Any reason we can't blend in some e85 for knock resistance?

[05yellowgt]

Well if I had a tuner I would just have him write me an e85 tune and run it 100% but that's not the point. Nevermind.

If I have to I might spring for an AED or Lund E85 tune. Currently have Bama tunes and they don't offer anything corn related.

You have tunes, so you have a tuner. Bama by the looks of the rest of this post. They should be able to send you a tune with just the stoich changed without little to no problem.

 

[cbrtrx]

What benefits did you see with this? Did you see less KR like I would think you would, did the car feel better, etc?

In my area we have 93 octane and I tune myself so I can always adjust my timing accordingly. I saw minimal gains and some knock supression. For you it may just give you enough to run your tune without it pulling timing, if not you're just back to where you started so nothing really lost.

 

[Seer]

Your stoich would change from 14.1 to 13.5 going from e10 to e20. A difference of about 4.4%. That's well within the parameters of what the stft and ltft can correct for.

I don't really see the harm but it's not my car and not my risk. Plenty of people run e10 with a gasoline tune. Gas is 14.64 and e10 is 14.1, a difference of about 3.9%.

I would view running e20 on an e10 tune no different than running e10 on a gasoline tune but that's me.

Seems like most tuners tune for gasoline and just expect E10 to be mixed in.

This being said OP, Torco's new formula seems to be a better idea. It is genuinely safe for unleaded cars now.

 

[BruceH]

Seems like most tuners tune for gasoline and just expect E10 to be mixed in.

This being said OP, Torco's new formula seems to be a better idea. It is genuinely safe for unleaded cars now.

I set my tunes up for 14.1 on pump gasoline. It doesn't surprise me that there are tuners out there still going with 14.64. What's the default for a 5.0 stock tune? I'd hope it's 14.1.

 

[beefcake]

Don't the factory 02s just work off lambda? Don't you tune for the same lambda (e.g. 0.84 at WOT) on E85? Won't it try to maintain the same lambda no matter what fuel is in it?

So what you are suggesting is that if I (for example) just replaced my tank of gasoline with e85 and didn't change the tune, there would be no codes thrown due to running lean, the fuel trims wouldn't change, but the car would be running ~30% leaner? I disagree, I think that the fuel trims would come in to play and the computer will begin adding long term fueling if I don't go crazy with the amount of E85. Obviously I would not just run a full tank of corn because I'm sure that 30% is way too much for the fuel trims to account for.

It's your engine, feel free to disagree.

fyi, lambda of .84 on gas gets you an a/f of 12.29

lambda of .84 on e85 gets you an a/f of 8.27

whatever you "mix" is going to change to somewhere in between that.

yes, the computer will try to achieve the lambda you are commanding. But it is going to base this off the information you provide to it. You are telling it is has a stoich of 14.64

then you start dumping in fuel with a stoich of 9.85. How do you expect the widebands to know this information?

the car will definitely be leaner

 

[KrisR]

It's your engine, feel free to disagree.

fyi, lambda of .84 on gas gets you an a/f of 12.29

lambda of .84 on e85 gets you an a/f of 8.27

whatever you "mix" is going to change to somewhere in between that.

yes, the computer will try to achieve the lambda you are commanding. But it is going to base this off the information you provide to it. You are telling it is has a stoich of 14.64

then you start dumping in fuel with a stoich of 9.85. How do you expect the widebands to know this information?

the car will definitely be leaner

Have you tried it or are you just guessing?

Do you tune or just have Lund do it for you? Honest question.

To me, the car will trim fuel to the correct lambda, which automatically gets you to the correct air fuel, no matter the stoich. If I dump in e30 for example and fuel trims are suddenly adding 10%, it's achieving the correct a/f ratio for that fuel. I don't see how it could work any other way.

The car doesn't care what the stoich of the fuel is. It cares about maintaining the commanded lambda, which is what everyone tunes for anyway because that gets you to the correct air/fuel for whatever the stoich of the fuel, and it maintains lambda by using the o2 sensors and adjusts accordingly.

Honestly if I can be proven wrong by someone who has tried it, I will stop replying.

 

[DSargent09]

Have you tried it or are you just guessing?

Do you tune or just have Lund do it for you? Honest question.

To me, the car will trim fuel to the correct lambda, which automatically gets you to the correct air fuel, no matter the stoich. If I dump in e30 for example and fuel trims are suddenly adding 10%, it's achieving the correct a/f ratio for that fuel. I don't see how it could work any other way.

The car doesn't care what the stoich of the fuel is. It cares about maintaining the commanded lambda, which is what everyone tunes for anyway because that gets you to the correct air/fuel for whatever the stoich of the fuel, and it maintains lambda by using the o2 sensors and adjusts accordingly.

Honestly if I can be proven wrong by someone who has tried it, I will stop replying.

It's become evident that you will not be proven wrong being that no one has been dumb enough to attempt this with their vehicle. So why don't you stop having a debate with yourself and provide us with some entertainment. Maybe it will work maybe it won't. But it appears it hasn't been tested and people are clearly advising you against it.

 

[KrisR]

It's become evident that you will not be proven wrong being that no one has been dumb enough to attempt this with their vehicle. So why don't you stop having a debate with yourself and provide us with some entertainment. Maybe it will work maybe it won't. But it appears it hasn't been tested and people are clearly advising you against it.

Thank you for your brilliant contribution.

 

[DSargent09]

You're welcome. Seriously though- try it, data log it, and lets see what happens. I'm sure I'm not the only one that has been silently following this thread out of curiosity.

 

[KrisR]

When I used to switch between fuels in my 05 GT, I would occasionally fill up with e85 and drive a few miles back to my house before loading an e85 tune. By the time I got home it was already adding up to 25% fuel via the fuel trims (again trying to maintain 1.0 Lambda at cruise/idle) and it actually ran fine, no issues. Obviously I could not get out of closed loop without it going way lean because the 02 sensors were ignored during open loop and it would run way lean.

Seems to me that the beauty of these newer cars/processors is that they also correct fuel via ST and LT FT at WOT also.

Honestly I didn't mean to ruffle any feathers.

Next fill up I'm going to try a few gallons and see what it does. If fuel trims don't change I will know it's running too lean and I will go back to pure pump gas, no big deal.

 

[KrisR]

Side note, even if it doesn't add fuel through fuel trims, I would rather have it run at 13.0 AFR at WOT on corn than 12.0 with shitty pump gas. I used to see mid-12 air fuel on my 99 GT at 24lbs of boost quite frequently on e85 and it loved it. It also 'lean cruised' at 15.5-16.0 air fuel at light throttle and it always ran great.

 

[beefcake]

again, it's your car, your more than welcome to tune it how you see fit

good luck with that

and lund does our tuning,

 

[KrisR]

again, it's your car, your more than welcome to tune it how you see fit

good luck with that

and lund does our tuning,

Like I said, I will give it a shot with the next fuelup. If I add 4 gallons of corn to 12 gals of gas and the fuel trims climb to the +8% to +10% range, I will know that its adding the correct amount of fuel through the trims to compensate and maintain correct fueling. I will do some datalogs to see how the spark/KR react.

If it doesn't work, I will give up on the idea. Thank you for your input, honestly.

 

[cbrtrx]

Like I said, I will give it a shot with the next fuelup. If I add 4 gallons of corn to 12 gals of gas and the fuel trims climb to the +8% to +10% range, I will know that its adding the correct amount of fuel through the trims to compensate and maintain correct fueling. I will do some datalogs to see how the spark/KR react.

If it doesn't work, I will give up on the idea. Thank you for your input, honestly.

Start off with 2 gallons E85 to 12 gallons of 93 or what you have available. The trims should barely move and you should also get enough knock suppression.

 

[Justinjor]

This thread has potential but it would be wise of the OP to listen to some people in this thread(beef, cbr). Post #25 nailed it right on the head.

CBR and I have messed with blends in our cars for awhile. It did provide some benefit but the hassle of constantly having to maintain the correct mix quickly outweighed the minor benefits, at least as far as I was concerned. I switched back to 93 about about a month of testing.

We are fortunate here in Florida to have good quality gasoline all over the place in addition to E85 stations but I could see it being worth the hassle if you simply cannot get a good 93 octane fuel in your area.

 

[stkjock]

a blender pump would make things a heck of a lot easier

 

[Seer]

It would be nice if SCT had flex fuel sensor support like HPTuners does for GM vehicles.

Detects fuel, and advances or retards timing based upon what it finds and corrects the commanded stoich as well without the need for a reflash.

 

[05yellowgt]

It would be nice if SCT had flex fuel sensor support like HPTuners does for GM vehicles.

Detects fuel, and advances or retards timing based upon what it finds and corrects the commanded stoich as well without the need for a reflash.

It is more of an issue that GM ECU's support using a fuel composition detector, and Ford ECU's don't than whether or not SCT supports it or not.

Ford relies on the short term and long term fuel trims on flex fuel vehicles to make the decision as to what fuel is in the tank and what timing and fueling tables to go with. This may be done slightly differently in newer, wideband equipped FF Fords.

SVO/SVT did use an active fuel sensor on the SuperStallion Concept. I personally wish they would have kept that method. (by far the best looking sn95/new edge body style IMO)

 

[stkjock]

It would be nice if SCT had flex fuel sensor support like HPTuners does for GM vehicles.

Detects fuel, and advances or retards timing based upon what it finds and corrects the commanded stoich as well without the need for a reflash.

dont the OEM flex fuel cars come with such sensor from GM, that what would seem to be me to enable such features

 

[19COBRA93]

I didn't read this entire thread, so I'm not sure which direction it has gone, but... I mixed 2.5 gallons of E85 into 91 for 2 years with great success.

A couple years ago I was running a little more boost, and possibly a little more timing, than I should have on 91 octane and a stock 3V. I would get some detonation at WOT when running pure 91. So, I had my tune richened up a bit (about 8-10%), and started mixing in E85. I did play around with how much to mix in, and how much to richen up the tune, but it didn't take long to get it nailed down. I ran it that way for 2 years and about 30,000 miles without a problem.