I have a 67 Chevelle with a iron head 502 crate, tremec 5 sp, Street and Performance Ram Intake with 36 pph injectors and it is all controlled by a ACCEL Gen 7 DFI unit.  The DFI unit runs on a narrow band Ox2 sen but I have another bung on the other header where I put a wide band unit for my Innovate unit.  I do my own tune via laptop; currently it does 378 RW HP and runs great and even gets good mileage if I can stay out of it, typically 17-19 Highway MPG.

I am thinking that conversion to run E85 might be an interesting project to respond to the coming gas prices this summer.  Although the mileage will suffer the current price of E85 is $1.80 vs. $2.85. 

Does anyone have any experience running alcohol or E85 using a set up close to mine?  I have braded lines and some rubber components in the fuel supply system so that might be issue.  Assuming that I am on to something fun here what enrichment ratio should I try as a starting point?  If 14.7 is stoichiometric for gasoline what should be the ratio for for E85?  I know that the OEMs have E85 vehicles that go both ways, could it be a simple tuning issue or even just fill up and go? 

pretty much impossible to convert legally. check out
http://www.e85fuel.com/e85101/faqs/conversion.php  

No doubt there is a law against almost everything... Hollowing a cat could cost a shop like $20000 I'm told.

Anyway if still interested in info on how to, read the "FLEX FUEL" section of Ford's OE manual. Mainly theory and operation. Tells specifically, injector pwm, how much pcm increases fuel pressure, and timing. Fuel Flex is set up with a sensor on the single fuel line which determines what fuel on the fly and calibrate Air/Fuel ratio. Fuel pres. regulated by modulated pump and pcm controlled regulator/pressure sensor on the rail. For gas 40-60psi, ethenol 80psi.

Also, uses same fuel lines steel and plastic with quick disconnects

I have a bit of experience with running E85.
Comming up with a stoich ratio for E85 is really quite simply a bit of math,.. 9.0 (ethanol's stoich)*.85 + 14.7*.15 = about 9.85:1 Which would be ok for a cruise.
max power is found richer (as it goes with gasoline) at about 7:1

If you look strictly at a BTU standpoint, you can see lots of things by this conversion. First that depending on where you live, MN for me so with already have E10 gasoline,(10% ethanol) there is about a 28% reduction in milage. This is directly proportional to the 28% reduction is BTUs. For someone living in another part of the country, you will see about a 30% reduction in milage... so a good starting point would be an enrichment scaler of around 1.28-1.30.

Not sure exactly how your DFI unit works, does it run in a closed loop setup that actaully takes O2 signal into consideration for the fuel trim? Some aftermarket EFI systems are speed density, so they calculate the fuel mix. What I'm getting at is that a narrow band O2 sensor will not work; and am doubtful that your unit will support a wide band.

You could still make the system work w/0 the O2 sensor, just good bye that nice 17-19 Hwy milage. Hope this helps..at least some.


JC