WOT fuel

[05silvycrew]

predator u7193, 05 silverado, 5.3 iron block. LTFTs already dialed in

on the adjustable perameters explained page, under injector slope, it says:

"Once you get the average long term fuel trim value:
For a positive value you subtract that value in percent in the predator injector slope. It is also recommended to lean both fuel tables by the same percentage."

So, if I'm following this right, we're adjusting the LTFTs to be richer (by subtracting from the injector slope). Then, making both the WOT fuel tables leaner by the same percentage we made to the injector slope. Is this correct?

can someone explain why we make one richer and the other leaner. does that need to be done for balance? sorry, but I like understanding everything I'm doing, before I do it.

[spikeyjohnso]

Where does one find the answer to this post? U9000 coverted to U7198

[mikel]

That info is based on the assumption that before your inj. slope change, the WOT A/F was correct, so after adding fuel with the inj slope change, you would need to remove what you added at WOT to get back to where you were prior to the change.

[05silvycrew]

That info is based on the assumption that before your inj. slope change, the WOT A/F was correct, so after adding fuel with the inj slope change, you would need to remove what you added at WOT to get back to where you were prior to the change.

without the ability to get the exact A/F ratio at WOT, you would be making changes blindly in the PE mode. I think you need a wideband o2 to see A/F ratios at WOT, correct?

-dialing in LTFTs affects the WOT fueling
-can't adjust WOT fueling without an accurate A/F ratio
-can't get an A/F ratio without a wideband
-can't go after spark/timing without having WOT fueling dialed in

anybody see an answer, short of getting a dyno tune, or buying a wideband myself?

[06MonteSS]

yeah, for yours, you would need to get a wideband hooked up - either buying one with a gauge yourself, or goin' for a few pulls on a dyno somewhere...