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It is true that you can get more power naturally apirated using ethanol instead of gas. If you make a simple conversion from gas to E85 you will make about the same power. By only adding fuel you loose a few hp. If you optimize timing you gain some again, but the hp will be almost identical as the optimized gas engine.
To gain power naturally aspirated you need a purpouse built engine with higher compresion that is optimized for the ethanol fuel. A FLEX FUEL vehicle is not. It is has a gas engine that can run on ethanol also.
On a turbocharged engine you can raise boost to take advantage of ethanol. Raising boost is similar to raising compression on a naturally aspirated engine.
An example is the FLEX FUEL vehicle SAAB Turbo. It produced 150 hp on gas and 180 hp on E85. That is 20% more.
I just don't see a basically stock engine switching to E85 and making more power. If you build a high compression motor built specifically for E85, and to make power that way, then that's a different story.
joby, the stock oxygen sensor can be used when switching over to e85?
let's hear about how to make it work in a c4.
the only problem i see is how to make a stock maffed ecu work with e85. any ideas.
The stock stock oxygen sensor works just fine with E85 and the ECM does not have to know anything about E85.
As I said before you need about 30% more fuel volume.
You have a few options to do that.
1) You can create a custom chip. If you change the injector contant to fool the ECM that the injectors are 23% smaller than stock, then the ECM will keep them open 30% longer.
2) Install a AFPR and raise fuel pressure by about 70% ( 43 psi to 73 psi ). That will increase the flow by 30%. You might need a new fuel pump too if the stock pump can't deliver that pressure with enough flow.
3) Install larger injectors. Stock injectors are 22 lb and 30% more are 29 lb.
1 and 2 are easy to return to stock at any time if you have to fill the tank with gas somewhere.