E85Forum.com

chenely63 · Joined: 09 Aug 2005 Posts: 27

I would like to have a ethanol gas sensor just so I would know what the fuel mixture is, not that it is needed with the flex tex unit, my unit is working good on the ford ranger four cly.
Leo

Robotbeat · Joined: 18 Jul 2006 Posts: 31

It's good to know that Motronic sensors are pretty forgiving with ethanol, since I have a 1995 saab 900se v6. I currently have 35% ethanol in my fuel tank (1 part e85, 2 parts e10), and I have noticed it actually runs better than running regular gasoline (probably because my "e35" is about 93 octane, whereas regular e10 is 87 octane, and my saab works best on 92 octane or higher fuel). I am going to continue to increase the mixture, and figure out how it works for my vehicle.

Does anyone know how I can find out the details of my motronic system?

jmd1218 · Joined: 08 Aug 2006 Posts: 1 Location: Colorado

I started doing the same thing you are doing 6 months ago and I eventually went to 100% e85 with NO conversion kit. I am 100% convinced that ALL fuel injected vehicles on the raod today can use a MINIMUM mixture of 50 percent e85 and 50% gasoline.

I am also convinced that some cars can do e85 100 percent with NO bi fuel converter. That said when you do more than 50 percent e85 then you may want to look into a bi fuel converter because yoru car will most likely run better with a bi fuel converter.

I use 100 percent e85 in my 1998 Toyota RAV 4 with abosolutely NO problems so far. I have NOT changed my fuel filter either and I have been running e85 (100 percent) since April 2006.

I did run the car off 199 proof ethanol and it ran fine except for climbing hills where it almost died. I have to assume that the fuel injectors did not get sufficient fuel so I plan to buy and install a Full Flex unit so that I can run straight ethnal. Why straight ethanol? ONE CANNOT do that with running e85 for business purposes, To be able to get teh tax credit one has to run striaght etanol of 190 prrof or better to get the $.51 tax credit PER GALLON!

John D

Corn Squeezins · Joined: 14 Dec 2005 Posts: 42 Location: Madison, WI

Where does one get 199 proof alcohol? Why/how does this earn u a tax
credit for it. A litte more insight on this might be interesting....

Thanks!

Corn Squeezins

mtbottle · Joined: 14 Jan 2006 Posts: 46 Location: West Virgnia

Here is a good formula for splash blending of E85.

You can solve this mixing problem by using 2 equations with 2 unkowns.

Assume: X = gallons of E10 (10% Ethanol)
Y = gallons of E85 (85% Ethanol)
50 = gallons of final mix (whatever your final size container)

For 20% Final mix:

equation 1 10X + 85Y = 20(50) = 1000
equation 2 X + Y = 50

solving this gives 43.3 gallons of E10 and 6.7 gallons of E85 (5 gal can would be 4.3 g E10 and 0.7 gal E85)

For 30% Final Mix

equation 1 10X + 85Y = 30(50) = 1500
equation 2 X + Y = 50

solving gives 36.7 gallons of E10 and 13.3 gallons of E85

Acually 25% calculates out to even gallons which would be easier to measure at a E10/E85 ratio of 4/1. (40 gallons of E10 and 10 gallons of E85)
_________________
Duane Combs

specialgreen · Posted: Sat Sep 02, 2006 2:08 pm Post subject:

Just as an update, I'm using 3:1 mix of E-85 (summer) and E-10 now in the VR6 VW Passat, or "E-66". It works better than the 3:1 mix of E-70 and E-10 I tried during last winter ("E-55"). So I'm guessing that there is some variability with climate.

stylin99 · Joined: 08 Sep 2006 Posts: 85 Location: Charlotte, NC

Specialgreen,
Be careful with putting that much ethanol into your car. You're are effectively forcing the air/fuel mixture to go lean and the computer may or may not be able to compensate for that reading. This will be especially important if you are doing any full throttle acceleration runs where the car goes into Open Loop mode and is reading from a predefined set of fuel tables. In Open Loop on the cars I'm familiar with (know nothing about a VW I'll admit), the O2 sensors do not feed back to modify the fuel input and the car will definitely go lean.

And we all know that lean is great for your grilled chicken or on your spouse... but not on the internal combustion engine. Wink

_________________
'99 Mustang GT, Vortech Supercharged, now running E85 full time.
www.e85mustangs.com

Best Quarter Mile on E85:
10.52 at 135 mph

jachristner · Joined: 12 Oct 2005 Posts: 64 Location: Kokomo, IN

I understand why the ECU uses a rich mixture under WOT conditions. What I don't understand is why it uses a fixed table rather than incorporating the fuel trims. Perhaps with gasoline, the difference isn't enough to be any kind of problem. It seems it would be better to set the WOT mixture to a percentage increase over the current fuel trims.

For example, the short-term trim by definition stays near zero most of the time. The long-term trim helps the ECU 'remember' what mixture works best with the previously used type/quality fuel put in the vehicle.

14.7:1 A:F is stoich for gasoline. If 13:1 is desired for WOT, the fuel increase is approximately 13.1%. Why not set WOT mixture as 1.13 x long-term trim?

If the long-term trim of the vehicle has been living at +5%, or so, the WOT fueling from the table only adds 8% instead of the ~13% desired. If the long-term has been negative, fueling from the table adds more than the ~13% desired.