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engimuneer

GM NON FFV's have FFV Fuel Map

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Just verified today that 2011 & 2012 Malibu FFVs & non have the exact same tunes and settings, the only difference being flex fuel is turned off. First time I've looked at FFV maps and had all the ethanol related tables prefilled. GM usually leaves one or two blank that would screw up its flex fuel operation.

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Just verified today that 2011 & 2012 Malibu FFVs & non have the exact same tunes and settings, the only difference being flex fuel is turned off. First time I've looked at FFV maps and had all the ethanol related tables prefilled. GM usually leaves one or two blank that would screw up its flex fuel operation.

 

 

I think we assumed as much but nice to know someone has actually taken a look at the tables..

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"turned off?" 

 

So..how does one "turn it on?"

 

 

Morning James..    Most likely simply has 2 Fuel Maps and you simply select which Map (set of instructions)you want to use.. Dealer most likely wont do it for you but any small shop with tuner could .. here's a good read http://www.ecuplus.com/featmaps.htm

 

 

If it is simply selecting the FFV Map it is something that would literally take a couple minutes..compared  to changing cell data across multiple cells in a  On NON FFV Map .

 

 

engimuneer is that what it is  simply 2 Fuel Maps ..?

 

 

 

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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.

 

I don't really consider it being 2 maps. Instead, GM uses a scalar to alter the gasoline map values. Final Timing = Gasoline high spark + percentage alcohol * flex fuel spark. Same story for compensations.

 

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 with E85 vs advancing it. My best power and mileage results have been with advanced timing over what the stock gasoline values were. So while I do commend GM for putting out FFVs, I believe the tunes are sabotaged from the get go.

post-2534-13894709505_thumb.jpg

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I was smelling that same rat myself...

 

if it has been common ethanol tuning practice, since Sir Henry Ford (don't know if he was ever knighted, but I'll give him credit for it) invented the flex fuel Model T, and had the option of a distillery that you could buy to produce your own fuel... to advance timing when burning ethanol... why would GM be retarding it...

 

No wonder it doesn't perform as well as people would expect.

 

 

If a tune could be intentionally screwed up, could it not be intentionally fixed?

 

If the EPA is all about reducing emissions... I'd think allowing e85 tuners to modify the fuel map to increase fuel efficiency would make them happy...  but probably not until they pay several billion dollars in fees, testing and certification to prove what we all know anyways....

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The only answer I've found as to why to retard with E85 is due to its quicker flame speed; however, I'm also told it burns longer. Either way, 15 degrees of retardation makes a huge difference.

 

Here is one example from an 09 HHR 2.2L, notice the dip? That dip is repeated in every GM FFV tune I've looked at. Sometimes even worse like with the Malibu. Also notice the 'max air flow' arrow, only the back 8 rows (0-28 g/cyl) are ever used with this NA application. For my tunes, I add 4-8 degrees of timing to the existing high spark table and only get a 10-16% loss in mileage with E85. The loss with M60 (same stoichiometry) is only another 2-3% higher, but 30-40% cheaper (unsubsized) to drive on than E10.

 

Spread the word and ask the questions, only way to fight the industry is with real information and not just hearsay.

939_.pdf

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Now, how can the rest of us with "other vehicles" read the fuel maps and make some changes?  Or is the question, where can you find an E85 mechanic to do such work?

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I'm just getting into Ford ECMs but I'm told from Sniper Tuning that any 05+ Ford with a Spanish/Silver/Green Oak ECM should have the same capabilities. I use EFILive & HPTuners for GM but Diablosport's Chipmaster Revolution for Fords.

 

If you've already got the flex fuel related tables filled out in an FFV vehicle, then modification is minimal (like the +4-8 deg advance I do). If you have a non-FFV GM vehicle with FF/ethanol related tables, then some of the tables have been left blank in many cases. Easiest thing to do is compare with a similar year FFV, then cut & paste, followed by doing your own ethanol spark table. If I had your ECM box code, I could probably look at the tables and tell you what's accessible.

 

Chrysler also has FFVs, but I have not looked at their programming as of yet. In 2011, they also went to a new encryption that I think, hasn't been cracked yet.

 

While Toyota does have an FFV, no one is able to tune 05+ Toyota's.

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Bear in mind that Billy drives a Ford Escape hybrid so it's an Atkinson engine.  ;D

 

My first impression of the retarded timing was that it was done to pass emission testing.

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