Converting to E85 ethanol is one of the most popular modifications for those looking to maximize their vehicle’s performance, while also offering economic savings and greater environmental sustainability, thanks to the renewable source from which this fuel derived.
E85, a blend composed of 85% ethanol and 15% gasoline, offers a significantly higher octane rating compared to traditional gasoline, increasing from around 95 octanes for gasoline to 105-110 for ethanol. This allows a higher compression ratio without the risk of knocking, in addition to reduce engine operating temperatures, resulting in an overall performance improvement.
However, converting to E85 requires specific modifications to the engine control unit (ECU) as ethanol has different combustion characteristics compared to gasoline.
To convert a vehicle to use E85, no mechanical modifications are needed, but adjustments to various ECUs’ parameters are required:
This is the first essential step: modify the injector calibration map so to increase the injector opening time to ensure a greater fuel supply. In some ECUs, it is necessary to adjust other maps such as injection enrichment, MAF sensor coefficient or volumetric efficiency, following the same principle of modification.
Adjusting the “Factor Cold Start” maps is crucial to overcome one of E85’s challenges: its greater difficulty in vaporizing compared to gasoline, especially at low temperatures.
Finally, modify the ignition timing that allows performance enhancement by making the most of E85. The fuel’s inherent properties enable the engine to handle increased timing effectively.
Ethanol conversion on Honda Civic Type-R FK2/FK8/FL5: Thanks to the maps available in the driver for the Bosch MED17.9.3 ECU equipped on the Civic Type-R FK2/FK8/FL5, it is possible to perform the ethanol conversion with great precision.
This example will provide you the necessary information to tackle the E85 conversion on this type of ECU. Learn how to work on injector calibration maps, the “Factor Cold Start” and ignition timing to achieve the best results. We will use the ECM Titanium software for these modifications because it allows you to:
