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RevGTO
October 20th, 2006, 03:03 AM
I've posted a thread on LS1tech regarding a lean condition being experienced after a header install. http://www.ls1tech.com/forums/showthread.php?t=595099.

My question is about the PE table as discussed in the thread. 0.8 is the stock PE multiplier on the stock EFILive 00 table. 14.63 x .8 = 11.70 - which is the commanded WOT AFR according to EFILive. Other tuning products have a positive factor in this table (i.e. 1.13).

Is this command just factored in opposite ways by different tuning products? And consequently, with EFILive, would you in fact lower the number to command greater enrichment? Thanks for any help.
SSpdDmon
October 20th, 2006, 03:52 AM
The difference is the type of value you're looking at. Fueling can be measured 3 different ways in the exhaust...

AFR - Air-to-fuel ratio (i.e. - 13.0:1)
EQ Ratio - stoich/AFR=EQ (i.e. 14.63/13.0:1=1.125)
Lambda - AFR/stoich=Lambda (usually used w/ WBO2's) (13.0:1/14.63=.889)

Simple algebra shows Lambda=1/EQ... When tuning, just make sure you're 100% certain which values you are using as an extremely lean condition is a mistake nobody wants to make. ;)
TAQuickness
October 20th, 2006, 04:01 AM
The difference is the type of value you're looking at. Fueling can be measured 3 different ways in the exhaust...

AFR - Air-to-fuel ratio (i.e. - 13.0:1)
EQ Ratio - AFR/stoich=EQ (i.e. 14.63/13.0:1=1.125)
Lambda - AFR/stoich=Lambda (usually used w/ WBO2's) (13.0:1/14.63=.889)

Simple algebra shows Lambda=1/EQ... When tuning, just make sure you're 100% certain which values you are using as an extremely lean condition is a mistake nobody wants to make. ;)

I think Lambda = Stoich/AFR
RevGTO
October 20th, 2006, 04:20 AM
The difference is the type of value you're looking at. Fueling can be measured 3 different ways in the exhaust...

AFR - Air-to-fuel ratio (i.e. - 13.0:1)
EQ Ratio - AFR/stoich=EQ (i.e. 14.63/13.0:1=1.125)
Lambda - AFR/stoich=Lambda (usually used w/ WBO2's) (13.0:1/14.63=.889)

Simple algebra shows Lambda=1/EQ... When tuning, just make sure you're 100% certain which values you are using as an extremely lean condition is a mistake nobody wants to make. ;)
Exactly! That's the reason for the post. Apparently LS1edit uses the second formula and EFILive the third. A smaller number in the PE tables on EFILive would make for greater enrichment ... the opposite for programs that use #2.
SSpdDmon
October 20th, 2006, 04:21 AM
I think Lambda = Stoich/AFR

Fixed...I had the EQ backwards.
SSpdDmon
October 20th, 2006, 04:24 AM
Exactly! That's the reason for the post. Apparently LS1edit uses the second formula and EFILive the third. A smaller number in the PE tables on EFILive would make for greater enrichment ... the opposite for programs that use #2.

Well, EFI Live will use which ever one you want. Just to make things easy, I display mine in AFR. That way, I don't have to bother with the quick mental calculations of, "Does an EQ of 1.17=12.5 or 12.6?" Under Edit>Properties, you can change the values on the Display tab. :)
TAQuickness
October 20th, 2006, 04:57 AM
Fixed...I had the EQ backwards.

Yup. I need some coffee
RevGTO
October 20th, 2006, 06:11 AM
Well, EFI Live will use which ever one you want. Just to make things easy, I display mine in AFR. That way, I don't have to bother with the quick mental calculations of, "Does an EQ of 1.17=12.5 or 12.6?" Under Edit>Properties, you can change the values on the Display tab. :)True enough!