Question: Pump e85 + Boost

[Supreme_5.0]

Looking to go boosted soon and I plan on getting a fuel system to run e85. However, the pump e85 around me always tests around e70. Would this be an issue with an e85 tune? If so, are there other options or am I SOL?

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[Andy13186]

Should be fine. I think you can run basically the same timing on anything over e50, just different AFR. Im not a tuner but Ive had e85 and e50 tunes that run the same timing and make the same power. Ask the tuner you plan to use.

 

[daSNAK3]

E70 will be fine. Your tuner should review your logs anyways.

 

[Cordero1]

Winter blend pump Korn usually tests at 70 in many regions. A pump E85 tune is usually tuned for E70-E85. An E85R tune is the one that will require the fuel to be more 85 than not. At least that's the way a couple of tuners have explained it to me.

 

[robvas]

Should be fine. I think you can run basically the same timing on anything over e50, just different AFR

the two old papers I have seen that stated this, one was a low compression turbo engine and the other was NA

I would like to see some recent input from a Coyote tuner on this front, since there are reports of people getting e50 or other blends that aren't "true e85" and seeing lots of knock etc

also what would be the point of the different afr? Sure richer is a little safer/cooler but it wouldn't make up for that big of a gap, would it?

edit: forgot when the mix is different you need a different target

 

[engineermike]

With ethanol, you get huge benefits from the first bit and then diminishing returns, see attached pic. I have mine set to add “all the timing” at anything over about 50% but this could probably be lower. Btw gdi compounds the effects of ethanol.

@robvas the AFR would be 9.8/1 at 85% but 12/1 at e50. You set the AFR in the tune and if it’s not right then fuel trims are off. Or do flex tuning and let it learn the AFR.

 

[Racer5973]

the two old papers I have seen that stated this, one was a low compression turbo engine and the other was NA

I would like to see some recent input from a Coyote tuner on this front, since there are reports of people getting e50 or other blends that aren't "true e85" and seeing lots of knock etc

also what would be the point of the different afr? Sure richer is a little safer/cooler but it wouldn't make up for that big of a gap, would it?

edit: forgot when the mix is different you need a different target

Need more fuel with higher alcohol levels so different afr.

 

[barkingspud]

Here's a nice little table I use when tuning at various ethanol levels. I run less timing at 70% ethanol and below. At 75%+ it's all the timing. For example - Boosted application 1000+WHP Stock Gen 3 block.

 

[barkingspud]

Looking to go boosted soon and I plan on getting a fuel system to run e85. However, the pump e85 around me always tests around e70. Would this be an issue with an e85 tune? If so, are there other options or am I SOL?

To answer your question, E70 is fine. Work with your tuner on a plan.

 

[illtal]

the two old papers I have seen that stated this, one was a low compression turbo engine and the other was NA

I would like to see some recent input from a Coyote tuner on this front, since there are reports of people getting e50 or other blends that aren't "true e85" and seeing lots of knock etc

also what would be the point of the different afr? Sure richer is a little safer/cooler but it wouldn't make up for that big of a gap, would it?

edit: forgot when the mix is different you need a different target

It depends on the Tune and the Tuner how they have the base timing, and "learned" advance set up. Coyote can "learn" that the gas is good (read: more available octane) and allow more timing, whatever is in the tune.

 

[engineermike]

The gen2 pcm logic isn’t capable of floating timing up and down with learned ethanol content. Flex tuners were basically just allowing timing to run into knock every wot pull and hope it doesn’t do damage before knock sensors catch it. It came out recently that they were using this same mentality/“strategy” on the gen3 which totally is capable of adding timing as it learns more ethanol.

As far as knock/octane learning goes, I tried this on a gen3 and was unsuccessful in making it work. I haven’t seen any gen3 with working octane learning yet. Not saying it can’t be done with pcmtec, but when I tried it at least the parameters available in hpt weren’t enough to get it going. I believe the gen2 can be setup to learn octane and float the timing up and down with it.

So to summarize (in my experience) gen3 timing can float up and down with ethanol but not learned octane. Gen2 timing can float up and down with learned octane but not ethanol.

 

[barkingspud]

Not sure I was clear. Flex Fuel and Boost will NOT work! I create different tunes based on the intended application. If you're going to run 93, E60 or E80, that's three different tunes.

 

[engineermike]

@barkingspud are you tuning yourself? If so what software?

 

[barkingspud]

@barkingspud are you tuning yourself? If so what software?

HP Tuners

 

[engineermike]

HP Tuners

What’s your reasoning for avoiding flex under boost? Just curious.

Hptuners, you may already know, is missing about 20 tables that are needed to make flex work right on a gen3 coyote or f150 ecoboost.

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