Adjusting injector slope and effects on WOT fuelling?

[BoostFrenzy]

It seems to me if you're adjusting the injector slope (telling the ecu the size of the injectors is different!) that you're in effect sliding the WOT fuelling that much more rich/lean from it's intended target

in my experience any time fuel trims were off you'd want to scale the maf / intake calibration and if it required adjusting the injector scaling, you'd need to tune WOT fuelling again.

does anyone agree with me here? i think i'm going to run a 0% injector slope so i can achieve diablosport's intended afr's

[sohfast94]

That's what I would do. The injector slope affects "All Fueling" not just WOT.

[BoostFrenzy]

That's what I would do. The injector slope affects "All Fueling" not just WOT.

why is everyone changing their slopes then? so what if you get close to 0% LTFT if it's in turn affected your WOT fuelling, or if they pull say 5% for LTFT do they also pull 5% from the PE fuelling?

[06MonteSS]

yes, if you read the user manual, it says that if you go -5% on slope, that you should also subtract that same amount from your PE fueling, so you would also go -5% in both rpm ranges for PE, to compensate for the added fuel you just created by going negative on slope.

[BoostFrenzy]

ok, wanted to be clear on that, i was making slope changes without PE changes and monte regarding our trim discussion, weather changed drastically from when i had sent you those WOT logs and my trims WERE 8% positive when it was still hot friday, however now they're 3 and 4% negative with a -8% setting as it's cooled off considerably and much less humidity, i think i'm going to go with -5% as a happy medium

[CANUCKPREDATOR]

Best option is to tune on your hottest, most humid day. That way when things cool off and humidity falls you won't hurt your motor. If you want to, you could adjust every day to compensate for the weather, but that's just a PITA.

[BoostFrenzy]

well am i correct in saying if i go -5% on the slope to also go -5% in both PE fuel ranges as well?

[swillia2]

I thought I read to just adjust just the slope to get proper spray and then at WOT it would be correct aswell? Newbie, so just asking?

[CANUCKPREDATOR]

This is were adjustments seem wierd. LTFT adjustment to the negative makes injectors shoot more fuel. PE adjustment to the negative are making the injectors shoot less.

Some vehicles it can be correct, that's why you need to WOT log/monitor after you get your LTFTs set.

[2001z06]

I thought I read to just adjust just the slope to get proper spray and then at WOT it would be correct aswell? Newbie, so just asking?

newbie...but I read the same thing or least I thought I read that.

[CANUCKPREDATOR]

I thought I read to just adjust just the slope to get proper spray and then at WOT it would be correct aswell? Newbie, so just asking?

newbie...but I read the same thing or least I thought I read that.

Sorry forgot to hit the quote button. If can for some vehicles, but not every vehicle is the same. You should log/monitor for TSKR at WOT to see if you need any further adjustments.

[shadow]

I thought I read to just adjust just the slope to get proper spray and then at WOT it would be correct aswell? Newbie, so just asking?

Thats what i thought i read also.

[shadow]

sorry just read above post

[concoursd]

your WOT fuel settings are commanded values. Theoretically, the commanded values should be optimized by DiabloSport's dyno tuning for stock/mostly stock applications. Therefore, if you adjust the injector slope (which is a global fuel setting) to dial-in your part throttle fuel settings, then you should also compensate for that change in the WOT settings (ie. if you reduce the injector slope to richen up the fuel mixture at part throttle, then you should lean out or reduce your WOT settings). Otherwise, then it is possible that your WOT settings will be too rich.

As mentioned before you will want to do some WOT datalog runs to check and see if you should adjust them and by how much.

[06MonteSS]

I thought I read to just adjust just the slope to get proper spray and then at WOT it would be correct aswell? Newbie, so just asking?

Thats what i thought i read also.

all you guys who thought you read that... you probably did, cuz I believe I said it on my tutorial...

however, if you notice at the top of that, there is that li'l disclaimer there about how the info is for MY car... every vehicle is different...

usually the trucks are fine too, gto's, impala's, gxp's, etc etc...

HOWEVER, the Vettes come PIG RICH from the factory, so yes, you may need to do some adjusting to your PE settings.... no big deal...

the diablo tune leans it out quite a bit from factory settings, but, if you have to go negative on your slope, you're just going to be adding that fuel back in at WOT, making it richer again... so, you may need to adjust your PE settings as well.

get the correct logs done and you can see where your numbers are at, and make adjustments accordingly...