Question: Pump e85 + Boost

[SheepDog]

Mr. Wengerd told me that his "E85" tune is good down to E65

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[barkingspud]

What’s your reasoning for avoiding flex under boost? Just curious.

Hptuners, you may already know, is missing about 20 tables that are needed to make flex work right on a gen3 coyote or f150 ecoboost.

Flex Fuel is "learned" using inferred logic from O2 feedback. It takes time to learn and from a liability standpoint, I wouldn't want to rely on that in a boosted application. I am not aware of any tuners that would take that risk and tune for Flex Fuel with Boost. N/A...Flex Fuel is fine. If you want to hack your PCM, you could wire in an Ethanol Content Sensor and use that input to automatically "adjust" Ethanol content. I don't know of anyone who's actually done that on a Ford but I have a friend in the Dodge world who does it all the time.

 

[illtal]

What’s your reasoning for avoiding flex under boost? Just curious.

Hptuners, you may already know, is missing about 20 tables that are needed to make flex work right on a gen3 coyote or f150 ecoboost.

How does PCMTec do it in the calibration?
I know they have a way to read thru the CANBUS to make flex work.

 

[barkingspud]

Mr. Wengerd told me that his "E85" tune is good down to E65

Just taking advantage of the Wideband O2's to adjust the STFT's. I wouldn't do that in a max effort boosted application but for tooling around town on ~8 psi is fine IMO

 

[barkingspud]

How does PCMTec do it in the calibration?
I know they have a way to read thru the CANBUS to make flex work.

I'm sure they use an Ethanol content sensor that has input to the PCM.

 

[engineermike]

Flex Fuel is "learned" using inferred logic from O2 feedback. It takes time to learn

Yea, I've tuned mine for flex at 16 psi and watched it learn several times. I've found it works very well but you do have to drive 10 or so minutes at part throttle if you switch to gasoline.

One issue with HPT is that they don't give you access to the fuel system volume parameters and they are zero'd out from the factory. If these are set to zero, a fillup will trigger learning but it will stabilize and lock in before the ethanol even reaches the engine, which presents a dangerous situation. The fuel system volumes prevent it from maturing until the lines are purged.

That said, I have my timing coming in at 50% ethanol learned, which is roughly 12/1 AFR. If I switch to gasoline, I can keep an eye on this and don't floor it until the AFR gauge shows >12/1 because I know it doesn't have the additional timing at that point.

and from a liability standpoint, I wouldn't want to rely on that in a boosted application. I am not aware of any tuners that would take that risk and tune for Flex Fuel with Boost.

I get the liability issue as well.

If you want to hack your PCM, you could wire in an Ethanol Content Sensor and use that input to automatically "adjust" Ethanol content. I don't know of anyone who's actually done that on a Ford but I have a friend in the Dodge world who does it all the time.

I know a couple who have used PCMTec to add a sensor and it feeds the data into the OBD2 port. Pretty neat setup.

 

[engineermike]

How does PCMTec do it in the calibration?
I know they have a way to read thru the CANBUS to make flex work.

@mejohn50 or @Rolls can explain this better than I can. But basically there are two sets of calibration tables loaded into the PCM and the data from the can-bus/obd port is used to weight each set of tables as a function of ethanol content. It's very much the same way Ford does it, but using a sensor to determine the weighting instead of learned stoichiometry.

 

[illtal]

@mejohn50 or @Rolls can explain this better than I can. But basically there are two sets of calibration tables loaded into the PCM and the data from the can-bus/obd port is used to weight each set of tables as a function of ethanol content. It's very much the same way Ford does it, but using a sensor to determine the weighting instead of learned stoichiometry.

Ah, I get it. I hope to get the pcmtec when I get my car back so I can maybe do this with my PCM for FLEX!!!

 

[mejohn50]

How does PCMTec do it in the calibration?
I know they have a way to read thru the CANBUS to make flex work.

The PCMTEC implementation adds another module to the CAN bus. That added module takes the signal from the ethanol content sensor and pipes it to the PCM over the CAN bus. With the Custom OS CAN bus flex fuel enabled, the PCMTEC logic is looking for that signal. Like @engineermike said, the tuner then defines two sets of tables to interpolate between based on ethanol content from the added CAN bus ethanol sensor.

 

[illtal]

The PCMTEC implementation adds another module to the CAN bus. That added module takes the signal from the ethanol content sensor and pipes it to the PCM over the CAN bus. With the Custom OS CAN bus flex fuel enabled, the PCMTEC logic is looking for that signal. Like @engineermike said, the tuner then defines two sets of tables to interpolate between based on ethanol content from the added CAN bus ethanol sensor.

Yea I was looking for how they interpreted the values it reads Via the CAN since there are no tables in for that in the stock PCM. The two new tables is now this is done. Can't wait to try it out.

 

[mejohn50]

Yea I was looking for how they interpreted the values it reads Via the CAN since there are no tables in for that in the stock PCM. The two new tables is now this is done. Can't wait to try it out.

They added logic that allows a tuner to add most any table from the base calibration to the flex fuel system. There is also a tuner-defined blend curve that defines the ramp between the two sets of tables. It’s all very configurable by the tuner.

 

[illtal]

They added logic that allows a tuner to add most any table from the base calibration to the flex fuel system. There is also a tuner-defined blend curve that defines the ramp between the two sets of tables. It’s all very configurable by the tuner.

Do you have the URL to where they lay out what all is needed (parts list) to accomplish this? I had it saved on my phone and now can't find it. I should be getting my car back soon and I want to start using PCMTec on it.

 

[Angrey]

From what I've seen, they have two methods.

IF you have an ethanol sensor, they can reference that signal to apply the appropriate table (I'm hoping it's more than just two tables, as referenced above, the MOTEC has entire 3 dimensional maps for ethanol content as a true flex fuel with boost).

The backup method is that you measure the quality of the fuel at the pump and then select from the interface to direct it to which "tune" or setting you want and then it assumes the content based upon your selection.

In any case, as Mike pointed out above, it SEEMS that the OE PCM framework is capable of managing this through air load and not allowing a blower car to make boost (which is essentially what my MOTEC does) but no tuner is either capable or willing to do it.

Took me quite a bit of head scratching as to how you can rev to 8k on a 2.75" pulley and make little or no boost (without a mechanical bypass or bleed) but I think I've cog'd it at this point. The motor just drinks the air faster than the blower is sending it if you command it to keep the air load lower. So in essence, the air simply passes through the blower faster and never backs up or builds up pressure (forgive me if I've described that crudely or inaccurately).

In any case, it's WONDERFUL now not to have to worry about running out of fuel on long crossings between E85 sources/stations for longer trips.

MOTEC did advise and warn that while it SHOULD be fine on pure 93, probably best not to flog or punish the car with a pulley that makes 19 psi of boost, even though it's being managed. So it's essentially a limp backup.

I don't plan on ripping the car on anything less than E70, just nice to have the option to not endanger the motor if I get into a jam and need to limp awhile to get to some E. (or if the E quality is low, which happens from time to time).

This whole approach kinda ties part and parcel to the idea of traction/torque management which is the next layer.

True "flex" systems can also employ a proactive approach and NOT let the vehicle make more torque than you know the wheels/tires can handle for a given RPM and gear/multiplication. And this is crucial to any REAL and effective boost by gear or torque management. So the same approach can be made to manage both desires, protecting the motor AND limiting the car to what traction will permit.

 

[mejohn50]

Do you have the URL to where they lay out what all is needed (parts list) to accomplish this? I had it saved on my phone and now can't find it. I should be getting my car back soon and I want to start using PCMTec on it.

I used to have it but the link isn’t working for me. If you search around on their forums I think you’ll be able to find a list of what you need

The most important thing you need is a Zeitronox ECA-2 CAN ethanol sensor kit. It comes with the sensor and appropriate CAN bus box. It also needs to be programmed correctly, which isn’t hard it just needs to be done.

I’ll have to work on a write up or video showing what I did. I had a custom bracket made to mount the Radium flex fuel sensor adapter.

 

[mejohn50]

IF you have an ethanol sensor, they can reference that signal to apply the appropriate table (I'm hoping it's more than just two tables, as referenced above, the MOTEC has entire 3 dimensional maps for ethanol content as a true flex fuel with boost).

It's almost every table available in the calibration. There are a few exceptions, but for the most part it's *ANY* tables available in the cal. It just gives us access to two sets of the tuner-selected tables and then one set can be calibrated for pump gas and the other set for E85. It just interpolates between those two sets of tables based on the tuner-defined blend curve. Super easy to set up and works quite well.

The backup method is that you measure the quality of the fuel at the pump and then select from the interface to direct it to which "tune" or setting you want and then it assumes the content based upon your selection.

The ethanol content can be managed manually with the PCMTEC logic, but it's not individual tunes. It's interpolation between two sets of tables just like the CAN bus flex fuel does it, the user is just manually setting the value rather than the sensor input. This still leaves the 5 total tune slots (launch slot, base tune, and three additional switchable slots) available to do whatever the tuner wants. It just creates two sets of the selected tables for each tune slot that the tuner can configure based on fuel type as required. If a tuner wanted, they could have one tune slot be pump gas and another be E85 or race gas or whatever, but that's a waste of a tune slot. The manual logic can even be made to work with race gas or octane booster, it just depends on how it's set up. I said it before in my Custom OS thread...the logic PCMTEC has added brings stock gen 3 PCM closer to the capabilities of a stand alone PCM.

In any case, as Mike pointed out above, it SEEMS that the OE PCM framework is capable of managing this through air load and not allowing a blower car to make boost (which is essentially what my MOTEC does) but no tuner is either capable or willing to do it.

The OEM framework can do it. Every parameter to do it is there and it works. Why aren't the tuners doing it? I assume money and ease of work. The more factors you start adding to the mix, the more time they have to spend doing actual tuning and the more chances there are for end users to be confused or to get something wrong.

MOTEC did advise and warn that while it SHOULD be fine on pure 93, probably best not to flog or punish the car with a pulley that makes 19 psi of boost, even though it's being managed. So it's essentially a limp backup.

I tested the OEM load limiting logic at WOT repeatedly with a pulley that (some say) is too small for pump gas on a 12:1 engine and it held my load value quite accurately. I trust the OEM load limiting logic to work 100%. I plan to use it once I get my CAN bus flex fuel dialed in this spring.

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