Tuning for E85

[GnatGoSplat]

A local gas station just opened an E85 pump in town. Right now it's only about 5% cheaper, but everything I've read has led me to believe a properly tuned turbocharged engine will lose around 5% fuel economy but gain up to 10% performance increase on E85. If that's true, then the end result is the operating costs will be the same, performance will be better, and there are always good political/environmental reasons to use E85.

 

Has anyone tried E85 in a TGP? Anyone currently tuning for it?

 

I realize some parts aren't E85-friendly, but I don't think the potential long-term problems occur immediately nor are they catastrophic.

 

[z284pwr]

I have actually thought about doing it and installing lines that are alcohol friendly then taking the car to Colorado and having Kenny attempt to tune a chip for E85 and one for just regular gas and just have 2 chips they are easy enough to change.....E85 just isn't widely available enough yet to consider it and considering it was tons more expensive around here since they are dumb and won't bump production

[TGPilot]

I ran E85 in the 5-speed TGP for about 1 week. The injectors that are stock are WAY too small. The injectors in the car now/then are Ford Racing (flowing about 23-24.5lbs/hour). They were MAXED and I was still +3 points away from "safe" fuel under 1Bar of boost. The A/F for Alcohol is down to 6.45 - 6.5:1 for N/A applications but right near 5.0 - 5.3:1 for a proper mix under boost. In order to get that mixture we nearly need to DOUBLE (between 1/3rd larger and double) the injector size to allow for a 0.02ms window for the intake valve to be open and at 89% duty cycle.

 

Now the consumption issues begin to boggle my mind. If we are using nearly twice as much flow why don't we use twice as much fuel? I have not gotten that far yet to tune for MAX economy (extremely lean) when not in boost and then put the Alcohol to her when she is in boost and stay safe. Maybe in Spring when the high boost motor is built and put in the shop car?

[z284pwr]

Now the consumption issues begin to boggle my mind. If we are using nearly twice as much flow why don't we use twice as much fuel? I have not gotten that far yet to tune for MAX economy (extremely lean) when not in boost and then put the Alcohol to her when she is in boost and stay safe. Maybe in Spring when the high boost motor is built and put in the shop car?

 

I know true methanol burns twice as fast, hence why Sprint Cars cant race nearly as long without a pit stop as other gasoline engines.

[GutlessSupreme]

Now the consumption issues begin to boggle my mind. If we are using nearly twice as much flow why don't we use twice as much fuel?

 

E85 is "thicker" than regular gasoline. It's not actually flowing x2 volume. Simple explaination but I believe it makes sense enough lol.

[TGPilot]

Say what?

 

Where is your information about viscocity between gas and Alcohol? Links? Book?

[GutlessSupreme]

Say what?

 

Where is your information about viscocity between gas and Alcohol? Links? Book?

 

I couldn't cite one off hand, but I did do a report on alternative energy sources last semester that involved ethanol. I'll see what I can dig up. I may be mistaken, but I believe that was the reason for needing things such as bigger injectors.

[mfewtrail]

Now the consumption issues begin to boggle my mind. If we are using nearly twice as much flow why don't we use twice as much fuel?

 

Kenny, you are using more fuel if you're flowing twice as much compared to normal. Ethanol contains less energy(I've seen figures saying approximately 30% less) than gasoline, so more of it is required.

EDIT: Adding a quote from a excerpt on E85,

 

"E85 has an octane rating of 105, which is higher than typical commercial gasoline mixtures (octane ratings of 85 to 98); however, it does not burn as efficiently in traditionally-manufactured internal-combustion engines. Additionally, E85 contains less energy per volume as compared to gasoline. Although E85 contains only 72% of the energy on a gallon-for-gallon basis compared to gasoline, experimenters have seen slightly better fuel mileage than the 28% this difference in energy content implies. For example, recent tests by the National Renewable Energy Lab on fleet vehicles owned by the state of Ohio showed about a 25% reduction in mpg [1] (see table on pg 5) comparing E85 operation to reformulated gasoline in the same flexible fuel vehicle. Results compared against a gasoline-only vehicle were essentially the same, about a 25% reduction in volumetric fuel economy with E85."