E-85 With Canned 93 Performance Tune

[2010F150]

Will it be fine to run E-85 with my canned 93 performance tune until my custom tunes are sent?

[shotgun]

Not unless the E85 has a 91+ octane.

[2010F150]

its 102 octane just making sure it wont cause a lean condition

[shotgun]

Ford's OBDII system uses the O2 sensors to measure and then compensate for the higher alcohol content by adjusting the target AFR. This should eliminate the possibility of operating in a lean condition.


If the R+M/2 value is truly 105 (there is considerable debate on this true octane value), you should be able to advance the timing up to 6 degrees (this is the theoretical max based on 1/2 degree for each increase in octane; [105 - 93] / 2). <---Someone please confirm my memory!

Obviously you should make small changes until you detect knocking. If you advance too far (too quickly) the knock sensors will dramaticlly reducing the timing advance.

The relationship between PM and AFR is shown in the table below.

Stoich Air Fuel Ratio = 14.64 - 5.64 * PM

PM (percent alcohol)...Stoichiometric AFR
0.00 (100 % gasoline)...14.64
0.05... 14.36
0.10 (standard gasoline)... 14.08
0.15... 13.79
0.20... 13.51
0.25... 13.23
0.30... 12.95
0.35... 12.67
0.40... 12.38
0.45... 12.10
0.50... 11.82
0.55... 11.54
0.60... 11.26
0.65... 10.97
0.70... 10.69
0.75... 10.41
0.80... 10.13
0.85 (standard E85)... 9.85
0.90... 9.56
0.95... 9.28

1.00... (100% ethanol) 9.00


If you intend on using E85 all the time, I would recommend you discuss this with Bill (if you haven't already). He might be able to write your performance tune based on E85 (or even write you an E85 performance and towing tunes since the CS and CTS are capable of storing up to 20 tunes).

[cleatus12r]

It's going to run REALLY lean.

Just throwing that out there. There is more to this than just the octane rating of the fuel.

Thanks for throwing that list up there, shotgun!

[Jackpine]

Originally Posted by cleatus12r

It's going to run REALLY lean.

Just throwing that out there. There is more to this than just the octane rating of the fuel.

Thanks for throwing that list up there, shotgun!

Cody - why do you say that? I don't think I understand at all.

He's got a "flex-fuel" truck, which has been designed to burn the E85 crap and, like shotgun says, it should adjust the A/F mixture for the proper stoich (9.85) as long as that fuel is being burned.

Are you saying that the canned performance tune will try to hold the A/F ratio at or near 14.64 regardless of the fuel used? If that's the case, I understand and yes - I would not use ANY of the canned tunes with the fake gas. But, as you can tell, I didn't think it would work this way. Can you clarify?

Thanks in advance my friend. Hope you're staying warm up in the frigid north country!

- Jack

[cleatus12r]

I was unaware that he had a flex fuel truck.

[Jackpine]

Originally Posted by cleatus12r

I was unaware that he had a flex fuel truck.

Ah - I see. As far as I know, all 08+ trucks are flex-fuel and he seems to have a 2010, looking at the screen name. (Of course I'm performing a WAG here, aren't I?)

On a slightly related topic though, I wonder how they create a 102 octane mixture using E85? As shotgun implies, I don't think the real (R+M)/2 octane rating is that high, just from adding corn alcohol. (And shotgun, you're right about adding 0.5 degrees of timing for every octane number. But, he said the octane was 102, so the timing advance would be (102-93)/2 = 4.5.)

To the OP - are you in Canada? Your name tells me you possibly are, and if that's the case, you may be seeing an octane rating that is "Research", not the "Research + Motor" average. The pump should tell you this. If it's "Research", the (R+M)/2 rating will be quite a bit lower and I'd be a little careful adding timing. I'd guess maybe the (R+M)/2 rating might be around 95?

- Jack

[Skip_1074]

Okay so this topic begs me to ask the question, when getting a custom tune written, should I have specified that we are running E10-E15 where I live? I do have a FFV 5.4L, but do not know if that will make a difference in the tuning. I thought that I read somewhere that Bill pretty much is writing custom tunes for E10 anyways as it has become the normal fuel throughout many parts of the country.

Just to clarify, the 5.4L is a FFV, the 4.6L is not (at least that is my understanding from reading Ford's specs while researching trucks).

To the OP, sorry for the hijack, but shotgun got me thinking.

[ticopowell]

It can never hurt to give Bill more information, but he does already take into account the E10, and your truck should be able to compensate for the E-15 even if it isn't FFV.