Fuel trims

[3gEclipseTurbo]

ok so my fuel trims are:

ltft low is -2.8
ltft mid is -8.1
ltft high -.1

my injector latencys are:
3.792
2.784
1.2
0.96
0.672
0.384
0.312

Scaled at 418

[3gEclipseTurbo]

Any suggestions to get my mid ltft closer?

[0xDEAD]

My suggestion would be to save our time and save your time and use the search button.

[3gEclipseTurbo]

Actualy i did and everything is just with the scaling and when i change the scaling it doesnt help

[0xDEAD]

How To Tune an Evo

When I searched using your thread title that came up as the 4th link, with your post cluttering up the results it would have been the third link. Furthermore it is stickied and is the very first thread in this section of the site. Read, absorb, and good luck. If you make another post within 48 hours you haven't read enough, absorbed enough, and experimented enough. If you want spoon fed, this isn't the best place.

People spend a great deal of time making useful posts so that simple ones like this don't need to be made. Its supposed to make your life easier.

[3gEclipseTurbo]

ive read it but it doesnt go into depth on the latency just a link to latency where my injectors are not listed. I found a link to another site but i tryed the latencys for the wrx 440 and my trims went crazy.

[3gEclipseTurbo]

ok so after i read the how to tune a evo again for over the 50th time(seriously) and didnt find anything useful on the latency i search just in the thread and got this

"LTFT (mid) => cruise
LTFT (low) => idle

If low ~= mid & both > 0 then decrease injector scaling
If low ~= mid & both < 0 then increase injector scaling
If low > mid then increase latency values
If low < mid then decrease latency values"

[biggie5252]

That method worked great for me. Adjust in small steps and youll figure it out.

[GST Motorsports]

Originally Posted by 3gEclipseTurbo

ok so my fuel trims are:

ltft low is -2.8
ltft mid is -8.1
ltft high -.1

my injector latencys are:
3.792
2.784
1.2
0.96
0.672
0.384
0.312

Scaled at 418

little more scaling, just a tad more latency

[Dyrexion]

Originally Posted by 3gEclipseTurbo

ok so my fuel trims are:

ltft low is -2.8
ltft mid is -8.1
ltft high -.1

my injector latencys are:
3.792
2.784
1.2
0.96
0.672
0.384
0.312

Scaled at 418

back when i had 440s scaling down to 390 helped in dialing my AFR along with the mid and low ltfts. Anything above that an my car's AFR would idle slightly rough in the 18s with my trims in the +12s. When i ran the modded 440s they would swing alot.

So driving around town alot trying to get them in line i learned that 14/16/18v cells effected my low,11/9 cells, sometimes 7v moved my mid. But i associated the 7 and 4v cells to highs because moving the 11/9v cells made the most difference getting the mid ltft tight. Less than 1% at the least and less than 5% at the most.

Start on the scaling 1st though

[3gEclipseTurbo]

can anyone confirm this?

14v/16v/18v = low ltft
9v/11v = mid ltft
4v/7v = high ltft

[l2r99gst]

There aren't any certain V cells that match to a specific LTFT. That's simple the latency curve based on battery voltage.

LTFT Lo is for lower airflows under a certain Hz value (idle conditions)
LTFT mid is for slight higher airflows (cruising conditions)
LTFT Hi is for very high airflow conditions, which probably won't be met in normal driving

There is a table in your ROM where you can see the crossover points for the LTFTs.

[Dyrexion]

Originally Posted by l2r99gst

There aren't any certain V cells that match to a specific LTFT. That's simple the latency curve based on battery voltage.

LTFT Lo is for lower airflows under a certain Hz value (idle conditions)
LTFT mid is for slight higher airflows (cruising conditions)
LTFT Hi is for very high airflow conditions, which probably won't be met in normal driving

There is a table in your ROM where you can see the crossover points for the LTFTs.

So that means i fell assbackwards in discovering that. Makes sense though because the Hi ltft would never change no matter what i changed them to. works for me tho