2012 CTS V e85 tuning

[christianreid22]

Hi everyone, I am coming over from the Mopar platform and looking for help getting into this CtS-V.

If I only want to give this car a dedicated tune, can I just swap the injectors? If so which ones are the most common (size).
How would I go about adjusting the fueling for e85 stoich. Is it similar to the Mopar platform utilizing VE tables that control fueling?

Please let me know! Thanks!

[5FDP]

Install a sensor and let the computer adjust the stoich for you. Unless you are running a barrel of E85, the stuff from the gas station is never the same blend.

Install the sensor, wire it and enable it in the calibration. Copy over a flex fuel stoich table and the computer can do the rest for you. But it's still a decent idea to adjust some of the alcohol tables to better use the E85. Like setting commanded eq ratio's for wide open throttle and changing how quickly the sensor starts to change the stoich after a fueling event.

[blindsquirrel]

https://dsxtuning.com/collections/fl...9-2014-cts-v-1

[blindsquirrel]

https://fuelinjectorclinic.com/flow-calculator

screenshot.06-01-2023 19.12.05.png

(43psi because assuming 58psi returnless minus 15psi boost)

[christianreid22]

Install a sensor and let the computer adjust the stoich for you. Unless you are running a barrel of E85, the stuff from the gas station is never the same blend.

Install the sensor, wire it and enable it in the calibration. Copy over a flex fuel stoich table and the computer can do the rest for you. But it's still a decent idea to adjust some of the alcohol tables to better use the E85. Like setting commanded eq ratio's for wide open throttle and changing how quickly the sensor starts to change the stoich after a fueling event.

Is it really that simple to add e85 to these vehicles? Install sensor and “activate” the pcm calibrations to recognize the sensor? How involved is the wiring?

[blindsquirrel]

Is it really that simple to add e85 to these vehicles? Install sensor and “activate” the pcm calibrations to recognize the sensor? How involved is the wiring?

https://dsxtuning.com/collections/fl...9-2014-cts-v-1

[PGA2B]

For injectors most of us use Injector Dynamics. As far as size, take your eventual goal and buy accordingly. That way you won't run out before you reach it. Buy once cry once!

For E:

You need to watch fuel pressure as you will need either upgraded fuel pumps or an Aux fuel pump:

https://dsxtuning.com/collections/au...nt=58595982283

As for the sensor, it is plug and play except for the white "trigger" wire that goes to the ECM and clips into the main wiring harness.

I don't run E so I can't help with a sample tune.

Go over to CTSVOWNERS.COM Tuning section and there is a lot of vehicle specific information over there.

[GHuggins]

There's more to it than just "activating" it. There are several blank tables that need populating and tuning in depending on the mods and how much boost you're running. Not to mention stock pump is only safely good for around 750 to the tires depending on it's age. Stock injectors are only good to 600 to the tires and as you know a must to replace.

[christianreid22]

There's more to it than just "activating" it. There are several blank tables that need populating and tuning in depending on the mods and how much boost you're running. Not to mention stock pump is only safely good for around 750 to the tires depending on it's age. Stock injectors are only good to 600 to the tires and as you know a must to replace.

Thank you for your input. I am looking to take a stock CTS-V and only add e85 to it. From my understanding I just need to swap the injectors and start making adjustments to the tune, correct? In my area, e85 content is 95% of time is above 81%. So not worried about making it a true flex fuel car. Know what I mean?

[GHuggins]

Personally I would add the sensor and tune it in right with the injectors. You'll be a whole lot happier with it when all said and done, plus you'll be able to run whatever fuel need be if all of a sudden no E is available and with things so iffy anymore - well better safe than sorry.

[That_guy]

Thank you for your input. I am looking to take a stock CTS-V and only add e85 to it. From my understanding I just need to swap the injectors and start making adjustments to the tune, correct? In my area, e85 content is 95% of time is above 81%. So not worried about making it a true flex fuel car. Know what I mean?

You will definitely need a step up in injectors, and the tune will need to be calibrated on 93 octane first before running E85. Your E maps are based off the 93 maps, so those have to be done first. And don't get crazy on injectors if you don't plan on adding anything else to the car. An 80lb injector should be plenty for this application as long as flex fuel is all you're planning on adding to the car.

[christianreid22]

You will definitely need a step up in injectors, and the tune will need to be calibrated on 93 octane first before running E85. Your E maps are based off the 93 maps, so those have to be done first. And don't get crazy on injectors if you don't plan on adding anything else to the car. An 80lb injector should be plenty for this application as long as flex fuel is all you're planning on adding to the car.

Thank you. This is all I am planning on doing. So i define need at least 80 lbs injectors and I need the flex fuel sensor added in, correct?

[christianreid22]

Personally I would add the sensor and tune it in right with the injectors. You'll be a whole lot happier with it when all said and done, plus you'll be able to run whatever fuel need be if all of a sudden no E is available and with things so iffy anymore - well better safe than sorry.

Thank you! Looks like this is the route I am going. Is there a table in the file that I have to “””enable””” per se to tell the computer to look for the variations in fuel content?

[Cringer]

Thank you! Looks like this is the route I am going. Is there a table in the file that I have to ???enable??? per se to tell the computer to look for the variations in fuel content?

I recently added a FF sensor to my car and am working on it now. I don't have LSA injectors yet, so I have not added more spark. Here are the changes I made in the tune. Before you get to this point, the FF sensor needs to be installed and the output wire connected to the correct pin on the ECM. For my E38, it is pin #40.



Engine > Fuel > Flex Fuel
[ECM] 201 Flex Fuel: Enabled
[ECM] 20220 Fuel Sensor: Sensor
[ECM] 3145 Default Frequency: 60 Hz

• This field is used if the sensor ever fails: 50 Hz = 0%E; 60 Hz = 10%E; 70 Hz = 20%E; ...; 150 Hz = 100%E
• I'd rather it fail to 10% and pull timing and have the fueling be rich, than default it to a higher E value, making the engine run leaner and with more advance.

[ECM] 3133 Maximum Ethanol Percentage: 100%
[ECM] 3146 Comp Change Thresh: 1%
[ECM] 3147 Delay Volume: .05 liters
[ECM] 3148 Transition Volume: .05 liters


Engine > Fuel > Power Enrich
[ECM] 12403 EQ Ratio (Alcohol): Set this table to the same as the regular gasoline (although bit leaner)


Engine > Fuel > General
[ECM] 12560 AFR Term: edit the final column (percentages), stock the final column is 80%, you should change to 70% since there is little benefit to running any more than E70


Engine > Spark > Advance
[ECM] 12678 Flex Fuel: this is the danger table!

• Zero out this table to start with. Drive around with the existing fuel to make sure your sensor is good to go and no leaks are happening. From there, start add one degree at a time to the .52 and higher rows and interpolate down to the .28 row. Ultimately this table will be the final part of your tuning with E85. I am not sure what the final total timing is safe for on the LSA engine.

[ECM] 12636 Mult vs Composition: (note: final column should be 70%)
.0%: 0.0
10%: 0.0
20%: .20
50%: .50
70%: 1.0


[ECM] 12663 Alcohol Mult: (note: final column should be 70%)
.0%: .000
10%: .125
20%: .250
50%: .625
70%: 1.00


Engine Diag > DTC (some these may not be available on your platform, you may have others, I suggest enabling anything flex fuel related)
P0169: SES enable & 1-MIL on Second Error
P0178: SES enable & 1-MIL on Second Error
P0179: SES enable & 1-MIL on Second Error


Note there may be other options to enable (if your platform supports it). Enable if possible:
Engine Diagnostics > Airflow > Flex Fuel
Fuel Sys > Diagnostics > Flex Fuel > System Diag

Pro-Tip:

• Use the Navigator tool in VCM Editor and type in FLEX to see any other references to flex fuel. You can also do the same using the terms BLEND and ALCOHOL, etc.

After making these changes you will most likely run into issues with cold starts on E blended fuel. I was able to solve this by downloading from the repository the "2012 Chevrolet Caprice PPV" (last 6 digits of VIN are 661917 for reference) file and copying over the following tables:
[ECM] 12437 - Open Loop EQ Ratio Alcohol (Gear/DP)
[ECM] 12438 - Open Loop EQ Ratio Alcohol (PN/SP)
[ECM] 12441 - Open Loop IVT Gain vs. IVT vs. MAP
[ECM] 12683 - Cranking Spark

• I only copied over the rows for cold temps (-40*F to 140*F) since my hot starts were already dialed in.

More cold start info:

• If the PPV settings don't work, you might need to mess around with transient fueling and/or EOIT. See this thread.

[christianreid22]

I recently added a FF sensor to my car and am working on it now. I don't have LSA injectors yet, so I have not added more spark. Here are the changes I made in the tune. Before you get to this point, the FF sensor needs to be installed and the output wire connected to the correct pin on the ECM. For my E38, it is pin #40.



Engine > Fuel > Flex Fuel
[ECM] 201 Flex Fuel: Enabled
[ECM] 20220 Fuel Sensor: Sensor
[ECM] 3145 Default Frequency: 60 Hz

• This field is used if the sensor ever fails: 50 Hz = 0%E; 60 Hz = 10%E; 70 Hz = 20%E; ...; 150 Hz = 100%E
• I'd rather it fail to 10% and pull timing and have the fueling be rich, than default it to a higher E value, making the engine run leaner and with more advance.

[ECM] 3133 Maximum Ethanol Percentage: 100%
[ECM] 3146 Comp Change Thresh: 1%
[ECM] 3147 Delay Volume: .05 liters
[ECM] 3148 Transition Volume: .05 liters


Engine > Fuel > Power Enrich
[ECM] 12403 EQ Ratio (Alcohol): Set this table to the same as the regular gasoline (although bit leaner)


Engine > Fuel > General
[ECM] 12560 AFR Term: edit the final column (percentages), stock the final column is 80%, you should change to 70% since there is little benefit to running any more than E70


Engine > Spark > Advance
[ECM] 12678 Flex Fuel: this is the danger table!

• Zero out this table to start with. Drive around with the existing fuel to make sure your sensor is good to go and no leaks are happening. From there, start add one degree at a time to the .52 and higher rows and interpolate down to the .28 row. Ultimately this table will be the final part of your tuning with E85. I am not sure what the final total timing is safe for on the LSA engine.

[ECM] 12636 Mult vs Composition: (note: final column should be 70%)
.0%: 0.0
10%: 0.0
20%: .20
50%: .50
70%: 1.0


[ECM] 12663 Alcohol Mult: (note: final column should be 70%)
.0%: .000
10%: .125
20%: .250
50%: .625
70%: 1.00


Engine Diag > DTC (some these may not be available on your platform, you may have others, I suggest enabling anything flex fuel related)
P0169: SES enable & 1-MIL on Second Error
P0178: SES enable & 1-MIL on Second Error
P0179: SES enable & 1-MIL on Second Error


Engine Diagnostics > Airflow > Flex Fuel
Note there may be other options to enable in here if your platform supports it. Enable if possible.

An absolute beautiful write up. What a great way to get started. Thank you so much!!!

[Cringer]

An absolute beautiful write up. What a great way to get started. Thank you so much!!!

@christianreid22
FYI I ran into cold start issues that I resolved by copying some factory settings from a Caprice PPV from the repository. I have updated my post with the relevant info should you or anyone else reading this need cold start help.