuum leaks, going to check to see if the injectors are sticking.

What should the IFR be for this type of setup. Not at my laptop right now so I can't post what my settings are, but they are stock ls2 gto.

Thanks
Kris

[joecar]

Are those injectors the same as the 2005 GTO that you copied the IFR from...?

Was your VE already scaled...? If so you would need to scale the copied IFR down by the same scaling factor.

If you run a manifold-referenced FPR then the IFR should be flat (base pressure is measured with reference hose temporarily disconnected);

the GTO's IFR would be sloped.

[picnic_george]

Are those injectors the same as the 2005 GTO that you copied the IFR from...?I'll double check that. But I thought they all used the same injector. The motor was an 05 GTO M6, same as the car I got the IFR table from.


Was your VE already scaled...? If so you would need to scale the copied IFR down by the same scaling factor.How do I scale the VE? I just used the base VE from a z06 and changed the displacment to 6.0L as my base.


If you run a manifold-referenced FPR then the IFR should be flat (base pressure is measured with reference hose temporarily disconnected);

the GTO's IFR would be sloped.Non-referenced so I assumed it should be sloped and the same as stock. It's actully using the corvette filter for the return so it's not a true return style like I may have made it seem.

[joecar]

When you view your VE using units g*K/kPa, does it look the same as the LS6 VE (using units g*K/kPa) that you copied from...?

Did you copy the other injector tables...?

Was the VE already corrected...?

Doesn't the LS2 have different cam specs than the LS6...?

[picnic_george]

No the VE is different because I adjusted the engine size.

What other injector tables should I be copying? I just adjusted the IFR table.

I haven't corrected the VE yet(assume you're talking through tuning)

Yes the cam is slightly different but not enough to make the car go so lean it pops when you hot the throttle off idle. Besides I've added a ton of fuel in those cells to see if it corrects the problem, which it got better but at the same time I know it was too much. Should be close from the get go seeing as how the two engines are fairly similar.

IFR is the only thing I can think of since there doesn't seem to be anything mechanically wrong with the car. Here is what my IFR looks like. Maybe somoene can correct me or help with another setting I'm missing.

Injector Flow Rate (Grams/Second)
Manifold Vacuum kPa {link: GM.MANVAC} Value
0 4.171875
5 4.195313
10 4.218750
15 4.242188
20 4.273438
25 4.296875
30 4.320313
35 4.343750
40 4.375000
45 4.398438
50 4.421875
55 4.445313
60 4.468750
65 4.492188
70 4.515625
75 4.539063
80 4.562500

Thank you as always Joe appreciate the help

[picnic_george]

Here is the tune, before any tuning changes have been made. Might help.

Thanks

[joecar]

No the VE is different because I adjusted the engine size.
...When you view VE as g*K/kPa, the displacement has no effect on the VE

( displacement effects the view of VE when it is viewed in % units, but otherwise has no effect on VE )

[joecar]

Hmmm...

you might try this:

setting units to g*K/kPa and comparing VE tables...

and then scaling your VE for engine displacement (i.e. multiply the VE by new_volume/old_volume) and see how it runs.

[joecar]

I have seen no running changes when I edited only the cylinder volume parameter.

[picnic_george]

Hmmm...

you might try this:

setting units to g*K/kPa and comparing VE tables...

and then scaling your VE for engine displacement (i.e. multiply the VE by new_volume/old_volume) and see how it runs.I assume you mean multiply the whole VE table in g*k/kPa by 1.05% seeing as how that is the difference in engine size. It would seem it is off by more than 5%, but no biggie. Why doesn't that number automaticalyl change when you add/subtract from the VE table listed as %? Interesting though, I will go ahead and do that so I know it's correct.

[joecar]

IDK why B0104 does not make a VE change.

[picnic_george]

It changes the fueling in the same fashion, just doesn't change the VE %?

[joecar]

Try this experiment:
- set VE units to g*K/kPa,
- restart the tunetool;
- change B0104,
- save as new file,
- exit and restart tunetool,
- compare original file and new file, note the difference;
- now set the VE units back to %,
- exit and restart tunetool,
- compare original file and new file, note the difference.

[picnic_george]

That's exactly what I was going to do. I'll be back at it in a couple hours and I'll report if it makes things better.

After research looks like the IFR is correct. If it's not it's damn close. All info on those injectors say 34lbs at 58psi when I plug those #s into the xls spreadsheet it comes with a difference of less than .1 all the way accross. I'm sure the 34lb # I keep seeing is just close not perfect.

I'll take any other suggestions from anyone else if they think I'm missing something.

Thanks again
Kris

[picnic_george]

Just got to my laptop, I already made those changes previously. When I changed IFR or cylinder volume whichever it was, the VE table did change. I couldn't figure out how to change to g*K/kPa but looking at the way I have it setup it's already listed that way but I thought it was in percentage. Maybe, maybe not. But either way it has been changed about 5% comparing to the stock Z06 VE tables. Unless I'm doing that wrong, how do I change it, but it looks fine to me lol


NEVERMIND FOUND IT... THANKS