School me on swapping from 91 to E85

r3meyer

r3meyer

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Friend picked up a car that runs on E85 and has for a long time so I am just looking into this.  Turns out I have an E85 station down from me that I did not know about, but I guess it's a popular spot  because of this.  Im curious what kind of power can be made switching to 91 from E85.  I have always just wanted a safe 91 tune, but maybe I should consider making the swap if the power gain is consierable.

In the very little research I have done I see that Holley (AEM) makes an inline fuel sensor that my Holley HP dash can display the ethanol content % right on my screen.  Im sure Holley probably has a tuning chart to compensate for lower grade fuel should it get some to keep the engine happy and will adjust timing based on its readings from this sensor also.

Anyone made the swap and regret it?  Edit: I am currently boosted with 6-8lbs from my whipple.

 
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I run flex fuel essentially. So not pure e85. I picked up 20whp on 40% ethanol. That’s n/a. I use Holley as well. For me it cost me an extra 150$ to put the flex fuel sensor in. Everything else as far as fuel system was set up for ethanol as I was planning on throwing boost at it in the future. 

 
I think I am going to do it soon.   if you are boosted then it is the way to go.  drops intake temps you can add more timing etc.  boosted can add easy 100hp.  On a Na motor figure about a 10 to 15% gain.  Run much cooler but also use about 30% more fuel.  If you have a Holley HP like I do then we need, if boosted bigger injectors and a flex fuel sensor.  Using the flex fuel sensor you can run any percent of E85.  So you can mix 50/50 if you want and the ecu adjust for the amount of E is mixed in.  I am planning on running 50/50 so I don't go though so much fuel and i can stretch it out per trip but keep the cooling properties of the fuel for intake temps. Last trip I burned 180 gallons of fuel so adding 30% could be a storage issue. 

 
I switched mine from race fuel to E85,  in the off season. I don't run a sensor because the station I get the E85 from has a least a 85 blend. All the people with fixed up cars go to this station. My car run 20psi boost. I switched all the fuel line to PTFE and added a holly matt to the tank. Had to go to bigger injectors and added a another pump for the amount of fuel needed. Just calculate the hp you want and work your way back. Car never get s warm and runs awesome.

 
I went E85 instead of race gas and never looked back. You will absolutely need bigger injectors, I went from 550CC to 1KCC. I do have a flex fuel sensor installed but never actually had it connected or ever tuned for it. My local station has always been 85-95% ethanol. I love the cost as well. I think I paid $2.89 per gallon. My only dislike is the amount of condensation on startup. 

 
I’d stay on the corn if at all possible. The safety factor and power gain are faaaaaaaaaaar superior to 91 owl piss. I don’t even trust straight 91 on my factory boosted 4-banger. 

Flex fuel sensor and mix if it’s super annoying, but I wouldn’t ever go back to 91 boosted if I can help it. 

 
r3meyer said:
Friend picked up a car that runs on E85 and has for a long time so I am just looking into this.  Turns out I have an E85 station down from me that I did not know about, but I guess it's a popular spot  because of this.  Im curious what kind of power can be made switching to 91 from E85.  I have always just wanted a safe 91 tune, but maybe I should consider making the swap if the power gain is consierable.

In the very little research I have done I see that Holley (AEM) makes an inline fuel sensor that my Holley HP dash can display the ethanol content % right on my screen.  Im sure Holley probably has a tuning chart to compensate for lower grade fuel should it get some to keep the engine happy and will adjust timing based on its readings from this sensor also.

Anyone made the swap and regret it?  Edit: I am currently boosted with 6-8lbs from my whipple.
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The E85 will really bring the motor to life. I have never been in a 91 motor that was impressive at all. Especially a blower motor. They are kinda slow in the first place but on good gas they can be fun. The car will run cooler but you need to do your maintenance. Filters every season, make sure your lines are E85 rated so you don’t have one crack and burn your car to the ground. I also recommend changing your oil after every trip or two weeks of riding. Tuners use so much fuel in the tunes that it’s going to get passed the rings. Also, just get used to the extra blow by. 

 
As all others have stated bigger injectors, burns more fuel, PTFE lines a must as the ethanol will eat just regular fuel line.  E85 is a cold hearted bish, with a proper tune and assume you have o2 sensors I believe that will help with the cold starts.  Lower intake temp, big boost and easier on the pocket.   I will say you have to be somewhat on point with e85.  If you store your car in the summer months I highly recommend draining the e85 and throwing some 91 in and cycle the car as the e85 will turn into gel.  I took last season off and was lazy and didn't drain the e85, resulted in having to completely redo my entire fuel system including injectors  During the season I/we use a ethanol stabilizer that @Grease Monkey is a distributor for,  Rev-X ethanol stabilizer.  Ive also noticed the oil life isn't what it used to be, being bigger injectors are dumping so much more fuel.  You can literally drain your oil let it sit over night and you will see the e85 rise to the top, so more oil changes but you save that at the pump.  I'm just a lil subaru guy but believe everything applies no matter the motor.

 
I switched my stroker LS2 with Magnacharger at 6psi from 91 to E85 three seasons ago. Upgraded to PTFE fuel lines, larger Areomotive Dominator pump, bigger injectors, microglass 10 fuel filter element. Redline tuned making 659hp at the tires. Very happy with it and everyone in our dune group is on e85 which is convenient. My son's new to him Tatum Sand Demon has a @John@Outfront turbo Subi on e85 as well.

 There's a 76 station a mile from my house and in 3 years it's always tested at E90 or better.

 
Thermostat is also a must.  If your car never gets to operating temperature (180*F+), you're going to turn the oil into mush.

 
L.R.S. said:
I switched my stroker LS2 with Magnacharger at 6psi from 91 to E85 three seasons ago. Upgraded to PTFE fuel lines, larger Areomotive Dominator pump, bigger injectors, microglass 10 fuel filter element. Redline tuned making 659hp at the tires. Very happy with it and everyone in our dune group is on e85 which is convenient. My son's new to him Tatum Sand Demon has a @John@Outfront turbo Subi on e85 as well.

 There's a 76 station a mile from my house and in 3 years it's always tested at E90 or better.
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What are you running for boost after the swap?  Do you know what you picked up power wise?

The station that is by me is a 76, so thats the only reason I am considering this.  AZ does not have many E85 stations that I know of.  Curious if there are any coming from PHX to Glamis that anyone knows up taking the I-10 and the 78?

 
Rockwood said:
Thermostat is also a must.  If your car never gets to operating temperature (180*F+), you're going to turn the oil into mush.
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I run a thermostat.  My radiator is huge and at this time I dont have a windshield.  

 
I fill up e85 at the 76 on 91st and olive tests e80-e85.

the chevron on 67th and McDowell tests e85-e90. 

 
r3meyer said:
What are you running for boost after the swap?  Do you know what you picked up power wise?

The station that is by me is a 76, so thats the only reason I am considering this.  AZ does not have many E85 stations that I know of.  Curious if there are any coming from PHX to Glamis that anyone knows up taking the I-10 and the 78?
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I make 5-6psi before and after.  It really helped with engine temps.  Not sure what I gained but most engine builders I talk to have all said they see 100hp gains on big boostged engines when swapped to E85.

Get a $20 test kit, takes a couple minutes.  E85 isn't as bad as people think.  I'll save my E85 in a drum all summer and run it again the next season if it tests good.  You will need to increase maintenance on engine oil/filter and fuel filters.  Danzio and Redline reccomend engine oil/filter after each trip, especially on big boosted cars.  

 
L.R.S. said:
...E85 in a drum all summer and run it again the next season if it tests good...
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E85, being mostly alcohol is extremely hygroscopic and that is the biggest issue with E85 and longevity.  If your fuel system and/or fuel storage aren't fully sealed E85 with absorb a ton of moisture and at that point it's junk.  On that note, storing with a full tank/full drum etc. for as little air-space as possible is also best.  

Depending on who you ask, E85 is something like 100-105 octane, but most tuners will say it makes as much power as 110-114 gasoline.  The big thing for me when it comes to E85, as @Rockwood pointed out, the safety factor is huge.  The tuning window is just so much bigger, it's almost hard to get an E85 engine to detonate.  You will take a MPG hit, not that most of us care about MPG as a number, but if you happen to have a small fuel tank/cell in your rig it's a consideration.  E85 carries about 30% less energy by volume, so in theory you should use about 30% more.  However, it's not that black and white.  First, for cruise you can be much more aggressive with timing which generally improves Brake Specific Fuel Consumption (aka efficiency) so maybe you can make up a little of that 30% loss.  However, at WOT you might find you're using more than 30% more... but that's because you are making more power than you did on straight gasoline so you're taking the 30% energy hit *plus* using more fuel to make that extra power.  

-TJ

 
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