Ethanol

[Gleb]

I am about to tune/dyno my car and have a quick question...
Race car, M20 with a cam, Miller MAF and tunable chip.
Can use 94 with about 10% ethanol or 91 pure gas.

91 should give me better BTU, 94 should be better knock resistor. I don't think there will be a noticeable difference in power.

Any problems with using ethanol "enriched" gas?

Thank you.

[etxxz]

ethanol has less volumetric energy content than gasoline. it does have a higher knock limit so you can run it at higher compression ratios, but in your case, it'll probably give you less power and you won't even notice it. i think all pump gas you buy nowadays is already 10% ethanol by volume.

[nando]

it's a lower energy content (not VE, that's a function of the head).

it doesn't have higher knock limit if it's still 91 or 94 or whatever. E10 rated 94 will have the same knock properties as regular gasoline rated 94. that's why E10 blows chunks - less energy content (less power, worse MPG) and no real benefit.

also, even on 91, it's unlikely your car is limited by knock in the first place. Put the 91 in, and tune for MBT.

[etxxz]

you're right about the knock limits misunderstanding on my part. same conclusions tho.. pour it, race it you won't feel the difference... ofcourse some butts are more sensitive than others.

[nando]

I bet you would notice a difference on a dyno, as well as fuel economy, and the 91 is probably cheaper.

[Sagaris]

:hitler: Ethanol from corn is a horrible idea. That is all.

[etxxz]

....boy what a nice conclusion.

You take the red pill - you stay in Wonderland and I show you how deep the rabbit-hole goes. The solution to nothing nowadays is neither or, but a combination of, a compromise and optimization, a "globalization of methods". Examples: gas, pure electric or pure fuel cell vehicles? Solar, Coal or Nubclear? Personalization or massification of education?... you're better of taking the blue pill today..

[nando]

I'll take some E85, please

but E10 is a total waste of time..

[Fusion]

The scandinavian guys are doing some whacky shit with pure ethanol and turbo engines.
Yes you can gain power by running ethanol, but have to be really "scientific" about it.

[e30s50dan]

Take the blue pill Mr Anderson