E85 Tune

[turbo]

Forgive me if any of these questions have already been definitively answered...

I recently discovered that I can get cheap E85 in my area...and I'm considering requesting a special E85 tune. I have the following questions...

1.) With an E-85 tune, are bigger injectors absolutely mandatory?
2) Will the bigger injectors kill fuel economy or mess with anything when I'm not running my E-85 tune?
3.) Does running E-85 hurt fuel economy?
4.) What kind of power gains can I expect going from a premium tune for 91 octane to an E-85 tune?

 

[Eric Smit]

Yes.
Possibly.
Yes.
Big.


-Eric Smit

 

[laborsmith]

The questions should be directed to the tuner of your choice. I will attempt to answer based on what I have read and a conversation on this I had with David Michel several months ago.

It is my understanding the the 1.4T is a flex fuel engine which would indicate larger injectors are not absolutely necessary but beneficial to get the most from e-85.

There is a huge difference between 91 and e-85 fuel economy. Based on my memory when I used e-85 in my Silverado one summer almost 30% difference. I would think larger injectors would not help.

There is a significant power gain, especially using the 43lb injectors, but even staying with the OEM 29lb injectors. Vince Geglia has posted improvements. He has a FB page (Trifecta Performance) and also is at WOT. I would recommend visiting both if you are interested.

Labormith

 

[d.p]

1.) With an E-85 tune, are bigger injectors absolutely mandatory?
YOU SHOULD

2) Will the bigger injectors kill fuel economy or mess with anything when I'm not running my E-85 tune?
PROBLEM WITH THIS IS COMPLETELY CHANGING FUEL, YOU SHOULDN'T MIX THEM.

3.) Does running E-85 hurt fuel economy?
YES, VERY MUCH SO.

4.) What kind of power gains can I expect going from a premium tune for 91 octane to an E-85 tune?
WITH BIGGER INJECTORS, E85, AND A TUNE I GUESSTIMATE YOU'LL BE IN THE 260-270 RANGE DEPENDING ON HOW BIG OF INJECTORS YOU USE, THE TUNE YOU GET, AND THE QUALITY OF YOUR ALGAE JUICE.

 

[MrSonic]

260 - 270HP or WHP????????

 

[turbo]

WITH BIGGER INJECTORS, E85, AND A TUNE I GUESSTIMATE YOU'LL BE IN THE 260-270 RANGE DEPENDING ON HOW BIG OF INJECTORS YOU USE, THE TUNE YOU GET, AND THE QUALITY OF YOUR ALGAE JUICE.

WOW...

 

[sonic hotness]

I thought I saw numbers around
190hp 240tq with bigger injectors

 

[d.p]

that was tq**

 

[sx sonic]

Te other members have poseted some very good stuff. As for bigger injectors with regular gas, so long as you don't go too big or radical on the engine everything should work fine on either fuel.

The issue that traditionally happens with going to big injectors is evrything runs fine when your going wide open, the injectors are right in the upper sweet spot of duty cycle, but then at idle when very little fuel is needed they are forced to open for incredibly short amounts of time since they flow so much, when the duty cycle gets to short the fueling becomes unpredictable and metering the fuel accutrately becomes difficult.

With smaller injectors they are able to stay open longer providing consistent and accurate fueling at idle, but then they run out of flow capacity/max duty cycle if a lot of fuel is required...

The reason injectors need X amount of time to be open to provide accurate fueling is that the flow is not linear as the injector opens, it takes a brief second after the injector opens for the flow to become linear. (An exaggeration would be you get 2lbs.of fuel in .5sec at open, then 5lbs after 1sec and from that point on its 10lbs fuel every second). There is a name for this condition but idr of the top of my h ead.
In some high output cars, usually forced induction engines with a huge thirst for fuel at WOT and an effiecient idle 2 injectors are used per cylinder just for this reason.
Message vince to be certain but I don't think the bigger injectors having givin anyone issues yet with lower octane fuel

 

[rodslinger]

Take a look at the E85 conversion for a Cruze. Sonic should be similar. In short they added the fuel type sensor at the fuel rail, replaced injectors and enabled the E85 program in the ECU with related ODB fault codes.

Chev/Holden 1.4L Cruze E85 FlexFuel Conversion

Was looking at this over the weekend actually. Was wondering if I could go in via EFILive and enable this on top of the Trifecta tune or if Trifecta could offer this feature enabled and we would only have to swap injectors and add the sensor.

 

[Maddmatts]

Another alternative to using bigger injectors is to install an extra injector just after the throttlebody and have it controlled by an aftermarket computer and have it add fuel as the oem injectors approach 80% duty cycle.

 

[djfourmoney]

Another alternative to using bigger injectors is to install an extra injector just after the throttlebody and have it controlled by an aftermarket computer and have it add fuel as the oem injectors approach 80% duty cycle.

I would not even suggest this. Its cheap and cheesy, 1980's mallet/blunt solution.

I ran into this same problem with the SRT-4 crowd those living in rural areas and small towns wanting to do cheesy cheap mods for quick power gains.

I've seen close to 100% duty cycle on stock injections on a E85 conversion new model Mustang GT and the tuner said it was fine since duty cycle would only go that high at WOT.

But basic rule of thumb is increased injector flow by 30% for E85.

Just go to somebody that knows what they are doing...

 

[CoHPhasor]

I've seen close to 100% duty cycle on stock injections on a E85 conversion new model Mustang GT and the tuner said it was fine since duty cycle would only go that high at WOT.
.

That person should never tune a vehicle again, ever.
That's the most ridiculous statement I've ever heard, and especially if the vehicle is boosted.

You might as well go buy a new engine ahead of time.
Even a non-boosted engine is getting a severe dis-service by someone like that.
New, larger injectors and proper tune or go home.

 

[Swordsmith]

If you want to swap back and forth between fuels, the best plan is to install a fuel sensor, that way you tune adjusts on the fly and runs off whatever mix you end up with when you add more E85 or 93 to your existing tank. I've run E10, E56, E16, and now E79, all with no problem... other than a slightly low idle and a tendancy to stall at low revs when very cold.

E85 is 105 octane at the pump I'm using. I haven't looked at fuel economy yet, but I expect miles per gallon will be lower. You have to remember, though, that E85 is much cheaper, so your miles per dollar might still be better than with 93. Even if it isn't, it's still greener and most importantly moar powah!

Red pill requires a shiny new clutch. We're just talking about giving the engine a little drink, not forcing it to chug everclear till it comes out it's nose. I mean, for you lesser beings, of course, for me, that red pill is on the way. I wonder how the Sonic feels about grape kool aid mix, that's how we used to drink everclear when I was a youngster.

 

[Eric Smit]

red pill pull.


-Eric Smit

 

[CoHPhasor]

Flexfuel setup installed (first on any sonic, I think?)

Might want to adjust your sig,... Im sure they tested this in their Sonic first.

Idle would suck because the injectors do.
Anytime you're running larger injectors they need to be as closely matched as possible and that just doesn't happen with bargain injectors.
("They're from Bosch, they're not bargain!" - False. They're only tested at a few pulsewidths, not very accurate when you consider the full range)

 

[Eric Smit]

they tested on a Cruze.


-Eric Smit

 

[klystron]

they tested on a Cruze.


-Eric Smit

I saw a thread on hptuners I think where they actually wired in an alcohol sensor and enabled flex fuel. They show how to wire it in and everything. The non-sensor tunes are calculating alcohol consumption probably by looking at how lean the AFR goes on the narrowband.

They did that on a cruze.

 

[Eric Smit]

the non-sensor tunes aren't calculating at all; they just tell the ECU it's E85.


-Eric Smit

 

[Swordsmith]

Might want to adjust your sig,... Im sure they tested this in their Sonic first

There is no "they" here, I bought the sensor from a Buick dealer, along with some wire harness parts, had alcohol ready fuel lines fabricated at a local Hydraulic shop... I didn't buy a kit, although I think BNR is looking into putting a kit together to make it easier.

I'm not making any claims to genius here, I basically copied what they did on the Cruze, had a couple hoses fabricated, found a handy out of the way spot to do the install... but I think I'm right when I say first on a Sonic for a Flexfuel setup. Used the BNR injector kit, but I didn't claim I was the first Sonic with that... I know for a fact Preloader beat me to that, and maybe others.

I know I'm right when I say the first Clutchmasters clutch on a Sonic... again it's a Cruze clutch, I just did the legwork to find out if it would likely fit, and then took the risk of telling them to give it to me and I'd hope for the best. A gamble that seems to have paid off.