Savington

iTrader: (31)

I'm well aware of the benefits of E85 and the tuning limitations of boosted cars on gasoline, but that wasn't what I was referring to. Empirical tests have repeatedly shown E85 to make more power than gasoline. My best example is on a 300whp turbo car using 100 octane and water injection (i.e. no timing limitation). Switching to E85 without altering the timing map at all resulted in ~325whp. I understand that changing to E85 alters flame speed and can change the point where peak pressure is seen in the engine, but I'm talking about seeing 5-8% gains in cars that are already at MBT.

If there's no obvious reason for the power gain, then it must be in the flame speed or charge density or something else.

This, except I think you meant "burns faster and results in higher average cylinder pressures".

triple88a

iTrader: (2)

Perhaps something along the lines of flame speed with an exponent of some kind.. aka slower at first but faster as more fuel gets ignited. So more of it gets used on the way down?

shlammed

iTrader: (8)

more like it is more stable so it isnt suseptible to detonation. but once its ignited has a crazy power potential.

Dunning Kruger Affect

Except that E85 has significantly less energy density than straight up gasoline.

Savington

iTrader: (31)

Energy potential doesn't work this way.

triple88a

iTrader: (2)

Do the 30% increase in fuel you get fairly even numbers.. then you add some for the extra spark and efficiency gain and thats how you get the more power out of the E85.

Dunning Kruger Affect

Oh yeah, I agree. Just talking numbers, 100% Gasoline is 33% more energy dense than E85.

The basic formula for power in an engine is fuel + air = power, more fuel and more air = more power. I am on the E85 is magic train, but the reasons why you can squeeze out extra power probably comes from the higher efficiency of the burn cycle since not as much energy is lost as straight up heat since ethanol burns so cool.