PE vs. everything!
Thread Starter
Joined: Nov 2001
Posts: 10,018
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From: Virginia
PE vs. everything! want to ask a few things here to not mess up the other thread
FROM MANUAL*
4.2.12.1 "Temp
This table defines the Power Enrichment (additional fuel) that will be added at WOT vs. the coolant temperature when in PE mode"
anybody prove this? i cant beleive that gm would consider -40*c to be an operational wide open temperature worth programming in.
"4.2.7 Fuel Air Multiplier
The entry in this table is a multiplier. It is used to calculated fuel when there is a MAF failure, or when in Speed Density Mode."
is this coolant temp or intake temp? and is a maxing out the maf frequency considered a 'fail' by the computer?
lastly
4.2.10 "Max Allowed Enrichment
This is a test used in closed loop for maximum enrichment, It does not seem to include PE enrichment."
so if i put a number in th pe table, say 1.5 but have 1.25 on max enrichment. will my enrichment output be 1.25 or 1.5? i was thinking 1.25 but this says otherwise.. if so then what is it good
for?
thanks!
FROM MANUAL*
4.2.12.1 "Temp
This table defines the Power Enrichment (additional fuel) that will be added at WOT vs. the coolant temperature when in PE mode"
anybody prove this? i cant beleive that gm would consider -40*c to be an operational wide open temperature worth programming in.
"4.2.7 Fuel Air Multiplier
The entry in this table is a multiplier. It is used to calculated fuel when there is a MAF failure, or when in Speed Density Mode."
is this coolant temp or intake temp? and is a maxing out the maf frequency considered a 'fail' by the computer?
lastly
4.2.10 "Max Allowed Enrichment
This is a test used in closed loop for maximum enrichment, It does not seem to include PE enrichment."
so if i put a number in th pe table, say 1.5 but have 1.25 on max enrichment. will my enrichment output be 1.25 or 1.5? i was thinking 1.25 but this says otherwise.. if so then what is it good
for?
thanks!
Adkoonerstrator
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From: Deep in the seedy underworld of Koonerville
Re: PE vs. everything! The Fuel air multiplier isn't going to help you no matter what the temp is referencing because it's pressure vs. temp. Our MAP sensors don't read positive pressure above atmoshperic. <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />
Hmmm...Good question about the Max Allowed Enrichment. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
John
<small>[ March 12, 2003, 07:39 PM: Message edited by: XLR8NSS ]</small>
Hmmm...Good question about the Max Allowed Enrichment. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
John
<small>[ March 12, 2003, 07:39 PM: Message edited by: XLR8NSS ]</small>
Thread Starter
Joined: Nov 2001
Posts: 10,018
Likes: 51
From: Virginia
Re: PE vs. everything! you are right, but i was just planning on using the last curve, the 100kpa or whatever it was and tune it rich for my max boost across temp ranges and leave all the other multipliers alone.
is the f/a multiplier coolant or iat?
is the f/a multiplier coolant or iat?
Adkoonerstrator
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Re: PE vs. everything! Alright, I see what you want to do.
I'm going to make an educated guess and say that the temps are the IAT. If you look the multipliers get larger the colder it is which makes sense. Colder air needs more fuel to maintain a given A/F ratio. I don't know for sure though, maybe an email to carputing is in order. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
We know MAF sensors can be recal'd and tricked I wonder if a 2bar MAP sensor could be recal'd to read 100Kpa @ 14.7psig.(basically cut the signal in half) That way you could rework the Fuel Air Multiplier to help compensate for temperature changes and tune for boost changes as long as you didn't go above ~15psi. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Probably easier and maybe cheaper just to wire up an aftermarket engine management system at that point because you'd also need a special MAF setup with 15psi. <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />
John
I'm going to make an educated guess and say that the temps are the IAT. If you look the multipliers get larger the colder it is which makes sense. Colder air needs more fuel to maintain a given A/F ratio. I don't know for sure though, maybe an email to carputing is in order. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
We know MAF sensors can be recal'd and tricked I wonder if a 2bar MAP sensor could be recal'd to read 100Kpa @ 14.7psig.(basically cut the signal in half) That way you could rework the Fuel Air Multiplier to help compensate for temperature changes and tune for boost changes as long as you didn't go above ~15psi. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Probably easier and maybe cheaper just to wire up an aftermarket engine management system at that point because you'd also need a special MAF setup with 15psi. <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" />
John
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From: St Louis, MO
Re: PE vs. everything! There are 2 and 3 bar map sensors and just like our 1 bar they operate 0 to 5V dc. The problem is you'd have to rescale like 2/3 of the tables in the pcm, and what about tables that havent been reverse engineered yet?
Eric
Eric
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Re: PE vs. everything! </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 66ImpalaLT1:
<strong> There are 2 and 3 bar map sensors and just like our 1 bar they operate 0 to 5V dc. The problem is you'd have to rescale like 2/3 of the tables in the pcm, and what about tables that havent been reverse engineered yet?
Eric </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Good points. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
It's just an idea, I never said it was possible(right now) or would be easy. <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />
It would probably be similiar to what Harlan went through reprogramming for his MAF setup.
If one did figure out what table to modify I don't see why it wouldn't work though.
John
<strong> There are 2 and 3 bar map sensors and just like our 1 bar they operate 0 to 5V dc. The problem is you'd have to rescale like 2/3 of the tables in the pcm, and what about tables that havent been reverse engineered yet?
Eric </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Good points. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
It's just an idea, I never said it was possible(right now) or would be easy. <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />
It would probably be similiar to what Harlan went through reprogramming for his MAF setup.
If one did figure out what table to modify I don't see why it wouldn't work though.
John
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Thread Starter
Joined: Nov 2001
Posts: 10,018
Likes: 51
From: Virginia
Re: PE vs. everything! thanks, when the car gets on the road, im going to try and see if that table will adjust my a/f with temp during my 'maf failure' if it does, then ill push further and redo everything the map influences with that sensor.
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Joined: Jan 2002
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From: USA
Re: PE vs. everything! Your mixing PE with true WOT.
You can be in PE even at low TPS, WOT is engine load around 100 Kpa engine load.
So you could be in cold weather and still need a better AFR the P.T lets say pulling
away from a stop light.
RPM table values are large scale AFR change, Temp values are smaller AFR changes
and the two become the math for what AFR the PCM will command during PE just as
the PCM does in part throttle. RPM and Temp translate to an AFR value.
You can be in PE even at low TPS, WOT is engine load around 100 Kpa engine load.
So you could be in cold weather and still need a better AFR the P.T lets say pulling
away from a stop light.
RPM table values are large scale AFR change, Temp values are smaller AFR changes
and the two become the math for what AFR the PCM will command during PE just as
the PCM does in part throttle. RPM and Temp translate to an AFR value.
want to ask a few things here to not mess up the other thread
anybody prove this? i cant beleive that gm would consider -40*c to be an operational wide open temperature worth programming in.
4.2.10 "Max Allowed Enrichment
This is a test used in closed loop for maximum enrichment, It does not seem to include PE enrichment."
so if i put a number in th pe table, say 1.5 but have 1.25 on max enrichment. will my enrichment output be 1.25 or 1.5? i was thinking 1.25 but this says otherwise.. if so then what is it good
for?
thanks!
anybody prove this? i cant beleive that gm would consider -40*c to be an operational wide open temperature worth programming in.
4.2.10 "Max Allowed Enrichment
This is a test used in closed loop for maximum enrichment, It does not seem to include PE enrichment."
so if i put a number in th pe table, say 1.5 but have 1.25 on max enrichment. will my enrichment output be 1.25 or 1.5? i was thinking 1.25 but this says otherwise.. if so then what is it good
for?
thanks!