Coverting to e85 ethanol?

thoen · 01-14-2009, 07:16 AM

has anyone done this? using e85 ethanol in their 944? what would be needed for the conversion?

krystar · 01-14-2009, 08:53 AM

u'd need bigger injectors and a fuel management system like megasquirt. up fuel by about 30% and start tuning from there.

would be also a good time to redo the fuel supply system.

why do u want to do it? it provides no benefit for a NA car unless yer built to crazy specs.

thoen · 01-14-2009, 11:56 AM

less co2 pollution !

krystar · 01-14-2009, 01:20 PM

if you're trying to be green...you better reconsider. the production of corn based ethanol hasn't been proven to be any greener than the production of gasoline.

if you're trying to be green, biodiesel is where i'm putting my money.

thoen · 01-14-2009, 01:57 PM

ethanol does not produce co2 but i know what you mean. i am dipping into the green zone therefore i ask....

krystar · 01-14-2009, 03:12 PM

burning ethanol still produces CO2. it's not magic fuel. ethanol is still a hydrocarbon

C2H5OH(g) + 3 O2(g) → 2 CO2(g) + 3 H2O(l)

Rogue_Ant · 01-14-2009, 03:56 PM

There is a few of us who have converted to E85...
What exactly are you looking to know?

-Rogue

thoen · 01-14-2009, 04:56 PM

i want to know what we lose by converting and what we gain and how to do the conversion. i was watching the science channel nd the program stated that ethanol from corn or from whatever, does not produce co2. it does not produce carbon molecules from the alcohol in the convertion. i might be wrong but that is what i understood. the latest ethanols can be made from any vegetable by product such as the corn husks and i know we are all headed in the green direction and away from fossils. i want to head my 944 in that direction. it will never be a muscle car but it can be a great and beautiful cleaner machine.
thanks,
ernest

Mask of Destiny · 01-14-2009, 06:43 PM

Burning ethanol prodcues CO2; however, the plants that the ethanol is made of take just as much C02 out of the air so in theory ethanol is a so called "carbon neutral" fuel. Gasoline is made from hydrocarbons that have been in the ground for a long time. Burning it effectively takes carbon that was in the ground and puts it into the atmosphere in the form of CO2 (and CO).

Unfortunately, ethanol in the US isn't very clean as it's currently being made from corn. The energy yielded from the corn isn't a lot higher than the energy consumed in growing it (tractors, irrigation, etc.). Things will get somewhat better once they start using the entire plant (the tech is there, but I don't believe it's being used yet), but we would probably be better off with ethanol made from switchgrass. Too bad the corn industry has such a huge lobby.

Rogue_Ant · 01-14-2009, 11:17 PM

Yep burning E85 does produce CO2... in fact tail-pipe emissions are fairly similar to regular gasoline.

The main thing you lose when converting is going to be fuel-mileage. Expect a ~15-25% hit in fuel economy. This is dependent on how tuned you are for E85.
However E85 has a higher potential for power then pump gas, but unless you are running forced induction, or very high static compression (13-1 or so), then you will not be able to reap the potential benefits.

To convert to E85, you will want to make sure that the rubber fuel lines are new, or are relatively new. Now you will need a way of adding ~25% more fuel. This can be accomplished as simple as using an adjustable fuel pressure regulator and running ~4bar of fuel pressure. A more proper way will be with larger injectors and a chip designed with E85 in mind. This is the suggested way, as E85 has a different burn rate (slower) then gasoline and as such needs ignition timing to be adjusted (advanced).

-Rogue

ideola · ideola's Garage

It's a bit more complicated than that. For starters, E85 is not always the same mixture. Due to cold starting issues, during the winter most E85 is actually a 70-30 blend of ethanol-gasoline, but can vary anywhere between 70-85% at any time depending on the supplier and whatever formulation they happen to be running. Consequently, for proper tuning, you really should be running and ECU that is capable of taking input from an E85 sensor, which tells the computer how much ethanol is in your tank at any given time, and adjusts mixture accordingly.

For converting your system over, the proper thing to do is to change to either stainless steel or anodized aluminum. Ethanol will cause the plastic tanks to deteriorate faster (they're already prone to cracking) and it will cause the steel ones to rust faster from the inside out. You will also need larger injectors that can accommodate additional fuel flow and duty cycle, plus you will need to remove the in-tank pump, and install an external pump that is capable of delivering an additional 30% fuel flow. Standard rubber hoses and o-rings must be changed. In conversations with a researcher at Shell over in the UK, he mentioned to me that they are having significant problems even with Viton o-rings, which swell, crack and fail after relatively brief periods of exposure to E85. The answer seems to be perfluoroelastomer o-rings, which are made by both Staubli and Kalrez. But they are not cheap...pricing at mcmaster.com indicates that a single Kalrez o-ring is in the range of $30. Finally, any aluminum in the fueling system, such as the fuel rail, FPR, etc. should all be anodized or otherwise treated. Now factor in the 70-80% reduction in fuel economy due to the difference of energy stored in a gallon of E85 vs. conventional gasoline.

To summarize:

If you're considering converting for economic reasons, my estimates indicate that your return on investment will be something like 10 years. By the time you factor in the hundreds of dollars you'll spend to do a proper conversion, plus the difference in fuel economy, it is doubtful you will save much money.
If you're considering converting for ecological reasons, while there is evidence that E85 produces much lower emissions, as a previous poster pointed out, it is arguable that E85 does anything beneficial for the environment when considering the fossil fuels that must be burned to produce it, plus the terrible effects of all-corn crops on our soils. (ASIDE: there are many other crops that have a much better yield than corn, but you have to remember that E85 is government subsidized primarily through the efforts of the corn lobby, which does not want other crops to be used).
Notwithstanding all of the above, in my opinion, E85 is an awesome solution for high performance situations, i.e. high boost, high compression engines can realize significant benefits in terms of timing advance, cleaner burning, cooler burning, etc. But the economic and ecologic benefits don't apply in a high performance application!

Recommended Reading:
http://forums.rennlist.com/rennforums/928-forum/417988-the-official-e85-fuel-conversion-thread.html
http://www.924board.org/viewtopic.php?p=239224#239224
http://www.924board.org/viewtopic.php?t=26946
http://www.924board.org/viewtopic.php?t=28007
http://www.924board.org/viewtopic.php?p=218949#218949
http://afdc.energy.gov/afdc/e85toolkit/specs.html
http://en.wikipedia.org/wiki/E85_in_standard_engines

KitCarlsonEMS · 01-15-2009, 07:12 AM

The last three posts are great information. Much of the "green" movement has been pushed by poorly educated politicians.

Engineers need credentials. Politicians do not. It would be a different world today, if the "Al Gores" have a genuine understanding of chemistry, physics, and engineering.

The sad part is where the tax $$$ are being spent on unrealistic solutions to our energy situation.

It is important that the educated, write their congressmen and assist where possible in the current "global warming ...green movement".

thoen · 01-15-2009, 08:46 AM

all i can say is......................................thanks!!!!

KitCarlsonEMS · 01-15-2009, 09:05 AM

Not against you in any way.
You have a great heart, your intentions are sincere

It is about those preaching false science to reap profits!

blown 944 · 01-16-2009, 08:56 AM

I guess I would rather try to move in another direction rather than stay with the status Quo.

Really when everyone continues to speak negatively of ethanol it will be harder and harder to get people to convert, which will kill the demand and the potential to change to a better source.

I like it, and the corrosive behaviors are completely blown out of proportion.

How long would be required to judge what it does to a 944 fuel system?? I have seen no ill effects and have been running it for ~4 years now. Previous to that I ran straight Ethanol for 5 or so years in other cars.

Anyone ever thought about the bias towards or against Ethanol and who is behind it?? Persoanlly I do my own judging so I can determine whether or not something works. Not just read websites.

It's not that hard to tune either...Please..... the latitude it has in regards to tuning is far greater than pump gas.

thoen · 01-16-2009, 02:57 PM

sid,
what did you do to convert? it e85 or ethanol 100%? where do you buy ethanol? i am in ny and am thinking of doing it 'cause it is more green than oil. tell me more or pm me?
ernest

krystar · 01-16-2009, 03:04 PM

u can buy denatured alcohol at any hardware stores. pretty expensive by the gallon though.

u'd have to buy in bulk by 55gal to make it anywhere near affordable for a gas tank fillup though.

KitCarlsonEMS · 01-16-2009, 07:40 PM

My experience with ethanol has not been good. Most regular gasoline today has about 10% ethanol. I have found small engines used in heavy duty application run too lean. I tried E85 by mistake once while traveling in the Midwest. I experienced poor performance, and a 15% decrease in MPG. I keep good records of miles and gallons used. I have also read my owners manuals. They suggest not to use gas containing ethanol.

I also buy animal feed and have found the prices have doubled in the last couple years. We also know how our grocery prices have increased. I also have relatives that farm for a living. The increase in fuel (diesel) prices, and production costs makes farming unprofitable. Even with the subsidies on the ethanol fuel, it is not an economical choice.

I would rather eat farm products made in the USA than imported products! Look what happened with imported (China) dog and cat food. It will take nearly 100% of US farm production to make ethanol to burn in autos. Take time and read you flour bag. It will say distributed by "xxxx" it may not say where processed or manufactured.