E85

Prepping and driving your Midlana at an autocross or trackday event.
jdogma
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E85

Postby jdogma » 13 Jan 2014, 22:00

E85 might be a great option for track day/time attack like you do. Unfortunately it is not suited to longer events unless you want to carry a buttload of fuel. I considered it for our car but with NASA's 40 minute races, our 20 gal tank would be too small (by my calculations - will have better data to go on soon). The lower btu value requires that you burn more to make the same power, and even more again for greater power.

Midlana1
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Re: E85

Postby Midlana1 » 14 Jan 2014, 06:39

You'd think that gas stations near tracks would add an E85 pump to cash in, but they either haven't figured it out, or it's not profitable. The nearest source of E85 is about 50 miles from Willow Springs. From a brief Interwebz search, it looks like it's about 1.3 lbs ethanol / hp / hour. Say 450 hp at the crank * 1.3 / 6.6 lbs/gal = 88 gallons per hour. Of course, the engine isn't at full power ALL the time at the track, so figure maybe 2/3 of that(?), or about 60 gallons. Ugh, either I did the math wrong or that's completely not doable. I'm not sure if the above math is pure ethanol or if it's E85. However, even if total consumption is less, say, 40 gallons, that's still eight 5-gal jugs, and even that may not be enough for a weekend.

Or, just leave it alone and be happy...

jerelw
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Re: E85

Postby jerelw » 02 Jan 2015, 16:35

One thing I don't like about today's fuels and tuning is that you don't really know what you're getting from the pump. Normal fuel is "up to" 10% alcohol. Even E85 isn't always 85% alcohol. There are three grades of E85 for summer, spring/fall and winter and when grades are switched varies by state (See DrkPhx's post at http://ls1tech.com/forums/fueling-injec ... oblem.html) . FlyinMiata is selling a sensor that fits in the fuel line that senses the alcohol content. If you could integrate that info into the fuel map, you could run anything and not blow the motor up.

Midlana1
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Re: E85

Postby Midlana1 » 02 Jan 2015, 21:05

It's one reason that I'm going to upgrade to an AEM Infinity ECU. It has the ability to work with a GM flex-fuel sensor, so it's entirely possible to have a continuous fuel map from pure gas to 85% ethanol that's always correct. It also does closed-loop boost by gear, meaning that you tell it to go to X psi, and it just does, not like the Hondata where you tell it duty cycle and hope that's close.

jerelw
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Re: E85

Postby jerelw » 28 Jan 2015, 12:23

Check out the Ronin RS211. He runs 95 octane fuel up to 20psi boost then injects isopropyl alcohol into the fuel system for the remaining 12psi. E85 on the fly!
https://www.youtube.com/watch?v=8UZNDEaDlro
680 hp from 1.8 liters!

Midlana1
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Re: E85

Postby Midlana1 » 28 Jan 2015, 17:51

I don't see that as being much different than methanol injection, which has the same potential problem: running out of the stuff "mid-boost." It's one of the reasons I'm going to a flex-fuel setup. Yes, I have the failsafe monitor and the irony is that it's what messed up my weekend, thinking that meth flow was too high. It shut the system down and retarded the boost as it should, caused by me setting the high-flow limit too low*. Apparently the system sees different flow rates when under hard cornering.

Summed up, I don't like having so much on the line for a secondary tank of "fuel", meth or alcohol. I rather just count on one tank so the worst that happens is running out of it, not running out of a critical secondary fuel source.

[edit] Turns out this wasn't the cause of the drop in power - the air scoop was getting sucked flat, only that took me another 8 months to figure out!

Midlana1
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Re: E85

Postby Midlana1 » 21 Jan 2016, 07:28

jdogma wrote:E85 might be a great option for track day/time attack like you do. Unfortunately it is not suited to longer events unless you want to carry a buttload of fuel. I considered it for our car but with NASA's 40 minute races, our 20 gal tank would be too small (by my calculations - will have better data to go on soon). The lower btu value requires that you burn more to make the same power, and even more again for greater power.

My datalogs showed that I'm rarely at full throttle on-track; the rest of the time is spent "negotiating" turns. The Willow Springs event used roughly 5 gallons of E85 per 20-minute session.

As far as availability goes, since we bring our own fuel to the track for both efficiency and cost reasons, it doesn't matter whether it's gas or E85, which was the final straw in deciding to switch to it.


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