E85 is an alcohol and fuel mixture that contains up to 85% denatured fuel ethanol and gasoline. The ethanol is derived from corn which earns it the nick name “corn fuel.” Because this fuel is comprised of mostly alcohol it has a great effect on performance (more on that in post 3).
To run E85 requires upgrading the fuel system due to the greater amount of fuel E85 requires to be used. Depending on the turbo size this can range from upgrading just the injectors and in-tank fuel pump (for a stock turbo) to a $2,000+ fuel system consisting of huge injectors, multiple fuel pumps, upgraded fuel rails, etc (for a large turbo). It is best to contact your tuner when determining the necessary fuel system upgrades for your build. The build examples in post 9 can be a great resource in determining this as well.