well i ordered a diablo sport predator for my 05 5.7 an the gas we got around here has ethanol besides one place, an it has 92 octane "pure gas".
and the only 93 octane has 10% or less ethanol.. so with the 93 octane tune, would it be better to use the jus 92 pure gas or the 93 with ethanol?
an if any ideas, what does the ethanol do to the motor? does it robb power?

 

Ethanol is garbage, avoid it. You lose milage running that stuff.

 

I'm not sure as far as performance goes but I know for sure I gained 1 to 1.5 mpg using Pure Gas.

 

Ethanol has a BTU rating approximately 30% lower than pure gas. Using 10% ethanol will produce approximately 3% less BTUs (BTUs is a measure of energy). It is overly simplistic, but using a fuel with the blend you listed could cost you approximaetly 10hp(345 X 3%), half of what you gained with the programer.

 

Anyone know what gas stations sell pure gasoline anymore? I heard BP gas might not contain ethanol.

 

There is a MARATHON station here that sells 100%. If you have one where you are you might want to check there.

 

Here in NY, I have only found 1 station that sells 100% pure gas. Almost all of them have 10% ethanol

 

the correct blend
of E85 to conventional gasoline
will give a slight increase in
wide open throttle high rpm horsepower

the way to find the correct blend for your engine
is to use a wide range oxygen sensor
and get the air to fuel ratio mixture
of about 87% to 90% of 'equal measure' (also called Stoichiometric )

E85 does not improve MPG

E85 can plug up fuel filters
and cause corrosion of parts designed solely for gasoline

 

i think you're reasoning is power will come from the advance in timing IF your engine takes advantage of the octane increase.

Not sure, but i'm fairly confident that there is a ceiling on how far the motor or even a programmer will advance timing, regardless of what octane it has (or how cold the intake air is). If so, there will likely be no gain by using an e85/gas blend as 93 octane will be enough for the timing at that ceiling.

 

most of the gains
are from the lowering of the IAT
and increased VE
due to the heat of vaporization of ethanol

if the blending is done correctly
a further slight gain
comes from bringing the air/fuel ratio
closer to 'mean best torque' setting
from the factory WOT 'full rich best torque' setting