Yet another theory on how to tune...
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From: Commerce Twp, MI
Yet another theory on how to tune... I've been experimenting with a few things lately and had some results I thought I'd share. It came to me originally when looking at a tune that a known shop in Indiana did (name rhymes with flingin' shelter 
) on my dad's car. But, more recently I got to thinking about it again in one of the other threads that was big the last couple of weeks. Back to my dad's car - they had dropped the VE/MAF blending threshold (B0120) down to 400rpm from the factory 4,000rpm setting. Then, they proceeded to do the typical, old-school IFR tune. Now, I'm not too keen on IFR tunes myself. So, I didn't adjust for anything other than my SVO 30's there. What I did do was tweak the MAF curve for my SLP MAF, which oddly enough didn't need too much tweaking. Keep in mind my VE table is stock (that's right - no VE tuning!) and I'm running a healthy H/C setup. The new MAF threshold combined with a relocated IAT sensor (to avoid the heatsoak my lid produces during low airflow scenarios) has produced great results after only ~5 or so rinse & repeats. A few more details (including the BEN's from my drive into work this morning) can be seen in the thread over at the EFI Live forums.
http://forum.efilive.com/showthread....9627#post49627
As I said there....if things keep heading in this direction, I don't think I'll touch another VE again.
My previous lean transitions are gone (now slightly rich on tip in), my AFR%Error is pretty much (-3%)~(1%), and I don't see anymore leaning out while waiting for my burger sitting in the drive-thru for 5 minutes on a hot, summer day. 
Note - Transitions, DFCO, and cells with less than 5 hits have been filtered out of my AFR%Error map below. Commanded AFR is 14.63 unless PE is active, which puts WOT at 12.5~12.8.
) on my dad's car. But, more recently I got to thinking about it again in one of the other threads that was big the last couple of weeks. Back to my dad's car - they had dropped the VE/MAF blending threshold (B0120) down to 400rpm from the factory 4,000rpm setting. Then, they proceeded to do the typical, old-school IFR tune. Now, I'm not too keen on IFR tunes myself. So, I didn't adjust for anything other than my SVO 30's there. What I did do was tweak the MAF curve for my SLP MAF, which oddly enough didn't need too much tweaking. Keep in mind my VE table is stock (that's right - no VE tuning!) and I'm running a healthy H/C setup. The new MAF threshold combined with a relocated IAT sensor (to avoid the heatsoak my lid produces during low airflow scenarios) has produced great results after only ~5 or so rinse & repeats. A few more details (including the BEN's from my drive into work this morning) can be seen in the thread over at the EFI Live forums.http://forum.efilive.com/showthread....9627#post49627
As I said there....if things keep heading in this direction, I don't think I'll touch another VE again.
My previous lean transitions are gone (now slightly rich on tip in), my AFR%Error is pretty much (-3%)~(1%), and I don't see anymore leaning out while waiting for my burger sitting in the drive-thru for 5 minutes on a hot, summer day. Note - Transitions, DFCO, and cells with less than 5 hits have been filtered out of my AFR%Error map below. Commanded AFR is 14.63 unless PE is active, which puts WOT at 12.5~12.8.
Last edited by SSpdDmon; Jun 18, 2007 at 02:51 PM.
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From: Detroit, Murder City
By reducing that threshold, you've effectively made it a "straight from the MAF" calibration under all conditions. At this point, as long as your IFR and MAF values are correct, it should run pretty well. The trick is that sometimes the MAF signal is affected by pulsations from the engine at low speed (and even more so at low speed with high TP%) that may lead to errors.
In short, you've turned it into a Ford.
Don't worry, it's still a legitimate approach.
In short, you've turned it into a Ford.
Don't worry, it's still a legitimate approach. Thread Starter
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From: Commerce Twp, MI
Originally Posted by turbolx
In short, you've turned it into a Ford. Don't worry, it's still a legitimate approach.
Don't worry, it's still a legitimate approach. there is also other ways to do the same effect.
as i said in my other post here a few days ago....you know how the computer controls fuel and such and what tables are used... there are so many damn ways to skin a cat...which way is the right way
as i said in my other post here a few days ago....you know how the computer controls fuel and such and what tables are used... there are so many damn ways to skin a cat...which way is the right way
The "right way" is to have your commanded airfuel = your actual airfuel ratio. IF it does not match, your not tuning correctly. period.
as long as you get to this point, your probably doing it correctly.
Ryan
as long as you get to this point, your probably doing it correctly.
Ryan
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From: Commerce Twp, MI
Originally Posted by slow
The "right way" is to have your commanded airfuel = your actual airfuel ratio. IF it does not match, your not tuning correctly. period.
as long as you get to this point, your probably doing it correctly.
Ryan
as long as you get to this point, your probably doing it correctly.
Ryan
BEN=WBO2/Commanded_AFR <<< 1.00's are good.
I agree... I've been playing around with your method for the past 2-2.5 years on my 1998 Ws6, with good results. 
I am used to tuning the Fords, so that method is just logical in my opinion. Now what I would like to do is backwards populate the VE table with good MAF data, that would be the key.
Ryan
I am used to tuning the Fords, so that method is just logical in my opinion. Now what I would like to do is backwards populate the VE table with good MAF data, that would be the key.
Ryan
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From: Commerce Twp, MI
Originally Posted by slow
I agree... I've been playing around with your method for the past 2-2.5 years on my 1998 Ws6, with good results.
Originally Posted by slow
I am used to tuning the Fords, so that method is just logical in my opinion. Now what I would like to do is backwards populate the VE table with good MAF data, that would be the key.
Ryan
Ryan
Hey Marcin - We need a formula!
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Originally Posted by turbolx
In short, you've turned it into a Ford. Don't worry, it's still a legitimate approach.
Don't worry, it's still a legitimate approach.SSpdDemon, that formula is done, you've had it for months.
the problems you're talking about all sound like wrong temperature biasing, whether you wanna blame heatsoak or whatever else, we have a way to account for it.
the whole method you've described i think i've told PurplePiss to do months ago on his LS2, as the VE tuning on these is in diapers still. I dont think he followed through with it as far as you did, so congrats on your ford conversion.
nothing wrong with it mate, i'm glad someone did it empirically, i'm still stuck in school, but what you did will help me verify some other things for the new ecu's so no work been wasted.
actually, if you wanna use a bitchin formula using your newfound MAF stableness (is that even a word? oh well, it is now...) do this:
k=ln((GMVE*RPM*CYL*MAP-120*MAF*IAT)/(120*MAF*(ECT-IAT)))/-MAF
if you dont have GMVE just use GMVE=VE*CYLVOL/R with R=287.05
use metric everwhere of course
and let's see how k looks like across as much airflow conditions as possible (although it really matters most only < 150g/sec)
enjoy!
k=ln((GMVE*RPM*CYL*MAP-120*MAF*IAT)/(120*MAF*(ECT-IAT)))/-MAF
if you dont have GMVE just use GMVE=VE*CYLVOL/R with R=287.05
use metric everwhere of course
and let's see how k looks like across as much airflow conditions as possible (although it really matters most only < 150g/sec)
enjoy!
I've seen several tuners go about it this way...whatever works. I've seen tuners do it so many ways now you can't really say theres a right or wrong way to do things. In the end its whatever works for a particular application.
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From: Commerce Twp, MI
Originally Posted by RedHardSupra
actually, if you wanna use a bitchin formula using your newfound MAF stableness (is that even a word? oh well, it is now...) do this:
k=ln((GMVE*RPM*CYL*MAP-120*MAF*IAT)/(120*MAF*(ECT-IAT)))/-MAF
if you dont have GMVE just use GMVE=VE*CYLVOL/R with R=287.05
use metric everwhere of course
and let's see how k looks like across as much airflow conditions as possible (although it really matters most only < 150g/sec)
enjoy!
k=ln((GMVE*RPM*CYL*MAP-120*MAF*IAT)/(120*MAF*(ECT-IAT)))/-MAF
if you dont have GMVE just use GMVE=VE*CYLVOL/R with R=287.05
use metric everwhere of course
and let's see how k looks like across as much airflow conditions as possible (although it really matters most only < 150g/sec)
enjoy!
RPM, MAP,MAF,IAT,ECT, and GMVE or VE (there should be a new MPID, if it's not avilable for your PCM please bug Chris@HPT or Paul@EFILive)
the rest is constants:
R=287.05
CYL=8
CYLVOL=.708125 or whatever your cylinder displacement is.
custom pid is probably impossible, as i dont think either tuning package does natural logarithms IIRC. so for now just dump this stuff to excel and do it there, or just send me the log (but that will be done friday at the earliest)
the rest is constants:
R=287.05
CYL=8
CYLVOL=.708125 or whatever your cylinder displacement is.
custom pid is probably impossible, as i dont think either tuning package does natural logarithms IIRC. so for now just dump this stuff to excel and do it there, or just send me the log (but that will be done friday at the earliest)
Originally Posted by SSpdDmon
I've been experimenting with a few things lately and had some results I thought I'd share. It came to me originally when looking at a tune that a known shop in Indiana did (name rhymes with flingin' shelter ) on my dad's car. But, more recently I got to thinking about it again in one of the other threads that was big the last couple of weeks. Back to my dad's car - they had dropped the VE/MAF blending threshold (B0120) down to 400rpm from the factory 4,000rpm setting. Then, they proceeded to do the typical, old-school IFR tune. Now, I'm not too keen on IFR tunes myself. So, I didn't adjust for anything other than my SVO 30's there. What I did do was tweak the MAF curve for my SLP MAF, which oddly enough didn't need too much tweaking. Keep in mind my VE table is stock (that's right - no VE tuning!) and I'm running a healthy H/C setup. The new MAF threshold combined with a relocated IAT sensor (to avoid the heatsoak my lid produces during low airflow scenarios) has produced great results after only ~5 or so rinse & repeats. A few more details (including the BEN's from my drive into work this morning) can be seen in the thread over at the EFI Live forums.
http://forum.efilive.com/showthread....9627#post49627
As I said there....if things keep heading in this direction, I don't think I'll touch another VE again. My previous lean transitions are gone (now slightly rich on tip in), my AFR%Error is pretty much (-3%)~(1%), and I don't see anymore leaning out while waiting for my burger sitting in the drive-thru for 5 minutes on a hot, summer day.
Note - Transitions, DFCO, and cells with less than 5 hits have been filtered out of my AFR%Error map below. Commanded AFR is 14.63 unless PE is active, which puts WOT at 12.5~12.8.
) on my dad's car. But, more recently I got to thinking about it again in one of the other threads that was big the last couple of weeks. Back to my dad's car - they had dropped the VE/MAF blending threshold (B0120) down to 400rpm from the factory 4,000rpm setting. Then, they proceeded to do the typical, old-school IFR tune. Now, I'm not too keen on IFR tunes myself. So, I didn't adjust for anything other than my SVO 30's there. What I did do was tweak the MAF curve for my SLP MAF, which oddly enough didn't need too much tweaking. Keep in mind my VE table is stock (that's right - no VE tuning!) and I'm running a healthy H/C setup. The new MAF threshold combined with a relocated IAT sensor (to avoid the heatsoak my lid produces during low airflow scenarios) has produced great results after only ~5 or so rinse & repeats. A few more details (including the BEN's from my drive into work this morning) can be seen in the thread over at the EFI Live forums.http://forum.efilive.com/showthread....9627#post49627
As I said there....if things keep heading in this direction, I don't think I'll touch another VE again.
My previous lean transitions are gone (now slightly rich on tip in), my AFR%Error is pretty much (-3%)~(1%), and I don't see anymore leaning out while waiting for my burger sitting in the drive-thru for 5 minutes on a hot, summer day. Note - Transitions, DFCO, and cells with less than 5 hits have been filtered out of my AFR%Error map below. Commanded AFR is 14.63 unless PE is active, which puts WOT at 12.5~12.8.
There are a ton of ways to tune.I've been doing the IFR/MAF tuning for years on smaller setups and even a few 700+hp cars with good results. Some cars get SD,Some get MAF tunes.Depends on the setup.
Nobody has proved that doing the IFR table is the wrong way to tune.