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engimuneer

GM NON FFV's have FFV Fuel Map

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That was our impression too, but we've gotten amazing (20 fold improvements) in emissions with any of our ethanol/methanol blends. That's with stock and advanced timing. It doesn't seem to matter how you do the timing, alcohol fuels will burn cleaner than gasoline. Even if the GM virtual sensor mis-learns the fuel (treats E85 as E40), the results have still been vastly superior to on E10.

 

Results are from 2007 2.2L Ecotec out of a Cobalt with flex fuel enabled.

940_.pdf

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I've attached a screenshot of EFILive showing the option to enable flex fuel. I've found it in every 07+ GM tune I've looked at and some earlier models (SUV/Trucks). In all my test cases, the vehicle has learned the fuel (whether M60 or E85, same stoichiometry) and performed well.

 

Great work - now go national with these findings under the guise of a conspiracy theory and how GM did the work but government and big oil don't want you to save money on gas.  People will be beating down GM's door to get E85 then

 

Every single GM OEM tune retards the timing while using E85. Many times up to 15 degrees in the cruise zone. Still not sure why you'd retard the timing...

 

NOx

 

PS - should probably split this thread as it stopped being about the chevy volt WAY back.

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this is so encouraging for ethanol.

 

Is it possible on these tunes to also adjust other maps to further increase ethanol's efficiency, taking full advantages of it's unique burning qualities?

 

Since it burns cooler and naturally produces fewer NOx emissions, and since running gas too lean causes increased temperatures and increased NOx emissions...  would it not be safe to say that e85 could be run leaner to account for this?  Could you adjust to run in certain conditions to the leanest you could to run safely and cleanly?

 

Could you adjust the amount of exhaust gas recovery?  Isn't this what thumpn up in the UP is doing on his muscle cars?

 

If so, this could be a pretty good little business installing custom e85 tunes on vehicles...

 

Big question... is it legal?

 

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I said it before, and I'll say it again. 

 

The reason GM doesn't have more FFV cars, is because they took the ethanol percentage sensor out of the system to save money a few years ago. (Saves several hundred bucks per car).

 

And without the sensor, the car's computer does not know what percentage the ethanol content is at. 

 

And without knowing the percentage of ethanol content, the computor cannot calculate, based on oxygen sensor results alone, WHEN to trigger a "lean condition" light on the OBD computer. 

 

And the EPA requires a learn condition light to come on during  a learn condition for gasoline, and also during a lean condition for ethanol, and all combinations of the two.  Without the sensor, the computer won't trigger the light at the proper point.

 

 

 

The problem with that line of thinking is that GM DOES make FFV's without the Sensor....  what am I missing ?

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The problem with that line of thinking is that GM DOES make FFV's without the Sensor....  what am I missing ?

 

That no NEW GM engine / car that is flex-fuel has been added since they removed the sensor. 

 

 

 

 

Umm right off the bat I can think of the NEW 3.6 that's in the Impala and that's FFV..

 

 

BTW James that's where I keep coming up with the 2012 Camaro was going to be FFV.. that LFX was introduced as  FFV engine going in the Imapla , Cadillac SRX, Camaro and a couple others.. I think the Camaro was the only one with that engine that did not "actually" end up  with a  FFV option

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Do these vehicles have a place, perhaps an empty connector, where you could install a fuel sensor?  Then, could it be turned on in the ECU along with flex-fuel capability?  It would seem that GM has already done most of the work.

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What burns me is that my new Focus has got power this and power that. A touch screen entertainment deal in the dash and voice command for cell phone. Probably more stuff that I'll never use that costs a bunch of money and yet it is out of the question to have a real sensor like my 2001 Taurus had to make it Flex Fuel. Talk about misguided priorities our society has.

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It's not a scam and they can be FFV without the fuel sensor if they use a wide band Oxygen sensor instead of a narrow band. It's a $150 part vs the $350 fuel sensor. Many new cars are coming from the factory like this for emissions/MPG. I found this out when the guys were looking at the exhaust setup for the FRS/BRZ and mentioned that Subaru has been using wideband oxygen sensors for several years now. I know Honda has been using this for lean burn and I can think of a couple other cars including GMs that used a factory wideband over 10 years ago.

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