21 LT1 Camaro Flex Tuning Question

[21LT1]

Hello Folks,

First post here.

I have a 21 LT1 and am swapping over to flex fuel. Have installed the sensor and work as a GM Engineer so good there

Question: Where does the Mult4 table come from below? I have looked in both the internet and this forum and nothing to compare to.

Thanks in advance!

Erick.

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EFI Tuning LLC

Tuning Tool: HP Tuners v3.2.x
Platform: 2016 Camaro SS

File: 2016_ss_flex_fuel_baseline.hpt

Changes:

*** required ***
- modified Engine -> Fuel -> General -> Air Fuel Ratio -> Stoich AFR-> Flex Fuel AFRs
- modified Engine -> Fuel -> Open & Closed Loop -> Flex Fuel -> Flex Fuel -> Enabled
- modified Engine -> Fuel -> Open & Closed Loop -> Flex Fuel -> Flex Fuel -> Fuel Sensor -> Sensor
- modified Engine Diag -> DTC's -> P0178 -> Flexible Fuel Sensor Circuit Low -> checked, Error Mode -> MIL on Second Error
- modified Engine Diag -> DTC's -> P0179 -> Flexible Fuel Sensor Circuit Low -> checked, Error Mode -> MIL on Second Error
- modified Fuel Sys -> Diagnostics -> Flex Fuel -> Sensor Diag -> Enable
****************

*** optional ***
- modified Engine -> Spark -> Advance -> Spark Correction -> AFR Correction -> Alcohol -> Gas table
- modified Engine -> Spark -> Advance -> Spark Correction -> IAT Spark -> Mult4 -> [1.00 1.00 0.80 0.50 0.20]
- modified Engine -> Spark -> Advance -> General -> Cranking/Start -> Cranking -> enhanced for Flex Fuel
- modified Engine -> Spark -> Advance -> General -> Cranking/Start -> Alcohol Adder -> timing added for Flex Fuel cold starts
****************

[5FDP]

Are you asking what it's used for, what it does?

Like for example my truck just has a value of 1.00 for all percentages of alcohol content. If you changed it to the values shown it would multiply the timing by that much based on alcohol content. If I'm reading it right it would take say a number of -2 at 50% alcohol content and make it only -1 degree removed based on IAT temp.

I never changed it on my truck when I added a sensor, I didn't have a need to go that far with it.

[nicul15]

what about the injector flow rate alcohol mult? do you fill that in from the e85 truck file?

[5FDP]

I didn't change that table.

[cmitchell17]

We are hoping you have the answers to your questions being a GM engineer haha, it's baffling some of the things you see in the tune file.

And about all the extra ethanol parameters, I copied the over from the truck file, since I am assuming the cars were never calibrated for E85 even though the tables are populated with somewhat plausible, non-zero numbers.

[jlbjr]

I Did the sensor this week. 2016 ZO6 K+N CAI. Gained 55hp E45 with 25 degrees timing top end. Awesome, just did the basic stuff.