Tuning for E85

[factorb]

Hey guys have a couple questions? Diablosport has a tuner out that lets 99 and up trucks run on e85 without changing anything. Can you get a custom dual tune that would be e85 on your high octane table and 91 or 89 on the low octane so you could run both? E85 in Nebraska is about $2.20 a gallon and regular is $2.79 so it is cheaper even if I lose some milage. Thanks.

[Tank]

your fuel system won't do it though unless you mod (i believe anyways)

[fubutx]

I do know u can change the parameters around making custom, but not sure if you can change parameters depending on the octane you use, since its meant for e85.

I know with the regular diablosport u can change it depending on octane you use.

I would say I would get with the guys over at diablosport to get a forsure answer.

[factorb]

The diablo tuner says that it will let you run any kind of ethanol from e5 to e85 with their tuner. I was just wondering if someone like nelson or blackbear could dual tune a pcm to do both? I would rather have a custom tune from one of them than spend $400 on a diablosport.

[metalchips]

I would check if you would need larger injectors to run the E85, that is how they come set up stock for E85.

E85 = more fuel used

[truckinL33]

E85 requires 30-40% more fuel to do the same as E10 (regular gas). You will need larger injectors, and fuel pump. Also, E85's stoich. is at about 8.5:1 where E10 is at 14.7:1. You will need a tune to run E85, and on top of it the fuel is not regulated by the government like E10 is. This means that depending what gas station you go to, the ethenol content will vary i.e. it may be E80 at one station E82 at another and so on. Winter blend is closer to E70 and E75. For the most consistant results, you'll want to go to the same station to fill up all the time, and you'll want to test the fuel before hand to know what the exact mixture is. There are testing kits you can buy at an inexpensive price. Also, there is an additive lubricant you can get from just about any parts store that you will want to add to the fuel tank evey other fill up, so that you don't dry out all the rubber in your fuel system. When you tune, do not tune with a regular air/fuel calibration. Instead, you're going to have to tune on lamda. 1.0 is stoich for E85, and it's also stoich. for E10. Tune with this value, instead of AFR unless the tuner has it calibrated for E85. The lamda value is going to have to be around .73 for a proper AFR, it compares to having an E10 AFR at about 12.5:1. It sounds rediculous, I know. In reality, it's not hard at all to keep up with. I would def. recommend getting an AEM E85 wideband to monitor the AFR. This gauge is calibrated for E85, and it ranges from 5.9 to 11.5. Any more questions, feel free to ask.

[truckinL33]

I almost forgot, you're gonna need to run a fuel filter that is compatible with E85. The E10 paper filter will get rocked quickley from the corrosive nature of ethonol.

[Chevy366]

Go to EFILive's site , a guy over there , a GM Tech , devised a device 5v sign wave you can hook into the PCM and dial in the E-content on the fly (varying voltage) and it uses the PCM parameters (if there , must have flex fuel PCM OS) for flex fuel , which does some timing , injector and few other segments in the PCM that are needed and no it is not the expensive GM module they sell , just a very simple easy to make device .

[factorb]

Thanks guys for all the reply's. I was just wanting some more info on this to clear up some questions I had. Diablosport makes it sound like all you need is to buy their tuner to run e85. I knew it sounded too good to be true but they don't tell you that.

[Chevy366]

Just to clarify , you can run E85 without harm , the only thing is E85 will tend to act as a cleaner , so it might clog the filter at first , but yes just tune and go.

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