crunk down the mv on bank1/2 o2
09-09-2004, 06:55 PM
#1
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crunk down the mv on bank1/2 o2 Set them per recommendation to 300/366 on the first 0/2 flow lines.
This i guess makes the car want to seek leaner. The LTFT at 0-2 flow regions seemed off a bit before but now at 0-1.
Any difference? i dunno. I guess if the mpg gets any better or worse i'll post. Most of my cruising in the city is in the 1.6-1.9 airflow speed which is where i think the motor can run leaner and theres no load so lean burn isn't really a problem with ECT's which seemed the same (194 on a warm day after a nice jaunt).
I hope lowering the o2 bank1/2 MV settings is LEANING out the target at 0-2 flow rate. If i read the other dude wrong, please feel free to let me know. maybe i'll gain an mpg, maybe the stink will be less, i saw 0 knock on the histogram after a good bit of driving but will have to put a week in it.
I did lean it out right by decreasing the mvolt values on bank1/2 right? seemed to drive the exact same
This i guess makes the car want to seek leaner. The LTFT at 0-2 flow regions seemed off a bit before but now at 0-1.
Any difference? i dunno. I guess if the mpg gets any better or worse i'll post. Most of my cruising in the city is in the 1.6-1.9 airflow speed which is where i think the motor can run leaner and theres no load so lean burn isn't really a problem with ECT's which seemed the same (194 on a warm day after a nice jaunt).
I hope lowering the o2 bank1/2 MV settings is LEANING out the target at 0-2 flow rate. If i read the other dude wrong, please feel free to let me know. maybe i'll gain an mpg, maybe the stink will be less, i saw 0 knock on the histogram after a good bit of driving but will have to put a week in it.
I did lean it out right by decreasing the mvolt values on bank1/2 right? seemed to drive the exact same
09-09-2004, 07:10 PM
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I've done the same; I also remapped my airflow mode
boundaries based on where I saw idle through highway
cruise mass airflow numbers fall, so I could diddle it more
finely. As I recall the mode/flow table was all up to 15 well
before I would be ready to give up on lean cruise bias.
I haven't burned enough tanks since to judge mileage. Do
notice a more stable idle (I pushed the Mode 0 value way
down and this should lean it out, just like the VE table
reduction but going to the same place, rather than opposing
by trim). In fact it seems that the cam guys might want to
do both - VE for open loop but also reduce the Mode 0
(and maybe 1, 2) O2 targets so the fuel trims get with
the program.
Anyway, definitely a bit leaner in feel, have not logged
to see how much my trims have gone negative nor put
the wideband to it idling to check out the actual AFR.
One of these daze....
I'm also suspecting that messing the mode/flow and the
O2 targets around, might be beneficial to headers cars,
by modeling the O2 sensors' reduced output when cool
(low flow). But I don't have headers. Would be a cool
experiment to do some driveway idling with the wideband
up, and see what the headers cars idle at for AFR, and
if pushing the target to lower voltage makes for good
things.
boundaries based on where I saw idle through highway
cruise mass airflow numbers fall, so I could diddle it more
finely. As I recall the mode/flow table was all up to 15 well
before I would be ready to give up on lean cruise bias.
I haven't burned enough tanks since to judge mileage. Do
notice a more stable idle (I pushed the Mode 0 value way
down and this should lean it out, just like the VE table
reduction but going to the same place, rather than opposing
by trim). In fact it seems that the cam guys might want to
do both - VE for open loop but also reduce the Mode 0
(and maybe 1, 2) O2 targets so the fuel trims get with
the program.
Anyway, definitely a bit leaner in feel, have not logged
to see how much my trims have gone negative nor put
the wideband to it idling to check out the actual AFR.
One of these daze....
I'm also suspecting that messing the mode/flow and the
O2 targets around, might be beneficial to headers cars,
by modeling the O2 sensors' reduced output when cool
(low flow). But I don't have headers. Would be a cool
experiment to do some driveway idling with the wideband
up, and see what the headers cars idle at for AFR, and
if pushing the target to lower voltage makes for good
things.
09-09-2004, 08:11 PM
#3
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can you show us your exact tables please. I want to compare and try yours for shiz n giggles. I dont understand the mode/flow tables. If you can be descript, others will find this helpful. 10-12mpg city sux, i got 20mpg on freeway (not driving slowly either) so i know theres room.
What about scaling the o2 a little higher since we have a stall its likely in street trim we might be able to run leaner too. I would of course probably tweak things a little back for track use, but i forsee little of that these days. It's 99.9% city 0-45 and .01% freeway so i want to maximize.
Please give me a hand hear, examples of tables you changed would be great. I'd like to try what i got and yours and see the difference as weeks go by i eat up gas so quick
i was thinking the headers are a problem too. Maybe i should get some new o2 sensors lol. 72K. bout that time. They react fast and heat up fast so might as well tweak on.
What about scaling the o2 a little higher since we have a stall its likely in street trim we might be able to run leaner too. I would of course probably tweak things a little back for track use, but i forsee little of that these days. It's 99.9% city 0-45 and .01% freeway so i want to maximize.
Please give me a hand hear, examples of tables you changed would be great. I'd like to try what i got and yours and see the difference as weeks go by i eat up gas so quick
i was thinking the headers are a problem too. Maybe i should get some new o2 sensors lol. 72K. bout that time. They react fast and heat up fast so might as well tweak on.
09-09-2004, 09:03 PM
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the hptuner dudes emailed me back (quick! what service!)
the O2mv tables, lower equals leaner. Word of caution here.
The VCM switches the fuel rich and lean around the O2mv tables. If you
try to go lower than 300mv, or higher than 600mv
you will have fueling problems.
Now back to the news you want to hear. GM does this all the time so feel
free to tune those to where you want them.
On the heavy duty truck calibrations they favor the 580mv side for an
overall richer mixture. On some of the smaller cars, they set them
around
375mv.
the O2mv tables, lower equals leaner. Word of caution here.
The VCM switches the fuel rich and lean around the O2mv tables. If you
try to go lower than 300mv, or higher than 600mv
you will have fueling problems.
Now back to the news you want to hear. GM does this all the time so feel
free to tune those to where you want them.
On the heavy duty truck calibrations they favor the 580mv side for an
overall richer mixture. On some of the smaller cars, they set them
around
375mv.
09-09-2004, 09:40 PM
#5
My 300/366 improved the idle a lot. It's still a bit rich, but folks halfway down the parking lot aren't commenting on it anymore. 
I may still try taking the second value down another notch. Haven't quite figured out which one is predominant when idling... I need to get a better handle on this whole airflow mode part of the puzzle.
I may still try taking the second value down another notch. Haven't quite figured out which one is predominant when idling... I need to get a better handle on this whole airflow mode part of the puzzle.
09-10-2004, 04:44 PM
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Attached is a screen shot of the mode/airflow, the
O2 threshold, and the FTC boundary tables I'm using
presently. I had to compress it a lot to hit the 100kB
limit, so it looks a little crappy.
Stock has the mode=16 for everything above 36. This
is a bit short; 50MPH level cruise in 4th with 12% TPS
pulls 24 gm/sec. 65MPH at 18% TPS goes as high as
50 gm/sec. So I expanded the range and put 15% out
to 124gm/sec, 16 at 160 gm/sec. I see about 100 as
the start of "brisk acceleration", about 35% TPS.
So that gives me more space to play in anyway, for
whatever that's worth. I tapered the mode O2 voltage
up a lot more slowly than stock too.
O2 threshold, and the FTC boundary tables I'm using
presently. I had to compress it a lot to hit the 100kB
limit, so it looks a little crappy.
Stock has the mode=16 for everything above 36. This
is a bit short; 50MPH level cruise in 4th with 12% TPS
pulls 24 gm/sec. 65MPH at 18% TPS goes as high as
50 gm/sec. So I expanded the range and put 15% out
to 124gm/sec, 16 at 160 gm/sec. I see about 100 as
the start of "brisk acceleration", about 35% TPS.
So that gives me more space to play in anyway, for
whatever that's worth. I tapered the mode O2 voltage
up a lot more slowly than stock too.
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09-10-2004, 09:50 PM
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yah i just tried them out, i got VE table work fo sho.
Can't tell if its better but logically the o2 system will run the car leaner im guessing.
drives the same to me after uploading it.
thanks !!
Can't tell if its better but logically the o2 system will run the car leaner im guessing.
drives the same to me after uploading it.
thanks !!
09-13-2004, 05:48 AM
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aye jimmy blue, take a good look at the changes in that screen and tell me if they are sposed to decrease 0-35mph mpg? esp closed loop vs airflow (cruise 1.7-2.0 )
09-13-2004, 08:39 AM
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Huh? What screen? Mine?
All I am trying to do it to lean out idle and light cruise.
It should improve MPG but I have yet to put the wideband
to it and only have run through 1 tank since doing it -
which came out a bit higher MPG than usual but my driving
varies a lot as far as the street/highway proportion so I
wouldn't make any MPG claim yet.
The 0-35MPG "should" be improved but by how much,
who knows? I think your super-low city MPG must have
something to do with being always accelerating/decelerating
or just idling a lot. Rolling at 30MPH steady is far different
from 0-30-0-30-0-30 in the vehicle kinetic energy built
and shed.
I was told that table is g/sec indexed, I guess the 1.7-2.0
is your lb/min and that would be like 12-15 g/sec? That
should be using a pretty lean O2 threshold. Should not
decrease MPG (unless that 300mV has bottomed the sensor
and made the loop have problems). Optimum MPG is supposed
to be something like 15.5 - 16:1 as I recall.
All I am trying to do it to lean out idle and light cruise.
It should improve MPG but I have yet to put the wideband
to it and only have run through 1 tank since doing it -
which came out a bit higher MPG than usual but my driving
varies a lot as far as the street/highway proportion so I
wouldn't make any MPG claim yet.
The 0-35MPG "should" be improved but by how much,
who knows? I think your super-low city MPG must have
something to do with being always accelerating/decelerating
or just idling a lot. Rolling at 30MPH steady is far different
from 0-30-0-30-0-30 in the vehicle kinetic energy built
and shed.
I was told that table is g/sec indexed, I guess the 1.7-2.0
is your lb/min and that would be like 12-15 g/sec? That
should be using a pretty lean O2 threshold. Should not
decrease MPG (unless that 300mV has bottomed the sensor
and made the loop have problems). Optimum MPG is supposed
to be something like 15.5 - 16:1 as I recall.
09-13-2004, 02:15 PM
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i think i was talking about the idle mode table you set to start 0 0 0 1 1 ..
Versus stock.
Maybe i misunderstood the purpose of that. I'll report i filled up with gas and will compare mpg. I'll need to tweak my VE table a little more.
Versus stock.
Maybe i misunderstood the purpose of that. I'll report i filled up with gas and will compare mpg. I'll need to tweak my VE table a little more.
09-20-2004, 06:15 AM
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i think the mpg on fwy was better but on street the same. got 22mpg going about 180miles ~80mph on 3.42's (a4) which isnt bad, but street seems dismal maybe my more fun shift points/lockup points i put back in.
09-20-2004, 03:16 PM
#14
Originally Posted by John_D.
My 300/366 improved the idle a lot. It's still a bit rich, but folks halfway down the parking lot aren't commenting on it anymore.
I may still try taking the second value down another notch.
I may still try taking the second value down another notch.
Taking it to 300/325 seems to have done the trick for mine.
09-20-2004, 03:35 PM
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Originally Posted by samz28
i think the mpg on fwy was better but on street the same. got 22mpg going about 180miles ~80mph on 3.42's (a4) which isnt bad, but street seems dismal maybe my more fun shift points/lockup points i put back in.
that won't be halped by the closed loop cruise
fiddling.
