Tuning entire VE table with PE disabled????
05-24-2013, 09:44 PM
#21
I mean heck, if you want to run full load/full throttle without any PE then be my guest, it's your engine afterall.
Every single internal combustion engine on this planet has some sort of power enrichment at high loads. But I guess all those engineers are wrong and putting too much fuel into their engines at full thorttle. You're going to prove them wrong now are ya?
Every single internal combustion engine on this planet has some sort of power enrichment at high loads. But I guess all those engineers are wrong and putting too much fuel into their engines at full thorttle. You're going to prove them wrong now are ya?
PE, Power Enrichment, I assumed it was enrichment to increase power output.
05-25-2013, 06:36 PM
#23
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Ford is notorious for disabling PE in there truck calibrations, most all 99-04 f250+ trucks stay in full time narrowband closed loop at WOT
My 2000 Lincoln ls 5spd came from the factory in full time narrowband closed loop
I have tuned many turbo and supercharged vehicles making 500-800rwhp using the narrowbands alone until I get fuel dialed in to reenable PE
Running stoich at WOT will only hurt an engine if it gets too hot, you can always pull out some timing to prevent the engine from hurting itself
Not trying to get into a debate or **** in anyone's soup but it can be done if you know what your doing
My 2000 Lincoln ls 5spd came from the factory in full time narrowband closed loop
I have tuned many turbo and supercharged vehicles making 500-800rwhp using the narrowbands alone until I get fuel dialed in to reenable PE
Running stoich at WOT will only hurt an engine if it gets too hot, you can always pull out some timing to prevent the engine from hurting itself
Not trying to get into a debate or **** in anyone's soup but it can be done if you know what your doing
05-26-2013, 04:26 PM
#24
Even with old school carbureted engines you have better ways to adjust fueling without risking the engine.
Some motors will survive many WOT pulls at stoich, some will not.
Nowadays with cheap widebands available, it makes no sense risking engines using Jackass tuning methods.
Some motors will survive many WOT pulls at stoich, some will not.
Nowadays with cheap widebands available, it makes no sense risking engines using Jackass tuning methods.
05-26-2013, 06:15 PM
#25
1) That table showing 1 second delays, versus throttle angle in the truck calibrations with a 60 second delay absolutely does NOT over ride the 60 second delay. My GM Calibrator friend says it is only to get past the EPA certification. Nothing else. No likely to damage a low compression truck engine with no spark advance, but not a modified passenger car engine.
2) Just because it is a sticky on this website is no reason to subject your engine to that. I don't know (or care) who decides what qualifies to be a "sticky", but.....
2) Just because it is a sticky on this website is no reason to subject your engine to that. I don't know (or care) who decides what qualifies to be a "sticky", but.....
05-26-2013, 08:08 PM
#26
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I used to do this when I had no wideband meter. Set
the tables to all 1.000 EQ, lower the timing and drive
around to get data on rich/lean. Then bump the table
by what you see, and repeat until you like the amount
of error. I did tunes over email for a couple of guys this
way, back when. It worked.
Better tools make this unnecessary. But too many
people believe histograms are truth, when they're
really a stew of good and bad data. There's tools,
and there's tools, and some you're better off not
using if you have the time and skill not to.
But I haven't done this the hard way since I got my
LM-1 many years ago.
the tables to all 1.000 EQ, lower the timing and drive
around to get data on rich/lean. Then bump the table
by what you see, and repeat until you like the amount
of error. I did tunes over email for a couple of guys this
way, back when. It worked.
Better tools make this unnecessary. But too many
people believe histograms are truth, when they're
really a stew of good and bad data. There's tools,
and there's tools, and some you're better off not
using if you have the time and skill not to.
But I haven't done this the hard way since I got my
LM-1 many years ago.
05-28-2013, 10:26 AM
#29
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That's probably because hardly anybody uses the
method; you'd have to have the logging & programming
tool, yet not be able to buy or borrow a wideband
meter.
Now when I was doing this (without "benefit" of this
internet wisdom) I dialed the timing down 10 degrees
across the board which ought to be pretty safe. And
you'd be wanting to keep an eye on knock detects
just in case, and peel off some more advance if you
find any ping.
But nobody works this way if they can help it.
And the missing piece is, you can get to air-mass
fidelity at 14.7:1, but you will not know if you do
or don't have big-end fuel mass fidelity when you
want to command 10-20% more fuel under PE.
The narrowbands are no, zero, no good for that.
The fuel system may or may not be as stiff as
you need (fuel fade is certain, how much is the
question).
Another thing to beware, is that these trim-
based methods depend on a few things that you
don't have a second opinion available, for. Like, a
fuel side error will just get rolled up into the VE
table, blindly, as will any error in the O2 switchpoint
table voltage vs real sensor voltage @ stoich (and
you are looking at about 1 AFR point per 100-150
mV, while you're playing with tenths of a point if
you're real fussy about WOT AFR). If you follow
any of these tuning how-tos as a substitute for a
decent understanding of the machine and what it
wants, and how to figure out the quality of data
you're pushing into a tune modification, you can end
up in a bad place.
And you can chalk up a few burnt A4 transmissions
if that bad place happens to be a kooky-lean VE
table that under-estimates air mass and motor
torque, and you didn't think to toughen that end
of things up.
method; you'd have to have the logging & programming
tool, yet not be able to buy or borrow a wideband
meter.
Now when I was doing this (without "benefit" of this
internet wisdom) I dialed the timing down 10 degrees
across the board which ought to be pretty safe. And
you'd be wanting to keep an eye on knock detects
just in case, and peel off some more advance if you
find any ping.
But nobody works this way if they can help it.
And the missing piece is, you can get to air-mass
fidelity at 14.7:1, but you will not know if you do
or don't have big-end fuel mass fidelity when you
want to command 10-20% more fuel under PE.
The narrowbands are no, zero, no good for that.
The fuel system may or may not be as stiff as
you need (fuel fade is certain, how much is the
question).
Another thing to beware, is that these trim-
based methods depend on a few things that you
don't have a second opinion available, for. Like, a
fuel side error will just get rolled up into the VE
table, blindly, as will any error in the O2 switchpoint
table voltage vs real sensor voltage @ stoich (and
you are looking at about 1 AFR point per 100-150
mV, while you're playing with tenths of a point if
you're real fussy about WOT AFR). If you follow
any of these tuning how-tos as a substitute for a
decent understanding of the machine and what it
wants, and how to figure out the quality of data
you're pushing into a tune modification, you can end
up in a bad place.
And you can chalk up a few burnt A4 transmissions
if that bad place happens to be a kooky-lean VE
table that under-estimates air mass and motor
torque, and you didn't think to toughen that end
of things up.
05-28-2013, 09:08 PM
#30
All good points made here.
I finally set up my wideband tonight and did a quick open loop VE tune, it was off here and there but the highest was about 9 and was only of 3-4 on the wot cells. All in all, yes this works better and is safer, but the other way works to an extent. Using my previous method, I had only dropped PE enrichment to 1.2 before I got nervous.
Now just to figure out how to dial in the MAF table with the wideband.
I finally set up my wideband tonight and did a quick open loop VE tune, it was off here and there but the highest was about 9 and was only of 3-4 on the wot cells. All in all, yes this works better and is safer, but the other way works to an extent. Using my previous method, I had only dropped PE enrichment to 1.2 before I got nervous.
Now just to figure out how to dial in the MAF table with the wideband.
