[blkscooby]

E85 seems to be just gaining popularity among the NA crowd. I had run it in my modded 08 STI with great results.

My searching here only turned up 2 guys with any experience with it, one being boosted.

So this past week I filled up the tank, tuned it, and went to the track on Fri night. results here- http://www.g8board.com/forums/showthread.php?p=650058&posted=1#post650058

I would like this thread to be a discussion of the results and questions regarding the performance gains, not a political discussion. Hey its $2.65/ gal 105 octane race gas with added cylinder cooling properties of alcohol. What's not to love?

BTW, our 42 lb/hr injectors can handle the 30% extra fuel probably even up to LT and full exhaust setups. Just need to tune.

 

[J Wikoff]

Do you have a tuned time on regular gas to compare?

 

[blkscooby]

Do you have a tuned time on regular gas to compare?

Not at the track. I pulled a 13.7 @ 102 from my Cortex before I switched over to HPT but that was done on the street.

 

[JSGT09]

But we can't run E85 full time though because our lines, pumps, etc aren't designed for it, correct?

 

[J Wikoff]

That's kind of unknown if they are compatible or not.

 

[bluegoat06]

That's the only thing that keeps me away from pure E85, not knowing if the fuel lines/pump are up to the task of supporting E85 full time. BTW Scobby, i haven't have enough time to give you the congrats, but i'ts very good to see how much you have accomplished in little time :thumbsup:

I'm waiting to have my Rotofab in the mail today, then install it on Saturday and re-tune for it. once that's done,i'll look into blending E85 with the E10 91 octane gas we get here in Southern Cali, and do a tune with it.

According to a little spreadsheet i did, 4 gallons of E85 combined with 14 gallons of 91 octane E10 should put me around E25, and bump the octane to 94.

For what i've been reading, we can get the ethanol anti knock properties above E20, so E25 (in fact it would 26.66% ethanol) should be ok while still having less concentration of ethanol that can corrode lines/fuel pump etc.

The new afr stoich would be around 13.16, right now i'm running 14.45 since our gas may contain 10% ethanol, so i'll just set stoich afr at 13.20 and retune my MAF in CL.

 

[bluegoat06]

Here is the excel spreadsheet, i had to rename the extension (i'm using office 2007) from .xlsx to .xls so the file type and size, would be in compliance with our forum.

If you have Office 2007 and above, excel would convert the file once you open it, you would get an error that says the file type doesn't match, but once you click yes, open anyways, excel would convert the file and open it.

It's very basic, so don't expect beauty,tons of alerts or error proof , you just type the number of gallons and octane of the gas, and it would spit the aprox ethanol content in the blend,octane and stoich afr.

 

[blkscooby]

Bluegoat, your blend calcs are right on. I used to use this website tool- http://www.bazellracefuels.com/Calcs/OC1.htm

And I wouldn't be too worried about the fuel system. Like I said, I ran E85 in my Subaru for 6 months and many people have it for 4-5 years. Ethanol is not corrosive like methanol is. The biggest issue is that it is hydroscopic, meaning it absorbs water. I would not store a vehicle for any length of time with E85 in it.

 

[bluegoat06]

I found a gas station that sells E85 15 min away from where i work according to googlemaps. i'll give it a try soon

Are you running E85 now full time ?

 

[iisme13]

Ok so let me get this straight. We can run e85 stock? All I would have to do is tune?

 

[blkscooby]

I found a gas station that sells E85 15 min away from where i work according to googlemaps. i'll give it a try soon

Are you running E85 now full time ?

No, but only because I have to go out of my way to get it. But I will run it at the track instead of 91.

 

[blkscooby]

Ok so let me get this straight. We can run e85 stock? All I would have to do is tune?

Pretty much. The only potential issue I can see is the fuel pump. I'm not sure if its the same as in a flex fuel vehicle. But even if its not, I highly doubt that we will see failures.

I used a regular Walbro pump in my Subaru STI and the only reason I changed it from the stock one is that I needed higher flow for the larger injectors I installed (I added a larger turbo when I switched to E85).

 

[blkscooby]

So my guess on gains on my car (mods in sig) is 4* advance over 91 oct, probably 20-30 HP. I estimate I gained 0.3-0.4 s and 2-3 MPH in the 1/4. I had not run the car using 91 at the track but I did on the street with the Cortex (13.7 @ 102.5) vs (13.2 @ 106.5). I know my 91 times would have been better on the track.

 

[iisme13]

So would you say upgrade fuel pump to a walboro

 

[bostonf4$]

my car's already tuned for 93 octane, what would happen if I put E85 in w/ that tune?

 

[jatrex17]

my car's already tuned for 93 octane, what would happen if I put E85 in w/ that tune?

Bad idea.

 

[richm52]

Ok so let me get this straight. We can run e85 stock? All I would have to do is tune?

Can you run E85, on occassion, without a tune?

 

[Roddy]

Interesting stuff here guys! I'm going to keep following. Maybe i'll try this sometime.

 

[blkscooby]

Can you run E85, on occasion, without a tune?

No, absolutely not. E85 requires 30% more fuel than standard E10 pump gas, regardless of the octane. Wihtout a tune the car would run extremely lean, even in CL as the PCM cannot add 30% fuel (I think max is 25%).

What flex fuel vehicles have that we do not is an ethanol sensor that measures the ethanol content and adjusts the CL fuel target accordingly. We do have the lookup table for this CL fuel target but no sensor.

So we have to tune for E85. Its not hard as I have determined but you have to tune for it, even for a 25% blend to raise 91 oct to 94 oct which BlueGoat is investigating.

 

[richm52]

Thanks...you explaination cleared up a lot of questions. Thanks