shaneSS

iTrader: (2)

Ok My LTFT's on bank s 1 -vs- bank 2 are kinda far off eachother. My question is, am I supposed to get my LTFT's to a stable zero or will there ALWAYS be some off balance between the banks and will you never get it to a stable 0 ?

Here is what I did:

I have a 232/595 cam w/ LS6 Intake / Ported MAF / Headers / etc / EFILive V6.x / LS1 Edit.

I started by changing the VE table in the 400, 800 and 1200 columns and also the IAC in gear and out of gear tables. THe car idles ok for now but my IAC counts are still 60 - 70 range instead of the 30 - 50 I was hoping for but I dont want to drill the butterfly unless I really need to. I also added timing down low to help idle.

I added %5 to my MAF table across the board to get these LTFT values :

Cell# Bank-1 Bank-2
0 0.98% 0.98%
1 1.95% 4.88%
2 0.00% 0.00%
3 0.00% 0.00%
4 -1.95% -0.98%
5 -1.95% 0.98%
6 0.00% 0.00%
7 0.00% 0.00%
8 2.93% 1.95%
9 0.00% 1.95%
10 0.00% 0.00%
11 0.00% 0.00%
12 0.98% 0.98%
13 0.00% 0.98%
14 0.00% 0.00%
15 0.00% 0.00%
16 0.00% 0.00%
17 0.00% 0.00%
18 0.00% 0.00%
19 -0.98% -2.93%
20 0.00% -0.98%
21 -1.95% -2.93%
22 -5.86% -3.91%

I started with the MAF table because A. I have a ported MAF and B. because it seems to make sense to me?...?....

So..... I then tried changing the VE table in the areas (MAP -vs- RPM) for each cell I needed a change in. I added 100+ percent to all cells that were still positive. (So for example, to accomodate for FTC #8 above I multiplied the cells in MAP 60-75 and from 400-2400 RPM by 103%). I did this for all positive cells. (is that the best way to tell what to multiply by when banks 1 and 2 are off? i just averaged them out to 2.5% and upped it to approx 3%)

I then drove around and logged these ltft averages :

Cell# Bank-1 Bank-2
0 0.98% 1.95%
1 -0.98% 2.93%
2 0.00% 0.00%
3 0.00% 0.00%
4 -3.91% 0.00%
5 1.95% 3.91%
6 0.00% 0.00%
7 0.00% 0.00%
8 1.95% 0.00%
9 1.95% 0.98%
10 0.00% 0.00%
11 0.00% 0.00%
12 0.00% 1.95%
13 1.95% 0.98%
14 0.00% 0.00%
15 0.00% 0.00%
16 0.00% 0.00%
17 0.00% 0.00%
18 0.00% 0.00%
19 0.00% 0.00%
20 0.00% 0.00%
21 -3.91% -0.98%
22 0.00% 0.98%

Shouldnt I set the VE table back where it was for the first log and try and adjust the MAF table further before fine tuning the VE? How can I know where in the MAF will effect what FTC #? I tried by MAF frequency since thats what the MAF is in but each FTC had MAF FREQ reading that range 4k apart. SO for example in my FTC 12 I see anwhere from 2900 Hz to 4700Hz. Where in teh MAF table do I change for FTC 12 then?

I am running a 2000 FTC boundry map so I dont see all the FTC's as you pre 2000 guys do. Should I change to a pre 2000 FTC boundry map for more detaile tunning capabilities?


ALl help is appreciated guys.

GrannySShifting

iTrader: (10)

I hardly EVER fool with the maf curves. Move the whole curve maybe, but not bits and peices of it. 90% of the time I say go get stock unport MAF ends, as they arent making any more power for you just makes tuning slightly more time consuming, but it shoudlnt present much problem.

Also, i dont aim for 0% fuel trims. I prefer -2 to -5, so on the days whres its the leanest it shouldnt creep positive on you

shaneSS

iTrader: (2)

THanks,

Im back off to tune some more today. So having B1 and B2 LTFT read different as aboce is normal and I shoudl always just address the most positive value wehater its B1 or B2?

ALso do you see any advantage in changing my LTFT boundry map to the one that gives me all Cells instead of just a few? If so, does anyone have the values for that MAP?

Here is what I am reffering to:

My map looks like this because of my set LTFT boundries :
http://66.95.41.251/images/few-cells.JPG

Other peoples maps look like this which seems to have more tuning granularity:

http://66.95.41.251/images/all-cells.JPG
THanks again

WAHUSKER

iTrader: (4)

The problem is the MAF ends DO make a difference. About .25 sec in the 1/4 mile, as proven on 2 different cars up here in Seattle. I've been wondering what to tweak myself, specifically the MAF curve. But so far I only messed with the VE table in the lower cells.

It is odd that bank 1 doesn't track bank 2. I wonder if a sensor is hosed up?

jimmyblue

iTrader: (11)

You can get the lean-out effects more properly by the
PE vs RPM table, where the factory says 1.25 (11.7:1)
you can (with proper sensor calibrations) command 1.15
(12.7:1) and get it. Ditto the spark advance, move the
values for the true CylAir point, don't tell it the CylAir is
less than actual (via unmodeled hardware).

Truth in calibration, means your commands are the law.

shaneSS

iTrader: (2)

THanks Jimmyblue,

Basically I can definitly tell the difference with the Ported ends -vs- non ported. I just did a %5 scale on the whole table and it made a huge difference in my positive LTFT's But now Im trying to make more fine adjusments to the LTFT's and having some wierd results when I modify the VE table. I thought that you shoudl never really have to adjust any 1 specific cluster in teh VE table greater than 5% (other than 400 800 1200 columns). Is this true or can i make adjustments to the VE as much as needed?

Here is what I did:

I added %5 to the MAF table as stated above which brought my LTFT's more in range (however some went negative and some just went just less positive). At that point I knew that I needed to make adjustments to targeted FTC's thats where I went for the VE table.

So I logged 20 to 30 minutes of data and would then modify the VE table in the cells that were in need per the data in EFILive => LS1/LS6 => Long Term Fuel Trim Cells.

I changed groups of cells in the VE table for a targeted FTC based on this chart I found on ls1tuning.com, (here is a snippet of the chart) : http://66.95.41.251/images/few-cells.JPG

My questions at this point are:

- Is this chart correct as for where to adjust in relation to a FTC (It seems to match my LTFT boundries)

- SHoudl I change my LTFT boundrie to a pre 2000 car where I can see all cells 0-15 as apposed to what Im stuck with above.

- ALso i find it strange that my WOT LTFT is now negative. What would cause LTFT to go - at WOT?

Here is a list of my averages as they sit now.

Cell# Bank-1 Bank-2
0 0.00% 4.88%
1 -3.91% 0.98%
2 0.00% 0.00%
3 0.00% 0.00%
4 0.00% 0.00%
5 1.95% 5.86%
6 0.00% 0.00%
7 0.00% 0.00%
8 3.91% 3.91%
9 3.91% 3.91%
10 0.00% 0.00%
11 0.00% 0.00%
12 1.95% 1.95%
13 1.95% 4.88%
14 0.00% 0.00%
15 0.00% 0.00%
16 0.00% 0.00%
17 0.00% 0.00%
18 0.00% 0.00%
19 0.00% -4.88%
20 -0.98% -1.95%
21 -3.91% -5.86%
22 -3.91% -2.93%


Any help is appreciated guys. I am also getting 3.69 of KR that I need to address.

GrannySShifting

iTrader: (10)

MAF ends are not going to make a difference in his car, unless it is a result of changing the fueling in the car at WOT. Both tuned properly, a ported stock MAF will not run .25 faster then the stock maf, Im sorry. I picked up 2.5 mph with one too. Then I put the stock maf on the car, tuned it, and was at the same mph. MAF is not a restriction in his setup.

Yes I would move the boundaries around, especially the lower one so it catches your idle rpm. You have it idling at 850-925 rpm correct?

KySilverado

iTrader: (7)

I was hoping someone would touch upon your unbalanced LTFT's. I have the same condition in my truck. I don't understand why nor how to proceed with my tuning. All feedback from the O2's are fairly equal yet the tune fuels one side much more via FT's?

shaneSS

iTrader: (2)

NoGo stated to me that seeing this is not uncommon and that unless they are getting close to 10% difference between bank1 and bank2 then just average the two out and tune for that #. I am going to play with this tonight. I may put the stock MAF ends back on just as a test too.

GrannySShifting

iTrader: (10)

they rarely match exaclty, different exhaust setups, cylinders burn sslightly different, different conition o2 sensors etc etc Logs they are within a few percent