Winter blend gas and E/85

This seems to be coming together for me now...

They must really use the WB 02S for feedback control under heavy load/WOT. And it ties in with the curious choice for a speed density control method. This would explain the appreciable gains from blending ethanol as well, on OE tuning, whereas vehicles which do not utilize feedback control under WOT MUST be tuned for it. Crazy.
Does this date back to 2010 for all 3.5 EB engines, or was there a change in design for 13 plus?

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I added fuel status from torque (monitors closed loop vs open and will see what it does) should have results shortly.

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The car was floored and was in closed loop the entire time all the way through 2nd gear. Which is what I expected due to the wideband o2 sensor.

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There are plenty of WB 02S equipped cars out there which aren't arranged from the factory with a control schematic, utilizing 02S feedback for control loop under WOT.

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The Ecoboost platform does go closed loop at WOT.

Closed loop allows the ECM to learn, compensate, and/or save the engine.

Open loop relies on pre factored tables and when pushing our platform could be dangerous to the engine, since there would be no way for the ECM to learn or compensate for out of range parameters.
 
Well, according to sources here, it doesn't "go" into CL control. It stays in CL almost continously. From what FoMo reported, it only utilizes open loop when the engine is cold, before sensors have heated up. Isn't that correct?

"Save" the engine, assuming 02S feedback data is accurate, and the sensor is reporting at near perfect accuracy. Sensors foul and lose accuracy over use. Is there a failsafe? How does the ECU know 02S is reporting accurate feedback? If there is detection, it has got to fall back to open loop control as a means of protection. I guess in this manner I don't see how closed loop control under heavy load can be considered something safe.





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IHeartGroceries said:
Well, according to sources here, it doesn't "go" into CL control. It stays in CL almost continously. From what FoMo reported, it only utilizes open loop when the engine is cold, before sensors have heated up. Isn't that correct?

"Save" the engine, assuming 02S feedback data is accurate, and the sensor is reporting at near perfect accuracy. Sensors foul and lose accuracy over use. Is there a failsafe? How does the ECU know 02S is reporting accurate feedback? If there is detection, it has got to fall back to open loop control as a means of protection. I guess in this manner I don't see how closed loop control under heavy load can be considered something safe.
Click to expand...

I understood open loop was used for low load situations, and closed loop was used for high load situations.  Perhaps that is a bit generic, but same concept...

Either way, I'd rather have the ECM continuously monitoring and adjusting to keep the vehicle in spec, as Mike B. discovered, the TB slams shut if the ECM thinks something is off....

I don't know how the wideband sensors are for long term accuracy, maybe they do degrade, I'm not sure...
 
Change intervals...definitely something proposed in the aftermarket world, for tuning purposes. Cobb tuning told me years ago to replace the WB 02S in my MS6 before bringing in back to be tuned. It was fouled and reporting inaccurately. But, it's not like a maintenance item you see Ford place in the owners manual.

They do fail. Perhaps not as susceptible as sensors for engines past. But also, consider the inherent richness of DI burn. The soot on tailpipes? And I've seen discussion here of oil leaking past turbo seals and burning into the exhaust on the engines. These produce particles which can foul a sensor. Not to mention they can potentially just fail outright.

I can see the benefit of using feedback under load, say, if fuel pressure drops (for whatever reason) and is unable to maintain demand. In this scenerio, if the engine were at the mercy of open loop fueling, it could have catastrophic consequences. Definitely an advantage in that situation, to have the feedback. But, if a sensor is grossly inaccurate of fails outright under heavy load, it can have the same results!  XD

Anyway, it is just surprising to see from an OEM. I wasn't aware this was taking place, or that the EB was utilizing it. Pretty sweet. It explains things that I never understood. For example, the gains on E, with stock tuning.

By the way, since I've seen the topic of discussion in here involve fuel brands, Shell is rolling out a new proprietary additive formulation. The conversion is taking place now. Not sure how it differs. But, seems important, considering the proprietary additives are the only thing which makes a blend stock gasoline "branded".


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Unless I was lied to, the "branded " label assures certain levels are maintained also. Ethonal, additives,  and can't remember the other I was told....

Rich

 
SHOdded said:
Still coming out under V Power branding?
Click to expand...

AFAIK, their marketing isn't changing.
V-Power was and still is what they call their super. All grades receive the same, "nitrogen enriched" additive. Their super just receives a much higher rate of additive than mid or reg. That's all that gives it its V-Power status. Their dosage rates on V-Power is quite high, compared to other branded supers, eg. Exxon, Chevron, etc..

SHOnUup said:
Unless I was lied to, the "branded " label assures certain levels are maintained also. Ethonal, additives,  and can't remember the other I was told....

Rich
Click to expand...

Well, everybody strives to maintain both product quality and mandated concetrations. Quite often it's the same blendstock going into the Shell station as it is the mom n pop station across the street. It may have come from the same distribution terminal, out of the same tank, out of the same meter...
The difference was the additive - one received a high(er) dosage of a branded proprietary additive, the other received a "generic" or "unbranded" additive, which is typically injected at a concentration not much higher than federally mandated LAC, or lowest allowable concentration.

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I went back and looked over a technical bulletin I received from PQ group about the new additive - it is indeed a different formulation. I'm no chemist, so the changes are like mumbo jumbo to me. So, it remains unclear what effects the revised formulation might have in your engine.

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Playing armchair chemist ain't easy :)  We need to set up some chemists on a cloud computing network to crack the additive code!
 
Any further updates, ecoboostsho?  Still knock-free?  An upcoming paper in SAE regarding the possible mitigation of the pre-ignition (PI)-triggered severe engine knocks at low engine speeds:
http://papers.sae.org/2015-01-0084/

Addresses the possibility that minimizing oil contamination in the combustion chamber is the key.
 
I've been running a mix of E16 and that eliminates any knock under normal running except for an occasional blip. What I have been watching though is right before the car warms up even the lightest throttle can produce what looks like up to 7 degrees if knock. I'm talking barely any throttle...no lugging and on flat ground. This only happens with a coolant temp between 140 and 160 in 5th gear cruising steady state. As soon as the goes closed loop at around 160 it won't knock at all. I can reproduce it every time. I am stumped....it doesn't seem to hurt anything but I'm not thrilled about it.

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