A little mixing experiment

[sonicboost14]

So......I mixed in e85

Before the doomsayers come out screaming "you'll burn up your engine", hear me out. I've owned a ton of cars and done some boneheaded things but all with research before hand.
There is only 1 e85 station within 25 miles and its still a hike so I thought I'd give it a go. I waited till I was down to 1/4 tank of 93 and filled it to the brim with corn.
Wow.
I'm budget tuned with a header wrapped and coated SRI so nothing extreme. I use the TorquePro app on a tablet and have been watching boost numbers since the tune. Before I powdercoated and wrapped the intake, at 85 degrees ambient temp I was running 19-20psi and dying off after 5k rpm. The IAT temps were 30+ degrees hotter. After wrap and coating, I'm peaking at 21psi and 10-15 degrees up from outside temp.
On the e85 mix (more like e47) I'm regularly running 23-24psi and it pulls had and fast to 6k rpms. No detonation or overtemp. Just a sweet, sickening smell from the exhaust. I'm a quarter of a tank gone and the mileage has slumped from 32-35mpg to 26mpg but hey, it hauls!

Just my experience. Yours might vary.

 

[River_Rat]

Please do keep us posted on how this works out for you. opcorn:

 

[sonicboost14]

I'm sure it will be fine. I'm 10miles from the gas station so its not plausible to get the e85 tune with all the $ that goes with it. Just a nice $2.65gal goof about.

 

[River_Rat]

Since you have the Torque app, why don't you take a look at your Long Term Fuel Trim and see where it reads?

 

[SonicBRO]

Have you read any threads about fuel mixtures with out adjusting tunes? Id be skeptable about timing issues and gasket failure.

 

[sonicboost14]

I was worried about the ECU keeping up or over doing it with the timing. Just hoped the car would "self protect" if it leaned out. Not worried. Or stupid. Whichever.
I figured the "intelligent" octane tune will compensate for most of it. The Sonic and Cruze, from what I've read, are ethanol compatible but GM didn't unlock the maps for it. One tank won't kill the gaskets. The 93/e85 mixture brings the octane up to 100ish so the tune should work with it. The only bad reaction I've seen is it falls on its face in the mornings (55-60degrees) till I get a few miles down the road.
I haven't been able to figure out the "data logging" on TorquePro so I lose the info everytime it shuts off.
I'm old and don't rocket around everywhere. 36yrs old but feel every bit of 50. So romping on it at all times is a no no.

 

[Stew]

I've ran across forums where people run a mix of E85 on cars that are not flexfuel and the ECU can compensate for the different fuel pretty good. Wherever I was reading that someone had taken a pic of the gas pump and it had several different ethanol mixes you could pick from, E10, E20, E40, etc. I've actually though about running a tank of 1/2 E85 and 1/2 regular fuel to see if I could tell a difference.

Certainly if you were going to run E85 all the time it would be advantageous to adjust your tune for it instead of relying on fuel trims, plus you can dial in more timing.

Good post though!

 

[NewZJ]

Stew, if you can find an e85 station in the pnw you are a better searcher than I. I'm so interested in ramping up my octane I've bought a water/meth kit (not yet installed)

 

[overwest]

Stew, if you can find an e85 station in the pnw you are a better searcher than I. I'm so interested in ramping up my octane I've bought a water/meth kit (not yet installed)

I feel your pain fellow Washingtonians haha. When the family purchased a new 07' Tahoe I remember the dealership specifically talking up the FlexFuel, and you look around and there's about nothing in terms of pumps that offer it. First time I remember looking at the map it said the only one close by was on a military base.

 

[Swordsmith]

There are no gaskets or anything that should cause trouble, the engine was designed to run E85 straight, has the tables in the ECU for it and everything, it just doesn't have an alcohol sensor to tell it what you're feeding it. The sole "not designed for E85 component" we could find is the segment of fuel line between the firewall and the injectors. As you say, it is unlikely occasionally running some E85 will damage that, but if you wanted to be belt and suspenders safe, you could replace that line cheaply and easily.

The physical component for E85 conversion are bigger fuel injectors; E85 has a lower energy density, so to make the same power requires more fuel... and to make more power, which it allows, requires even more fuel, but at a certain point the stock injectors go static and cannot deliver any more.

The third possible component would be an alcohol sensor. That goes on that same fuel line I was talking about, and is wired to the ECU so now it can tell what your current fuel mix is and adjust accordingly.

I am very surprised to hear you are getting good results on E47 without a tune designed for it, and without a sensor to tell your ECU what is up. I guess the same system it uses to run 93/91/87 is at play, it starts out running highly advanced timing and then retards until no knock. So it "thinks" you are running 100 octane gas and doesn't care that the gas is really half corn.

The other weird result is that you are seeing higher boost; I get the reverse on corn, my boost is actually lower. What are you seeing for hp and torque figures? I know your butt dyno tells you you are getting more on the E47, but what about the app?

 

[sonicboost14]

I threw the TorquePro app on this morning on my way into work. 24psi peak, long term fuel trim was +18.32%, mpg was 24.7, and timing was 9 advanced. Not terrible.
All logic says more torque on the actual engine and lower psi due to less need for boost. Dunno.

 

[sonicboost14]

And also:
I found the station I used by using a website that locates e85 stations near you. Google it or look on the app store of you choice. Sure something's there.

 

[Stew]

Stew, if you can find an e85 station in the pnw you are a better searcher than I. I'm so interested in ramping up my octane I've bought a water/meth kit (not yet installed)

A couple years ago they built a new Shell gas station about a mile away from my house that has E85. It's the only one around that I've seen, and it's interesting that they built it where they did - in the Smokey Point area, because this isn't exactly a densely populated area and it's far enough off the freeway exit that freeway travelers looking for gas won't see it.

Next time you're up this way you'll have to check it out, heading north on I-5 take the Smokey Point exit, hang a left at the end of the off ramp and go west for a mile or so and it's on the right!

 

[Sneakerfix]

what year is your sonic? you can mix e85 with gas but at some point youll get a lean code. why not do the e85 conversion without using the bigger injectors

 

[sonicboost14]

Me?

Mine is a '14 1.4t 6m hatch

I've been flogging it the past few days and its running good. The car is only 3mths old/2300miles. I live too far from an e85 station to justify the tune and the cost. I have the one station and its 10ish miles away. I did it to see what it'd do.

 

[Sneakerfix]

You don't need to use bigger injectors to run e85 on the 12+ cruzes and sonics. You just need the flexfuel sensor and tune which will let you use both

 

[Stew]

You don't need to use bigger injectors to run e85 on the 12+ cruzes and sonics. You just need the flexfuel sensor and tune which will let you use both

True, IF you are only going to tune it to utilize the flexfuel sensor and aren't going to increase power levels. If you are also going to increase power levels you need to upgrade to the 42 lb injectors, the OEM injectors simply cannot flow enough fuel for an E85 tune with higher than OEM airflow (boost). Heck, they barely flow enough for a standard non-E85 tune.

 

[sonicboost14]

Update:

After running the tank out, I've got some observations.
1 It ran like a raped ape. Pulled like a different car throughout the RPM range.
2 Ran a little lean but not terrible. I threw a code at about 1/8 tank but it was only on a 90degree day and running the hell out of it.

Now the bad observations:
1 Little hard to start on cold mornings
2 REALLY reduced power in the mornings till the car warmed up

Now the weirdest:
The Trifecta budget tune is supposed to adjust for octane levels. I guess anything over 93 freaks it out. I'm halfway thru a tank of 93 and its only getting 25mpg and it stumbles a bit once in a while. Its like it adjusted for the e85/93 mix and got stuck there. I flashed the tune again and its all back to normal.

So there you go.

 

[cndctrdj]

Interesting to see this. I keep thinking about that sensor that tells the car what is running. But then I think I would love the injectors and then I think. It a my daily and don't need to mess with it

 

[PocketRocket]

Does anyone use 100 octane on stock tune and stock parts? I've been wondering if I should give it a try. Maybe do half tank of 100 and half tank of 91 and see if there's any issues. I do have an injen intake which I'm debating of just returning my car to stock intake. All the intake did was make a ***y woosh noise. If anyone has used 100 octane and lived to tell about it please share your experiences. I'm never going to tune my car. There are too many headaches associated with a tune. Tell us how it ran and if it felt abnormal. Thanks. 100 octane is everywhere in las Vegas so **** it let's give it a try