Maf, open loop tuning, which tables, 95 OBD1 using tunercat.
02-08-2012, 03:34 PM
#1
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Join Date: May 2005
Posts: 392
Maf, open loop tuning, which tables, 95 OBD1 using tunercat.
This is for a '95 OBD1 pcm using tunercat. After reading numerous threads I am more confused than ever. I am trying to tune my car using the maf in open loop only using my wideband sensor. I thought I would use the "maf calibration tables" for idle and partial throttle driving. Then use the "% change to afr vs cool. temp at wot" with the "% change to afr vs rpm at wot" to tune wot. I heard these are the power enrichment tables.
Well after reading to much threads I have heard that in maf open loop tuning you need to use the "afr vs cool. temp vs map" to tune wot because supposedly maf open loop tuning won't use the power enrichment tables. Not sure if any of this is true but can anyone help me.
Which tables are effective at doing what if anything in Maf Open Loop Tuning?
1. maf calibration tables
2. % change to afr vs cool. temp at wot" with the" % change to afr vs rpm at wot (power enrichment tables)
3. afr vs cool. temp vs map table
Idle should use -
Partial throttle (cruising) should use-
Wot should use -
Well after reading to much threads I have heard that in maf open loop tuning you need to use the "afr vs cool. temp vs map" to tune wot because supposedly maf open loop tuning won't use the power enrichment tables. Not sure if any of this is true but can anyone help me.
Which tables are effective at doing what if anything in Maf Open Loop Tuning?
1. maf calibration tables
2. % change to afr vs cool. temp at wot" with the" % change to afr vs rpm at wot (power enrichment tables)
3. afr vs cool. temp vs map table
Idle should use -
Partial throttle (cruising) should use-
Wot should use -
02-08-2012, 08:46 PM
#2
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Join Date: Aug 2010
Location: Mount Airy, MD
Posts: 20
Re: Maf, open loop tuning, which tables, 95 OBD1 using tunercat.
The pcm uses the %afr tables for WOT fueling in conjunction with each other. They both have an effect on WOT afr. The MAF tables have an effect on all areas of fueling. Idle, cruise and WOT. The entire table needs to be calibrated properly to ensure a good, efficient and crisp running engine. The lt1 uses a blended fueling strategy. But for now and the purpose of this thread, You can MAF tune and get it "close enough". Take that with a grain of salt.
If your open loop tuning, then you've set the car in open loop. Copy your high octane tables to your low octane table. Set the entire open loop table to an arbitrary but drivable target AFR like 13.2 . Set the WOT enable parameter to a higher number like 70% or higher. When driving the car in this mode be VERY careful to not to make large throttle transitions so we don't run the car lean and burn down the motor(insert your favorite phrase for damaging the engine here).
While datalogging, we want to pay attention to the HZ of the MAF sensor, and the voltage of the A/c pressure sensor. (you did wire the widebands 5 volt output into the signal return to the pcm so you could datalog on the same datastream right?). When you plot the AFR %error, scale the value in the MAF table by the error % to bring the commanded AFR back into line. Return the open loop table to stock, then lower the WOT setting back to stock level and do some snap throttle runs. Make the corrections to the AFR in the RPM table.
I then rough in the transmission tables to get it to drive the way i like it and go VE tune for a while after having made some power pulls that are rich enough to be safe that i can confirm with plug cuts. I of course return the octane tables back to "normal" after making timing adjustments and the scaled differences between low and high octane. I also prefer to run closed loop, but that's me.
Its not THE method, just the one I use. Any feed back or criticism is welcome!
Chris
If your open loop tuning, then you've set the car in open loop. Copy your high octane tables to your low octane table. Set the entire open loop table to an arbitrary but drivable target AFR like 13.2 . Set the WOT enable parameter to a higher number like 70% or higher. When driving the car in this mode be VERY careful to not to make large throttle transitions so we don't run the car lean and burn down the motor(insert your favorite phrase for damaging the engine here).
While datalogging, we want to pay attention to the HZ of the MAF sensor, and the voltage of the A/c pressure sensor. (you did wire the widebands 5 volt output into the signal return to the pcm so you could datalog on the same datastream right?). When you plot the AFR %error, scale the value in the MAF table by the error % to bring the commanded AFR back into line. Return the open loop table to stock, then lower the WOT setting back to stock level and do some snap throttle runs. Make the corrections to the AFR in the RPM table.
I then rough in the transmission tables to get it to drive the way i like it and go VE tune for a while after having made some power pulls that are rich enough to be safe that i can confirm with plug cuts. I of course return the octane tables back to "normal" after making timing adjustments and the scaled differences between low and high octane. I also prefer to run closed loop, but that's me.
Its not THE method, just the one I use. Any feed back or criticism is welcome!
Chris
Last edited by Rocko350; 02-08-2012 at 08:50 PM.
02-19-2012, 10:57 PM
#3
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Thread Starter
Join Date: May 2005
Posts: 392
Re: Maf, open loop tuning, which tables, 95 OBD1 using tunercat.
The pcm uses the %afr tables for WOT fueling in conjunction with each other. They both have an effect on WOT afr. The MAF tables have an effect on all areas of fueling. Idle, cruise and WOT. The entire table needs to be calibrated properly to ensure a good, efficient and crisp running engine. The lt1 uses a blended fueling strategy. But for now and the purpose of this thread, You can MAF tune and get it "close enough". Take that with a grain of salt.
If your open loop tuning, then you've set the car in open loop. Copy your high octane tables to your low octane table. Set the entire open loop table to an arbitrary but drivable target AFR like 13.2 . Set the WOT enable parameter to a higher number like 70% or higher. When driving the car in this mode be VERY careful to not to make large throttle transitions so we don't run the car lean and burn down the motor(insert your favorite phrase for damaging the engine here).
While datalogging, we want to pay attention to the HZ of the MAF sensor, and the voltage of the A/c pressure sensor. (you did wire the widebands 5 volt output into the signal return to the pcm so you could datalog on the same datastream right?). When you plot the AFR %error, scale the value in the MAF table by the error % to bring the commanded AFR back into line. Return the open loop table to stock, then lower the WOT setting back to stock level and do some snap throttle runs. Make the corrections to the AFR in the RPM table.
I then rough in the transmission tables to get it to drive the way i like it and go VE tune for a while after having made some power pulls that are rich enough to be safe that i can confirm with plug cuts. I of course return the octane tables back to "normal" after making timing adjustments and the scaled differences between low and high octane. I also prefer to run closed loop, but that's me.
Its not THE method, just the one I use. Any feed back or criticism is welcome!
Chris
If your open loop tuning, then you've set the car in open loop. Copy your high octane tables to your low octane table. Set the entire open loop table to an arbitrary but drivable target AFR like 13.2 . Set the WOT enable parameter to a higher number like 70% or higher. When driving the car in this mode be VERY careful to not to make large throttle transitions so we don't run the car lean and burn down the motor(insert your favorite phrase for damaging the engine here).
While datalogging, we want to pay attention to the HZ of the MAF sensor, and the voltage of the A/c pressure sensor. (you did wire the widebands 5 volt output into the signal return to the pcm so you could datalog on the same datastream right?). When you plot the AFR %error, scale the value in the MAF table by the error % to bring the commanded AFR back into line. Return the open loop table to stock, then lower the WOT setting back to stock level and do some snap throttle runs. Make the corrections to the AFR in the RPM table.
I then rough in the transmission tables to get it to drive the way i like it and go VE tune for a while after having made some power pulls that are rich enough to be safe that i can confirm with plug cuts. I of course return the octane tables back to "normal" after making timing adjustments and the scaled differences between low and high octane. I also prefer to run closed loop, but that's me.
Its not THE method, just the one I use. Any feed back or criticism is welcome!
Chris
02-20-2012, 04:55 PM
#4
Registered User
Join Date: Aug 2010
Location: Mount Airy, MD
Posts: 20
Re: Maf, open loop tuning, which tables, 95 OBD1 using tunercat.
The main tables are the high octane tables. Yes, you will need to disable things like WOT fueling, EGR, and DFCO. Re-enable them when your done. Then tweek them after its driving the way you like it.
Chris
Chris
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