MacGuffin

I believe that the 30% you found is the difference in btu/gallon; i.e., there is about 30% less energy is a gallon of ethanol compared to a gallon of gasoline. Fuel economy depends on more than just btu/gallon. You also need to look at how many of the btus of fuel you are pumping into the engine are coming out as useful work. For several synergistic reasons, ethanol is a more efficient fuel in a turbocharged engine than is gasoline. In a well-designed engine, that efficiency advantage largely makes up for the disadvantage in the energy density of ethanol.

sentry65

iTrader: (11)

I wouldn't see a reason to use meth injection anymore, that's why I'd do straight water injection.

meth is 107 octane
if E85 is already 104-105 octane, what's the point of adding meth?
I'd just use straight water and lower the intake temps

DMK

iTrader: (6)

I believe Meth also has cooling abilities. I touched a intake manifold with straight meth injection after a 30 min run and it was still cool.

abyss

a local honda shop was testing E85 on one of their customers NA cars that usually runs 110 octane and when dynoing with E85 it made 10hp more and shaved .4 off his 1/4 time that night. Wonder if it would have similar gains on a boosted motor?

MacGuffin

Usually you can get larger gains with boosted E85 than with NA E85. In a NA engine, E85 lets you do two things to improve performance: 1) increase compression ratio; 2) change timing. Changing timing is easy to do. Changing CR, not so much. In a boosted engine you also have the option to increase boost, which is also usually easy to do. Using a different EMS map to select more boost when running E85 also means that boosted engines make even better flex fuel powerplants (able to run either gasoline or E85) than do NA engines.

The gains over 110 octane gasoline are smaller than over lower octane gas; but even so, you should still see more gain in a boosted application than NA.

sentry65

iTrader: (11)

well we need to figure out how you go about converting to E85. I've heard it's around a $400 process, but those are usually normal economy cars, not high performance cars.
There seems to be at least one E85 gas station in every major city. I can only see the numbers increasing over time.

there will probably be a learning curve for tuning and limits on the stock engine with E85 etc

MacGuffin

Half right. There are quite a few E85 stations, and their numbers are increasing; but there isn't yet one in every major city.

Audible Mayhem

iTrader: (48)

finally a great topic!! if i lift my heads on this new project then we are switching over to alcohol. OR if i get bored with C16 ...


lots of power to gain but not practical for any kind of street car. flushing out the fuel system every time you stop driving the car would suck.

also having to run at a 5.4 to 1 AFR could add up nicely !!!

MacGuffin

On the contrary, E85 can be very practical if there are pumps near you. If you are willing to run a still and have a source of cheap feedstock, then neat ethanol can also be very practical and cheap. You don't need to flush ethanol, since it is not nearly as hard on the fuel system as is methanol.

Stoich AFR for E85 is about 9.8, and you will likely run very close to that even at max power.

InjectedPerf

iTrader: (15)

You could always switch to VP Import

go-fast

have you checked into the hoops you have to jump through to operate a still?the requirements are overwelming as most people dont have there own farms.i ran e85 last winter and i can tell you fuel economy sucks first hand.saab's best case cenario and all the pro e85 propaganda you can muster can not argue with my gas gauge.like saab if you build a high compression motor and detune it to still run on gas of course the specs will be in e85's corner but in the real world the value is a wash.as far as pumps being available we were ordering tankers from out of state to supply our needs and have seen no growth of availability since.i love the idea of alcohol to power turbo z's ,there is definitaly hp waiting for us with the higher compression ratio's we could run ,but when your goal is hp w/economy alcohol is a big loser.

abyss

I'm gonna keep doing research on the E85 and keep in touch with the shop near my house and see if I can get some dyno sheets from them. I have a gas station 5 minutes from my house that sells E85 for $2.54 a gallon...soo if I can find what I need to do to my truck to make it safe I might look into it on there to play around with.

MacGuffin

Sure, I've looked at what it takes to run a still. There are some regulatory hurdles to get over, and it does take some time and effort, but for some people it is well worth it. You don't need a farm to make your own ethanol, but neither can you run a still in an apartment. If anyone is interested in the details, they are readily available.

As for fuel economy, it is not going to be as good as gasoline if you just run your gas engine on ethanol. At the same time, though, you'll likely be making a good bit more power. On the other hand, if you build a smaller displacement, higher compression, higher boost engine to make the same horsepower and torque that you were with a larger gasoline engine, then you can get comparable volumetric fuel efficiency. There are simply too many options for trading off power, fuel economy, and fuel flexibility when building an engine to run on ethanol to make simple, blanket statements like "you will have to burn 42% more fuel."

go-fast

so how many acres of property do you need to get a distillers permit?also if you build an engine to maximize alcohol economy you lose all the cost savings of the cheaper fuel.i'm not saying it wont work,i'm saying it's not practical to look at it from a cost saving perspective.i bet whoever builds a alky turbo z will be king of the hill until someone builds a better alky turbo z!wich was my point all along before we misdirected to the 47 mpg stuff.

MacGuffin

I don't believe there is any acreage requirement for a Small Alcohol Fuel Producer permit.

go-fast

i'd have to dig for paperwork but i believe it was three acres with an additional setback dependent on nearest residential dwelling,so if your house was in the middle of 3 acres you could not qualify.now this is all governed by the atf....good luck.

Q45tech

The reason E85 is 15% gasoline is so the engine can start in cool [<50F]temperatures study vaporization points of different fuels.