E85 and a T-Spark
I'm not sure how much people know about E85, it's a blend of 85% Bio-Ethanol and 15% Unleaded. It has a higher octane number than petrol so it's more difficult to ignite. It's currently used in FlexiFuel Vehicles which have a smart ECU which can adjust the fueling and ignition timing to run on E85, regular unleaded, or any mix of the two. Here in ireland, E85 costs approximately 30% less than regular unleaded, there however is a mileage penalty, but nowhere near the 30% mark. In addition to this, there is a significant environmental benefit.
Just looking at running E85 with no unleaded mixed in, the fueling needs to be increased and the timing needs to be retarded. The thing is, with a twin spark, it should be possible to achieve better burning of the E85 i.e. each spark helping things along, potentially making it ideal for conversion. I'm throwing this open to any of you who might have played around with the ECU settings to get your take on it, how difficult would it be to increase the fueling and to retard the ignition timing?
Warning: One big caveat in all of this is materials compatability. Ethanol is a strong solvent and may degrade some rubber or plastic components in the fuel system so a little reasearch into the materials needs to be done before going out and filling up with E85.