E38 injector flow rate v voltage doesnt work?

[8aHemi]

I've found that when the alternator is charging at 15v, I'm roughly 10% richer than when its charging at 14v... No big deal ill mess with the flow rate vs voltage table. Ive messed with it enough to come to the conclusion that it doesnt do anything at all that I can tell. Am I missing something, or is this a common occurance?

My current plan is to multiply the values supplied by injector dynamics for flow rate vs voltage, to the injector offset vs pressure delta vs voltage table, on the voltage axis. For example at 14v ID suggests a .918 multiplier, and at 15v it suggests a .879 multiplier. If i take these values and multiply them across the delta vs voltage table I should end up at the same value in the end correct? Is this a incorrect way of thinking? Couldnt really find much on this stuff.

[blindsquirrel]

I think you are on the wrong track altogether, which can sometimes explain why you can't find info on others having done it before.

[Alvin]

I think the error might be in some other model.. airflow..etc

I think it would be smart to check fuel pressure while the alternator is at 15v vs 13v. One volt could be +20% in fuel pump flow. If you are truly getting more fuel because the pressure is higher.. the fix wouldn't be changing a injector characteristic.. It would be keeping the pressure better regulated. The error could be from a vacuum referenced regulator too...

That's a topic I'm ready to have.. how far off these 1:1 fuel pressure regulators are.. and how they aren't even consistently off.

[8aHemi]

I think the error might be in some other model.. airflow..etc

I think it would be smart to check fuel pressure while the alternator is at 15v vs 13v. One volt could be +20% in fuel pump flow. If you are truly getting more fuel because the pressure is higher.. the fix wouldn't be changing a injector characteristic.. It would be keeping the pressure better regulated. The error could be from a vacuum referenced regulator too...

That's a topic I'm ready to have.. how far off these 1:1 fuel pressure regulators are.. and how they aren't even consistently off.

Yeah I wish I could command charging voltage, its pretty random when it decides it wants to charge at 15v or 14v.. Ill check fuel pressure out. I noticed that the differance between the two voltage multipliers, is around 10%, which is also about how much my trims vary with voltage. I made the changes to the delta vs voltage table. I havent noticed anything abnormal, but I dont have enough data to say if it corrected the issue or not. If fuel pressure is steady, is this a viable solution or will something get jacked up along the way? Stock tune file for a 09 g8 GT has the voltage table zeroed out, and I honestly dont think it does anything at all.

[07GTS]

they arnt voltage multipliers, they are offsets, if u have to inject a 1ms PW without the offsets u may not get any fuel at all, the offset and short pulse are used/added to the PW so when a 1ms PW is asked for it can deliver it

[Alvin]

Some OS's do have a voltage multiplier.. not offset.

it's not how I would go about this.. I'd verify the things I said before.

[07GTS]

ooh just the volts multi, ive herd it works in some but not in others, i found it dosnt work in mine, but a change of 1v shouldnt trigger a 10% shift in fueling otherwise id have a 30% shift when my alternator is in eco mode on hwy

[8aHemi]

I?m still playing with this but so far I?ve got trims consistent with voltage except on decel it will go rich with dfco off, it also seemed to amplify my bank to bank fueling which lands at around 7% off as of now.