Curious to know if any members here have ran on E85 and not meth injection. I was informed that the DME does not need any reprogramming to run on E85 and wanted to see if the gains are significant.

 

I'm new to the Porsche world, coming over from Subaru, i know there you typically need bigger injectors, pump, and a sensor to detect ethanol levels unless your'e running straight E85. I'd assume the stock pump and injectors would be fine on the turbo model but i would think you'd still need a sensor or a tune at least to be able to run E85. Could be wrong though.

 

The stock PCM will not really provide any large HP gains for E85. The energy density in the fuel is less than gasoline, so it takes more of it to make power. In order to deliver the appropriate amount of fuel, you will require at least injectors and a custom tune. Not sure about the pump (as stated above) but Steve knows more than I do about that part, I guess.

Edit: Meth injection is different because it cools the intake charge, unlocking more power in the process. The cooler your intake charge, the more timing and fuel can be introduced by the PCM without creating knock. In order to maximise the gains from meth injection, again, a custom dyno tune is the way to go. The stock tables will only push the engine so far.

 

I Appreciate the insight on this.

 

I don't know a ton about E85. I run it personally in my Subaru STI. From what i understand it burns much cooler than regular octane fuel. For turbo applications. like the subarus, its an easy way to make big power. Like shrike says though it take a lot more fueling. But i wouldn't drive my sti without it. It makes the engine so much more responsive.

 

Run E85 on my GTR but is tuned for it. Huge horsepower difference. Burns approx. 30% faster but cheaper cost balances it out.