CarbonRevo

Yea, I definitely wouldn't run E85 in a daily driver. Both of these cars are strictly nice weather cars. And running 2 maps will be an amazing thing. Granted, I'll have to carry a laptop with me...

And 25lbs, You think I'll need to run 25 on E85? I guess I was shooting for 21lbs or so. Pipe dreaming? lol

951_RS

I've no idea what boost I'll end up running on my turbo as I'm not even sure what it's capable of running with just 93 octane =/

95ONE

yes, running E-85 in a motor limited to a design for regular pump gas is not economical for an everyday driver. the difference is that you can set boost and timing like you were were running a 110 octane fuel that cost about $8.00 a gallon, on a fuel that only cost $2.14 (As of 10 minutes ago) A ridiculous savings at the track.

On the flip side.. If you actually designed an engine to run on E-85, you will certainly get better gas mileage per btu of fuel. E-85 would allow a 14:1 compression ration on an aggressive timing map effectively increasing efficiency considerably over the gasoline motor that will now make better use of the more efficient burn characteristics. ... etc. etc. etc. I can never say enough good about this fuel.

fast951

When you get the V-FLEX, there will be no need need to run the laptop to switch between E85 and pump fuel. You can install a external switch which enables you to go from pump gas to E85. The software will do the rest for you.

marcoturbo

John, when you run E85 thanks to the v-flex, what are the A/F ratios you want to see ?

I know the "rules" of 11.5:1-11.8:1 at WOT above 7psi and 12.5:1 below this pressure but what is the rule for E85.

333pg333

No you won't 'need' to run bigger boost, just that it's available with E85 as long as everything else is done correctly.
As John points out, with his V-Flex you will have a perfect setup and in cabin control.

fast951

When it comes to E85, I forget about AFR values and just read Lambda. Under load I aim for a range between 0.79-0.81 lambda. At lower boost, you can go a hair leaner.

All Wideband systems read Lambda. The Lambda value gets translated to AFR based on the fuel used. Many Wideband systems allows you to select the fuel type, then convert the lambda to AFR for a particular fuel type (gasoline, E85, Propane,..).

One thing to keep in mind, E85 blend varies based on location and the time of the year. So E85 is not always 85% Ethanol and 15% fuel. In some places 90% Ethanol was reported, other places had Ethanol in the 70s%.

So the conversion from Lambda to AFR will not be accurate. This is why I prefer to view Lambda, much simpler and more accurate.

95ONE

^^^^ Second that information.. As discussed in earlier threads, the Ethanol mixture varies due to REGIONAL temperature. (Cold start issues are exaggerated in colder weather) So, if you live in a colder area, you will be seeing ethanol to fuel ratios at 70% right now. Here in Houston it will be 75-80% because of the warmer climate in the winter. In the summer though, Everyone should be back to the 85% ethanol to fuel.

Lambda IS actually easier (in my mind anyway) to use to tune. Ethanol is more forgiving on the rich side (you don't drop off in horsepower levels as bad as fuel) So, I would check Air fuels now, (The winter season would be the "Leaner" mixture), so tune afr to match .78-.81 and not worry much about the richer mixtures for Spring and Summer. Because like I said, Ethanol is more forgiving when rich, But I would personally check 2 more times, Spring and Summer just to be sure. Adjust as necessary. Shouldn't be much. With Vitesse software, the FQS should be all you need. Or Preferably something as simple as an adjustable Fuel pressure regulator.

DanaT

John,

On a side note with that, E85 is not always available and gasoline has to be run. Lets say I am at 1/4 tank gasoline, and fill up with E85. How does the map know if I am running 3/4 E85 or 100% E85?

Have you thought about adding something like this to the vflex?

http://www.zeitronix.com/Products/ECA/ECA.htm

This would allow more accurate fuel octane mapping. The reason I ask this is I may want to run E85 in my car. I just have to drive a ways to get E85 so I can't count on always having e85.

-Dana

fast951

Dana, the DME has no way of knowing the % of E85 you have in the tank. It is up to you. The software works with fuel or E85, not a mix.

95ONE

That is pretty cool.. Looks like they are selling the stock sensor from the gm cars. Which if true, can be extremely cheap from junk yard. - I have NOT looked in to the details on the linear output of the gm unit. But if you have any decent programmable engine management unit, you can just install this piece and set up the fueling table accordingly. might be a bit intensive depending on your programmable unit.. But it should be a matter of x voltage = y overall fuel trim.

fast951

The GM sensor I looked at is not a 0-5V output, that will be too easy. The output of the sensoris a frequency, which must be converted to a 0-5V output.

CarbonRevo

Was discussing that sensor with some people a few weeks ago. I really wish we could somehow have this incorporated into the V-Flex software. It would simplify these things by ten fold and I think V-Flex would sell like gang busters then (more people less afraid of running E85).

John- The switch, what is it wired into? Is it wired to the Vitesse chip or through the piggyback somehow? I would be glad to have this switch if need be to get me by on 93 until I can get an E85 fill up.

Would one be ok if they had say a gallon or two of E85, then topped it with 93 octane and flipped the switch and stayed out of high boost/no boost driving?

That's my main concern really. If I get home and need E85 for the next cruise, would I be able to get a gallon or two of 93 to get me to the E85 station (22 miles from my house) and just use the switch until the tank is full of E85?

fast951

The switch is external and is interpreted by the DME/software. The PiggyBack can use the same switch or a second switch. Many options, best to take it off line.

V2Rocket

what kinda mileage do ppl tend to get with e85?