Let's talk about alcohol

According to testing done by this magazine the use of E85 in a Mazda Miata resulted in a 8 horsepower and 11 foot pound gain over 87 octane fuel . That's without exploiting higher compression or super/turbocharging. "possibly one of the least expensive horsepowergains per dollar we've seen......."

List price of the Flex fuel option on my new truck is $100.. with the discounts, rebates, holdbacks etc.. it cost the dealership around $70. Subtracting the price of the emblem on the tailgate that option probably cost around $30 to Ford..

I can tell you, you will really feel a difference between 87 octane pump gas and E85. It's like it's got another 50+ horsepower with E85. OK Ford tells me I'll get 25% less gas mileage with E85 but it sells for about the same discount. So the cost per mile isn't dramatically changed..

I know the bad myth's about alcohol.. but most of the bad ones are about Methanol and not Ethanol.. Let's make things simple. Corn liquor is Ethanol.. Methanol is usually made as a byproduct of coal Ethanol in moderation you can drink it.. Methanol is poison! Drink even a little bit and you'll go blind or die..

Methanol will quickly cause corrosion. Ethanol needs to attract enough water and that water contaminated fuel has to sit around long enough for the water to cause corrosion.. Most of my S.U. carbs have no damage from the effects of corrosion but I have seen a little minor etching in a few float bowls. I suspect it's because the Ethanol alcohol evaporates quickly enough that it doesn't have time to attract enough water to damage things..

Well ethanol is 113 octane, so theres that. I think i would like to do an ethanol build for the mustang, but ethanol is kind of hard to find in my area, which is ironic because i live in corn country.

We got some Folks 'round here that can show you how to brew your own,I mean Process your own for the car .

when I was younger I worked in a shop that refreshed engines for the Mid-west Outlaws,but it's been only recently that the fuel has been availible, I know of only 1 station that carries it and if folks don't start using it that is likely to go away too.

It's a little over 2 bucks a Gal. and sunoco 101 is 9 bucks a gal.

Its my understanding that On a carbed vehicle you need a special carb, is that correct? What else would you need? Beyond need, what would be the "ideal" ethanol NA street build, as far as things like compression ratio and such?

OK, OK, OK... I get it. It's time to quit. You don't have to call me out in public like this.

Huckleberry wrote: OK, OK, OK... I get it. It's time to quit. You don't have to call me out in public like this.

No, he's saying you need 25% more.

Real world: 2005 flex fuel avalanche

14.5 mpg on 87.

3mpg on e85. Yes, i burned 25 gallons in 75 miles. Stuck with regular 87 after that.

The real question is how much power will it add to a v12 jaaaaaaag

I've been strongly considering this for the giggle power available in my 135i with a tune. There's a station right at the corner outside of my neighborhood that has it, and another right near my place of employment.

In for further discussion.

This is relevant to my interests.

Q: if I have a turbo car that is at (let's assume for easy discussion) the max power the turbo can provide on normal gas, do I stand to gain anything by switching to e85 (I know id need a crap ton more fuel capacity in pump and injectors) without changing turbo?

Just wait until the Biobutanol and Isobutanol blends come out and replace Ethanol, you'll see 400-600HP 1.6L motors with little to no turbo lag.

the alcohol carbs used 102 jets where the Gas used 89-93's. to me (dog gone Pat that's awful)the down side is the water attraction it Hydrates itself insanly but all other things being equal for performance it's better you can run 14 to 1 compression for better results(POWER) and in turbo or Blown it's a Miracle drug Intakes will form Ice on them. but it's best to run it empty to store the car because of hydration.

I am most likely switching when I dyno tune my recently boosted track rat. E85 is fairly abundant in San Diego too. Being that it's just a track car it's not a big deal to go a little out of my way once a month to fill up a 5 gallon jug.

Damn I just realized I should have blamed ethenol's water attracting abilities on my Dad's liquor getting watered down.

HappyAndy wrote:

Huckleberry wrote: OK, OK, OK... I get it. It's time to quit. You don't have to call me out in public like this.

No, he's saying you need 25% more.

I'll drink to that! Er... or something....

Around here they price E-85 at about $.10 a gallon less than 87 octane. I think they are just trying to trick you into thinking it is 87 at that price.

I would look hard into the claims about more HP. It might be an anomaly with the Miata, but in general, ethanol produces about 20% less peak cylinder pressure. After all, its BTU content is considerably less than gasoline.

Ethanol makes less power and the greater consumption/cheaper price is usually about a wash. Where ethanol really shines is in a purpose-built engine with higher compression. But just putting ethanol in a regular gasoline engine is not a power-adder.

patgizz wrote: Real world: 2005 flex fuel avalanche 14.5 mpg on 87. 3mpg on e85. Yes, i burned 25 gallons in 75 miles. Stuck with regular 87 after that. The real question is how much power will it add to a v12 jaaaaaaag

As a counterpoint,

2014 Scion FRS

26-ish mpg on 93 octane

19-ish mpg on E85

And that's probably not a fair comparison because I did the muffler delete and the E85 tune at the same time, and I think I rev the motor out more now to hear the exhaust.

So, I go ~75% as far on a gallon of E85, but down here in Columbus a gallon of E85 costs ~75% as much. Essentially, the 10-15 go I get from the E85 are free horsepower.

Robbie wrote: This is relevant to my interests. Q: if I have a turbo car that is at (let's assume for easy discussion) the max power the turbo can provide on normal gas, do I stand to gain anything by switching to e85 (I know id need a crap ton more fuel capacity in pump and injectors) without changing turbo?

It very much depends on what is limiting the power in your gas engine.

If the power limit is due to knock limiting, you can gain a lot from that.

If the power limit is due to temperature issues- you can gain a lot from that.

If it's due to BOTH of the above (AKA, the turbo death spiral), you can gain a TON of power.

I'd look into e85 for boost related activities if the nearest station that carried it was less than 2 hours away.

comparison chart

This guy's math is biased, but there are valid points

Case study of one vehicle, but an actual test showing slower acceleration and increased fuel cost with E85

alfadriver wrote:

Robbie wrote: This is relevant to my interests. Q: if I have a turbo car that is at (let's assume for easy discussion) the max power the turbo can provide on normal gas, do I stand to gain anything by switching to e85 (I know id need a crap ton more fuel capacity in pump and injectors) without changing turbo?

It very much depends on what is limiting the power in your gas engine. If the power limit is due to knock limiting, you can gain a lot from that. If the power limit is due to temperature issues- you can gain a lot from that. If it's due to BOTH of the above (AKA, the turbo death spiral), you can gain a TON of power.

So what if the turbo is running out of 'size', meaning it is getting too far above and to the right of its efficiency range on the pressure ratio/cfm graph?

curtis73 wrote: I would look hard into the claims about more HP. It might be an anomaly with the Miata, but in general, ethanol produces about 20% less peak cylinder pressure. After all, its BTU content is considerably less than gasoline. Ethanol makes less power and the greater consumption/cheaper price is usually about a wash. Where ethanol really shines is in a purpose-built engine with higher compression. But just putting ethanol in a regular gasoline engine is not a power-adder.

Well, yes and no.

Gasoline has basically 43 MJ/kg of fuel, and is evenly mixed at 14.6:1. So for 1 kg of air, there's about 2.94 MJ of energy in the fuel that is required to burn that air.

Ethanol has 26.5 MJ/kg of fuel, and is evenly mixed in air at 9:1. Same 1kg of air, there will be about 2.94MJ of energy to burn in that air.

What you are seeing is that ethanol isn't fully able to extract that energy at stoich as it burns cooler, and the ideal physics are farther away than with gas.

Where it gets really interesting is a peak power. While I can't vouch for the source, a Hot Rod article (http://www.hotrod.com/articles/ccrp-0611-e85-ethanol-fuel-test/) suggests that peak power enrichment for E85 is 6.9:1 and gas is 12.5:1. The gas part is where I'm also familiar with, so the E85 seems good.

At that air fuel ratio, the 1kg of air now has 3.44 MJ of fuel energy for gasoline, and 3.84 MJ of energy for the E85. That kind of difference can easily make up for the physics burning difference.

(on the other hand- if you run the lean side of the enrichment- gas is 3.25MJ and E85 is 3.15 MJ- so the key of the key for E85 is that you can inject more fuel and have it make useful power)

Robbie wrote:

alfadriver wrote:

Robbie wrote: This is relevant to my interests. Q: if I have a turbo car that is at (let's assume for easy discussion) the max power the turbo can provide on normal gas, do I stand to gain anything by switching to e85 (I know id need a crap ton more fuel capacity in pump and injectors) without changing turbo?

It very much depends on what is limiting the power in your gas engine. If the power limit is due to knock limiting, you can gain a lot from that. If the power limit is due to temperature issues- you can gain a lot from that. If it's due to BOTH of the above (AKA, the turbo death spiral), you can gain a TON of power.

So what if the turbo is running out of 'size', meaning it is getting too far above and to the right of its efficiency range on the pressure ratio/cfm graph?

What is the effect on the engine? Or how does the engine change how it's being operated?

In reply to Robbie:

One of the first things to happen when the turbo is too small for the job it's called upon to do. First is the air is compressed more, higher peak boost targets to meet power goals, etc. That creates heat and higher IATs the other the fuel tables will become more fun to tune as the difference in boost level will have a greater difference within relatively small rpm ranges and loads. And we haven't even gotten into the boost creep issues that will likely ensue without a massive wastegate and higher boost levels on an overworked turbo.

The good news is compressor wheel upgrades are easy and readily available for most applications these days.