3800 settings and what to look for
- Thread starter Sinister Drag Designs
- Start date
As close to 0 as possible......
Tune at idle for 0...........then do cruise.......then do WOT.....
You need to give the comp plenty of time to adjust though.....Do idle and set it for a few days.....then go onto cruise and come back a while latter to see if they have changed.......
To many people go to fast through it.
.890-910 IC
.920-30 and you should be good.
Tune at idle for 0...........then do cruise.......then do WOT.....
You need to give the comp plenty of time to adjust though.....Do idle and set it for a few days.....then go onto cruise and come back a while latter to see if they have changed.......
To many people go to fast through it.
.890-910 IC
.920-30 and you should be good.
if your O2 sensors have alot of miles in them or appear lazy switching in the scanner... you may want to shoot even richer and then get it on a dyno with wideband...
Stock narrowband sensors aren't the best gauge for richness (I run 12.8:1 AFR on my TA, narrowband used to show .890 , new O2s show .870 , but wideband is accurate)
I generally use them as a loose guideline, erroring on the side of overly rich and then running the car leaner
Stock narrowband sensors aren't the best gauge for richness (I run 12.8:1 AFR on my TA, narrowband used to show .890 , new O2s show .870 , but wideband is accurate)
I generally use them as a loose guideline, erroring on the side of overly rich and then running the car leaner
ok but my scans are all over the place this mornign at cruise my LTFT was 0 and on the way home it was 3.9 to 4.5 and at idle its at 3.9and if i gun it and let off all the way it goes up to 10.9
and yesturday i was seeing what my o2 were at and they were saying 960 to 950
and today they wont even hit 900
880 to 895
with the LTFT do i add fuel to get to 0 or do i take away id really like a person who is good with these
hey bumpin i know i asked you a couple of times
but would you be able ot tune any time this week
I agree w hoirst too. When I started all that stuff I put in a new sensor to be on the safe side as well.
You need to tune one setting at a time......do idle and dont touch it for a while........the computer will keep trying to figure stuff out and redo things a little.....wait a day or 2 and redo.
Then do it at cruise around 55mph on flat road.....highway late at night works good. Wait a day or 2 and redo.
Just doing those 2 right will pull your WOT down naturally.....then adjust a litlle from there.
I think I remember being at 0 to +2 percent is safe.....stay away from the negative side.
You need to tune one setting at a time......do idle and dont touch it for a while........the computer will keep trying to figure stuff out and redo things a little.....wait a day or 2 and redo.
Then do it at cruise around 55mph on flat road.....highway late at night works good. Wait a day or 2 and redo.
Just doing those 2 right will pull your WOT down naturally.....then adjust a litlle from there.
I think I remember being at 0 to +2 percent is safe.....stay away from the negative side.
Positive LTRIM means it's adding fuel for you, so you want to add fuel to get it back to 0 (increase VE)
Negative LTRIM means the PCM is pulling fuel for you (so you want to remove fuel to get back to 0 (decrease VE)
VE is how efficient the motor is as an air pump basically... Not sure what format your VE table is displayed in (grams/cylinder or as a percentage) but regardless, it's showing you how much useable air is in the cylinder at that RPM and MAP ... more air means you need more fuel , less air means less fuel
only thing I'm not real sure about is Supercharged tuning... I'm not sure how speed density works (if at all?) on supercharged or even V6 applications...
On V8s I disable the MAF (via maf fail frequency) so I go into failover speed density mode... I copy my high octane to low octane timing tables (Speed Density causes you to use the low octane tables)... then I tune based purely on MAP/RPM/IAT w/out having the MAF in there to scew data ...
Then in my situation I've been forcing the car into open loop, disabling PE, and setting the Open Loop Commanded AFR to 13.0:1 and tuning for that across the board via wideband (so I can safely rev to higher rpm and loads) ... once the VE is dialed in I do WOT tuning. Then I enable closed loop again and turn PE back on... Then on some cars i'll reenable the MAF and dial the MAF in (since I know my VE table is pretty well dialed in, any drastic changes must be caused by the MAF skewing the data) ... but this procedure is all with wideband... (i use the % difference between wideband AFR and commanded AFR)
for narrowband I do the same but use closed loop only and I don't push it beyond about 50% throttle (set PE to not turn on till 60%) ... but you loose accuracy w/this method because you can't get to the higher RPM/MAP values since that forces PE to enable and you can't get an exact value w/the narrowbands
But the above is for V8 speed density cars... I'm not sure w/SD and the V6s or more so w/supercharged cars... not sure how safe it is in that situation...
during normal driving ... how fast is your O2 sensor switching? is it fast? or does it seem lazy? I can post an example of fast/lazy in a bit if you'd like
Negative LTRIM means the PCM is pulling fuel for you (so you want to remove fuel to get back to 0 (decrease VE)
VE is how efficient the motor is as an air pump basically... Not sure what format your VE table is displayed in (grams/cylinder or as a percentage) but regardless, it's showing you how much useable air is in the cylinder at that RPM and MAP ... more air means you need more fuel , less air means less fuel
only thing I'm not real sure about is Supercharged tuning... I'm not sure how speed density works (if at all?) on supercharged or even V6 applications...
On V8s I disable the MAF (via maf fail frequency) so I go into failover speed density mode... I copy my high octane to low octane timing tables (Speed Density causes you to use the low octane tables)... then I tune based purely on MAP/RPM/IAT w/out having the MAF in there to scew data ...
Then in my situation I've been forcing the car into open loop, disabling PE, and setting the Open Loop Commanded AFR to 13.0:1 and tuning for that across the board via wideband (so I can safely rev to higher rpm and loads) ... once the VE is dialed in I do WOT tuning. Then I enable closed loop again and turn PE back on... Then on some cars i'll reenable the MAF and dial the MAF in (since I know my VE table is pretty well dialed in, any drastic changes must be caused by the MAF skewing the data) ... but this procedure is all with wideband... (i use the % difference between wideband AFR and commanded AFR)
for narrowband I do the same but use closed loop only and I don't push it beyond about 50% throttle (set PE to not turn on till 60%) ... but you loose accuracy w/this method because you can't get to the higher RPM/MAP values since that forces PE to enable and you can't get an exact value w/the narrowbands
But the above is for V8 speed density cars... I'm not sure w/SD and the V6s or more so w/supercharged cars... not sure how safe it is in that situation...
during normal driving ... how fast is your O2 sensor switching? is it fast? or does it seem lazy? I can post an example of fast/lazy in a bit if you'd like
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