E85 Ethanol Gas

[PhreakV]

here is a relatively informative post about ethanol I found on another forum:

Ethanol can make slightly more power than gasoline even though it has a lower BTU/lb.

Ethanol 12,000 btu/lb
Gasoline 19,000 btu/lb

Ethanol Stoich ~9:1 In Lamba this equals 1
Gasoline Stoich ~14.7:1 In Lamba this equals 1

Say best power is at .89 lambda which is around 13.0:1 A/F ration in gasoline terms and 8:1 A/F in ethanol terms.

So even though ethanol has a lower btu per pound, we are using more of it per pound of air.

13(AF Ratio) / 8(AF ratio) = 1.625 ratio of ethanol to gasoline at the same lambda

12,000(ethanol BTU) X 1.625 = 19500 BTUs

( (19500 X 100) / 19000) - 100 = 2.63% potential power gain

If you do the math on methanol with it's 6.4:1 stoichiometric and ~9500-9800 btu/lb you get a gain or around 14-17%, which is a good reason to use methanol over ethanol on a race only car.

Ethanol and methanol also have a high latent heat of vaporation, in the 400s btu/lb compared to gasoline in the low 100s. So they both take a lot of heat to convert from liquid to vapor and inturn cool your intake charge temps and combustion chamber temps down a lot. I don't know how much this would help a naturally aspirated car, should help pick up a few HP. But on a boosted car it makes a world of difference, you can run 40-50psi of boost without an intercooler and a small radiator on a methanol car. The same car on a good race gas like VP C16 would have to run an intercooler and be limited to boost in the 30s.

When doing an E85 conversion though, you have to make sure your fuel tank, lines, fuel rails, injectors and regulator can handle the ethanol. And you need a pump, lines and injectors big enough to handle the extra flow requirements. Ethanol isn't anywhere near as corrosive as methanol, but it is still corrosive to a lot of things like aluminum and normal rubber fuel lines. You don't want it eating away part of your fuel tank or an aluminum fuel rail and clogging a fuel injector.

I would like to convert a DSM to E85 someday so that I could run 30psi daily on $1.75/gallon fuel.

 

[Delivery_Guy]

Hey Murph-

Any updates on this? How many miles...how's the car running? Any CEL's yet?

 

[igdrasil]

Another note, on some sites it states that Methanol has a 105 octane rating while on others it says between 120-135.

Is there any way we could find this info from a trusted source?

 

[Delivery_Guy]

Another note, on some sites it states that Methanol has a 105 octane rating while on others it says between 120-135.

Is there any way we could find this info from a trusted source?

http://www.e85fuel.com/e85101/faqs/e85.php

Bottom of the page it says 105 Octane.

 

[Delivery_Guy]

This is a good little blurb about the differences between a gasoline vehicle and a E85 one.

Most important is that ethanol is corrosive.

http://www.e85fuel.com/e85101/faqs/diffferences.php

 

[igdrasil]

http://www.e85fuel.com/e85101/faqs/e85.php

Bottom of the page it says 105 Octane.

Yeah, but what about pure methanol? The one used for drag racing? One gallon here is easy to get for $5.00. Then we could mix it in 10-20% with 93 octane and raise the octane rating between 97-100 octane.

I think E85 is a commercial standard mix lowered to 105

 

[mp3moose]

Yeah, I have seen this mix done and work on a regular basis.

 

[igdrasil]

This is from MAZDA 2003 VEHICLES, im sure it applies to all from 1990:

Gasoline blended with oxygenates such as alcohol or ether compounds are generally referred to as oxygenated fuels. The common gasoline blend that can be used with your vehicle is ethanol blended at no more than 10%. Gasoline containing alcohol, such as ethanol or methanol, may be marketed under the name Gasohol.
Vehicle damage and drivability problems resulting from the use of the following may not be covered by the Mazda warranty. Gasohol containing more than 10% ethanol. Gasoline or gasohol containing methanol. Leaded fuel or leaded gasohol.

 

[RallyeRedSi]

suscribing

 

[Delivery_Guy]

Yeah, but what about pure methanol? The one used for drag racing? One gallon here is easy to get for $5.00. Then we could mix it in 10-20% with 93 octane and raise the octane rating between 97-100 octane.

I think E85 is a commercial standard mix lowered to 105

Sorry, I misread your post. But yeah, your other post makes sense...I think methanol is more corrosive than ethanol.

 

[orphman]

any east coast supplier of this .. PA area?!!?

 

[murph1379]

I think the octane differences come from pure ethanol vs. E85, which is only 85% Ethanol.

I'm also pretty sure that Mazda's warranty statement has more to do with covering the bare minimum they can get away with than with the scientific risk level involved. I'll be interested to see what they say when MN mandates 20% Ethanol.

230ish miles, car runs like a dream, no CEL, but I only used 1/4 tank Ethanol. I'm getting slightly lower gas mileage than usual, but part of that is that I can't stay off the accelerator, it's just too much fun. =]

Joe - I don't think you usually get out this far, but the Holiday on Hwy 12 in Long Lake has E85.

 

[PhreakV]

its my understanding that you burn more of it simply because the nature of the ethanol requires more of it to be burned (lower a/fs to reach optimal levels). your ecu is prolly trying to compensate by dumping more fuel without recognizing it as e85...

 

[Stormtrooper77]

Your mileage definitely decreases with ethanol blended gases because it does burn quicker.

 

[Delivery_Guy]

Luckily, there is a Holiday on 7 by my work that has it too.

[ThreadJack]
You make it up to St Cloud today?
[/ThreadJack]

 

[murph1379]

St Cloud? You mean down to Treasure Island?

I won a trophy in St Cloud two months ago, but I didn't go anywhere on sunday.

 

[Delivery_Guy]

St Cloud? You mean down to Treasure Island?

I won a trophy in St Cloud two months ago, but I didn't go anywhere on sunday.

Had my days all criss-crossed. St. Cloud is this Saturday...but I won't be there either

Glad to hear you are winning.

E-85 still rocking?

 

[murph1379]

Awww I wish I could make it on saturday...

E85 still rocks, I don't feel like testing the waters at more than 25% blend, but this is plenty of improvement for me. =]

Have you tried it yet?

 

[Delivery_Guy]

Awww I wish I could make it on saturday...

E85 still rocks, I don't feel like testing the waters at more than 25% blend, but this is plenty of improvement for me. =]

Have you tried it yet?

No, I'm a little worried about melting something. You wanna let me know how things are going in a year, lol.

 

[murph1379]

what's to worry about, it's just yer fuel system! =]

Oh yeah, it's 95 degrees today... is your car bogging? Mine isn't. =]