Tuning a 93 3.4 Firebird

[tkoforpresident]

these are the adjustments that Fuel Trim is telling me i need to make. Does it look like i did it right? (i think i did...)

still looks like its WAY off VE doesn't it? Did our previous changes do ANYTHING? WTF =/

Edit: there are a couple cells that are only calling for ~.992 change so i guess thats progress right? lol

[tkoforpresident]

here it is.

edit: BTW, are we sure my BPC is correct? (193) that's for 19lb injectors @50psi. That was using IsaacHayes posted formula and i was pretty sure i got my #'s correct, just want to double check. Someone questioned whether my BPC was too high so I just want to ask you guys.

In fact is it really a formula that we use to determine BPC? I've been told that you just decrease the BPC til it leans out... i'm being pulled in all directions lol

Double Edit: If i may take such liberties as to double edit, i found this quote by superdave "the chip i did for a 3400 swapped Z24 has the BPC at 136, that's 22.5lb/hr (stock 3400) with the 55PSI FPR."

Those are bigger injectors than mine AND higher psi.... yet the BPC is WAAY smaller.

I'm not trying to throw doubt on anything here but you can see why i am quite confused.

[IsaacHayes]

The bigger injectors/more fuel, the smaller the BPC will be.

[robertisaar]

The bigger injectors/more fuel, the smaller the BPC will be.

X2, and max: i would just go by what it says(full value) and then see how much closer it gets.

[tkoforpresident]

ah my bad. I was wrong bout the bpc then. I'll do the full values this time and see how it goes.

Question: should I be only looking at the " BLM Cell 0" column in my datalogs since i'm just tuning idle right now or just group it all together (BLM Cell 0 and 1) and plop the data into fuel trim?

[robertisaar]

in A1 there are 3 BLM Cells, all used for different things. disregard it, it's nothing too important to keep watch on.

[tkoforpresident]

ok fair enough. I'm gonna go make my VE changes now (did you ever look at my out table data robert?) including all the big .464 etc. changes

[tkoforpresident]

Robert, what changes did you make to my .bin? because now my idle VE table is different than my Main VE table even though i made them the same values (at least in the rpms that i could) and now i don't know if the adjustments i just hammered out in fuel trim are going to be good for the current tables since they are prior to your .bin changing.

[robertisaar]

i moved all of the VE adjustment into the main tables... now the base can't interfere. i thought i copied the main data into the idle table as well... but it appears i didn't?

here is a retouched version.

[tkoforpresident]

LOL sry to make you go through the trouble. I appreciate it.

now i can make my adjustments

[robertisaar]

i expected things like this to happen. if i didn't i would tell people to fork over cash or leave me the hell alone

[tkoforpresident]

i expected things like this to happen. if i didn't i would tell people to fork over cash or leave me the hell alone

rofl

I guess i should admit that im still guilty of that newbie attitude that "one tune will make my car run like new" etc etc

when the reality is that i have all winter to do this and just need to take things one at a time.

[tkoforpresident]

btw, when i just run the BLM "0" cell data through fuel trim i get something interesting (attached to post)

the changes that want to be made in the lower rpms look decidedly different than the ones wanted by "conglomerating" both the BLM cell 0&1.

for instance in the "combined" adjustments sheet it has for 1200 rpm @ 40kpa an adjustment number of .782

while in the same cell (1200 rpm @ 40kpa) for the adjustment sheet with only the "0" table run through fuel trim the adjustment calls for .464


thats quite a difference right?

So lets say for now i just want to tune idle as best i can (since i can't even drive it at the moment) is this the best way to do it by only using the "0" BLM cells as viable data?

And if so, do you use the new adjustments in both the Main VE AND Idle VE or just exclusively in the Idle VE table? (think you said something about making them the same values or i'll be chasing my tail...)

[robertisaar]

if you change JUST the idle table, then the only thing will be changed is when it's doing just that. as soon as there is any throttle it can kick out and into the main table, depending on your settings...

me thinks you are thinking about it too much...

the cell 0 data can also have "later data", which is almost always more extreme than "earlier data". that could explain that discrepancy...

[tkoforpresident]

hmm.. well now i don't know which data to use

i could use the newly found "0" adjustments on my lower rpms (think 1200 and below) in both the main VE and Idle VE tables, but use the conjoined data for the upper rpms (think 1600 and up) for both tables. They will then be equal values in both tables but one will be adjusted more for idle (lower rpms) than the other.

would that work/make sense?

The problem i'm having right now is that this idea of "multiple" tables is totally screwing with my brain and i don't know what the correct way to tune VE is. It's so confusing to me, you have no idea. I'm trying to understand but i'm hearing of many "different" ways that i can tune VE but each one has radically different adjustment results than the other one. Is there ONE correct way to do this?

Robert, how would YOU do it if you were in my shoes? I'm getting pretty rattled here. =/