E 85 is 35 % oxygen by weight. Oxygen is the precious commodity that allows the internal combustion engine to make more power. Almost every modification,we do to a motor,is done to get more air into the motor. The air entering the motor is only 22% oxygen. Most of the air we breathe is space wasting inert gasses such as nitrogen. If we can get more oxygen into the motor in some other way than the air we breathe,it's a good thing. One way is by injecting nitrous oxide. Nitrous oxide is a gas that is 33 % oxygen. More oxygen allows us to burn more fuel . This is were the increased power comes from. Every time we add 11 parts of oxygen we can add one part of fuel,so you can see that oxygen is the thing we need the most. When we get more oxygen by introducing more air into the motor,the vast majority of what we are adding is inert gasses that take up space and bring nothing to the party.
Methanol,Ethanol,and Nitro Methane get more oxygen into the motor because it's in the fuel. That's why these fuels make more power than gasoline.
If you do nothing to the motor and switch to E85,you will make more torque and your turbo will spool up twice as fast. You'll fall in love with it,then you'll increase the boost and advance the timing and fall deeper in love.