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I've been thinking about this for some time, but thought I'd ask those of you tuners and builders out there...

 

If "lean burn" is a no-no these days for gas engines due to increased NOx emissions, and the fact that this burn is too hot, and can damage engine if I'm not mistaken...

 

Wouldn't the fact that e85 combustion produces less NOx and burns cooler then gasoline counter this?

 

Could not a dedicated e85 only engine be tuned to burn leaner, increasing mileage and NOT burn too hot or emit too much NOx?

 

Could they not simply adjust the computer tuning peramiters to run leaner  on e85 then on gas?  Or do they already do this?

 

I still think that current FFVs could have a LOT more tuning done to them to increase e85 mileage and lessen, if not remove the ethanol penalty for efficiency compared to gas.

 

I think that this would be a great grant for Growth Energy to fund...

 

Work with say Ford, and give 10 different land grant universities (probably in the midwest where e85 is more common) the same off the production line FFV.  Give them specific parameters and see who can get the best e85 mileage off the same vehicle...

 

I think that this would be a much wiser use of GEs money then the millions spent lobbying congress for e15.  Get FFVs to have better mileage so more of them will use e85 ;D

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Could not a dedicated e85 only engine be tuned to burn leaner, increasing mileage and NOT burn too hot or emit too much NOx?

 

Could they not simply adjust the computer tuning peramiters to run leaner  on e85 then on gas?  Or do they already do this?

 

I still think that current FFVs could have a LOT more tuning done to them to increase e85 mileage and lessen, if not remove the ethanol penalty for efficiency compared to gas.

 

 

 

  I would think "lean burn" could be employed during light load conditions: 

 

    cruising down the highway at moderate speeds ( <70 mph) 

 

    downhill for extended lengths of time

 

    city driving, as long as it's not too much stop-n-go.

 

  Don't know if they already have a strategy like this going, but with cooler burning E85

I'd expect NoX wouldn't be as much of an issue.

 

  It should be similar to how a cylinder or two is disabled during light-load conditions.

 

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The other guy in South Carolina who modifies QuadraJet carbs for ethanol has his set up for a lean cruise. I dont think there are any emissions testing stations in SC where he could find out if it is indeed increasing NOX. It would be something to look into. I have been told that higher compression increases NOX as well, but those people were speaking about gasoline engines, I would be interested in finding out if my high compression 455 produces more or less NOX, and at what lambda. Unfortunately, there are no testing stations here either.

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I've wondered if there were any "tuning" adjustments to my car that could be programed in that would adjust it to be "more optimized" for e85?  You see the SCT tuners and others on the market that can load custom tunes on cars...

 

Is there any sort of file sharing where others that have tuned for these same things could share their results... otherwise you have people independently re-inventing the wheel.

 

A sort of "open source network for custom tunes"...

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Tuning adjustments?  Trying opening the e-85 add on kit and making adjustments.  I would not do this without a scanguage II or comparable hardware that can provide visual feedback on fuel trim values, mpg figures and what ever else needs to be monitored.

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Engimuneer tells me it's probably not going to work on newer engines. He's had trouble getting it to work for more than a few minutes, then the trim adjusts for it.

 

I found that lean burn on my Volt just caused the ICE to run faster when I tested it at speeds < 40 mph.

 

So you may be able to get it to work with vehicles about the same year as the link below.

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If you're running a lean burn by turning off the closed loop function (lower O2 sensor Rich/Lean switchover amperage) and always running open loop, then you can run lean burn IF you are sticking with a single fuel with known stoichiometry. Since E85 is commonly E70-E85, and one might have to fill up with regular gasoline on occasion. Lean burn quickly becomes possible detonation with the wrong timing. You'd also be stuck with running a single timing table that was optimized for a slightly richer burn, where lean burn requires additional advancement in timing.

 

I'd also be concerned with catalytic converters clogging with running lean burn too often. The reason we run 5% rich, is to feed the catalyst and maintain 3000 degrees. By running lower temp and lean burn, we increase NOx and allow any carbon/soot/particulate matter to start filling up the fine mesh. I have ZERO research that indicates this happens nor have I read any white papers indicating that is the concern with vehicles. It certainly is with generators we use in the oil fields.

 

I'm in the same boat as other Volt owners, I just don't use enough fuel to do decent testing in a timely manner. I've run 4 tanks total through my 2013, all E50-E80. Even with my settings for E55, I got the P0171 lean code on E80. As I improve the tune, I will release my findings. Working with TD, I should be able to get some good numbers and iterations that improve the already epic Volt.

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I'm in the same boat as other Volt owners, I just don't use enough fuel to do decent testing in a timely manner. I've run 4 tanks total through my 2013, all E50-E80. Even with my settings for E55, I got the P0171 lean code on E80. As I improve the tune, I will release my findings. Working with TD, I should be able to get some good numbers and iterations that improve the already epic Volt.

 

Thanks. I look forward to that. I usually drive to my home town, about 100 miles round trip, every 3 or so weeks. I'd love to do it in a Bolt and the free electricity I get from my apartment complex, but cheap E85 is almost as good.

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FWIW, we've accomplished lean burn on the first generation Chevy Volt, but if you're going to do this with any alcohol blend where you don't know exactly what % of ethanol you have, you'll have to install an alcohol sensor. Why? Because the only way to go lean was to use open loop (oxygen sensor disabled).

 

To complicate things even more, you don't want to go lean until engine coolant hits a certain temperature (we chose lean starting at 154°F and full lean at 176°F and above). Also, due to the loss of power when lean, we had to increase cam overlap to increase power, especially at 1400 where we went the most lean and of course that means we needed a LOT more spark advance (10 to 18° more) at these lower rpm. But we had to subtract spark at the cold coolant temps (below 176°F) where we haven't gone lean yet. This was not an easy tune.

 

Due to the load of the motor generator, first gen Volts idle at 1400 and at 70 mph, under good conditions will hit 2000 to 2200 rpm. So we went as low as 20:1 lean (E10, 91 octane) at 1400 rpm, tapering off to slightly lean at 2200 and normal above that due to increasing engine load. This worked so well, I managed to go 60 mph at 1400 rpm continuous for about 20 minutes, after which I grew bored.

 

Once we had everything set up with 91 octane premium, we continued to test with higher blends of ethanol and again had no problems with lean cruise with e85.

 

Heat isn't a problem when you go this lean and driveability wasn't an issue either. It drove as good or better than stock even at 20:1.

 

You can read more about our tune here: https://forum.hptuners.com/showthread.php?63020-First-Gen-Volt-Tune-(Volterado) 

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