Running E85

[shookie]

So im thinking about switching to e85. what all would i have to do to use it? im going to be hooking my auto tune up soon so what kind of a/f should i have?

[Bert]

I don't know the limitations of the fuel pump, fuel line & injectors. If they can move the required amount of fuel you might be ok.  E-85 may require 25% more fuel than pump gas.  Just a guess but A/F 7:1

[Krandall]

No idea what the afr should be. but I'd guess like bert probably around the 7-8:1 ratio.

just curious, how come the switch?

[Peelz]

cuz ethanol is Iowas new cash crop

[shookie]

I have herd good and bad things about it and I'm thinking it might be worth it. It's alot cheaper and I can ride to the gas station to fill up on it. From what I have read I'm going to need a bigger injector? Is there anyother mods I would need to do to be able to run it safely?

[Bert]

Your PCV is autotune? How does that work..... you set the A/F?

Preddy used to talk about it. Maybe he would know something.

There's a shop near Des Moines with a very knowlegable tuner.

[Bert]

Link
http://e85vehicles.com/e85/index.php?topic=750.0

[shookie]

thanks for the good read. Yeah i havent hooked up the auto tune yet but plan on doing that as soon as i get my head studs. I plan on making all my tables 30% more fuel but i still need to figure out the a/f. from what i have read there is a difference in the a/f reading for gas and e85?

[Mad Dog]

The O2 sensor reads O2, so there's no difference in the way it reads.  But the desired a/f ratio IS different, and therefore the "autotune" aspect and target will be different.

[preddy08]

cut and copied from every E-85 thread I read.


"I posted this deep in a BS thread and would like it to get more light that it did. For those of you that have access to this stuff give it a shot! Ethanol burns cooler which is great and all, but when you toss some more timing to the mixture it becomes great!!

Hell at the least it is a cheap race gas (locally about 2.50). I would run up to a 13.5 compression piston with out any problems. I had my predator with 12.5 compression piston tuned for it (yes you HAVE to tune for it) and it ran amazing!!! The exhaust smelled pretty cool. Kinda like vodka. I talked to my dyno guy and he said that you can have two maps made for your bike. One for gas, and the other for E-85 and switch maps on the PC3 on a handlebar mounted switch. If you ever have to run other fuels this would be great.


E85 is 105 Octane, and requires you to much much richer than gasoline.

Theres a few differences you'll have to note:

E85 has a lower energy content that gasoline. This means less power per gallon. 1 gallon of gasoline contains 114,132 BTU. 1 gallon on ethanol contains 76,000 BTU. 1 gallon of E85 has roughly 83,263 BTU. MOST E85 isn't a straight mix of ethanol/gasoline. Its 85% denatured alcohol (~95% ethanol, ~5% gasoline). Thats 27% less energy.

Another thing is the A/F ratios for E85. The Stoichiometric ratio of Gasoline is 14.7:1, while it makes max power around 12.5:1. E85 has a stoichiometric ratio of between 9.73:1 and 9.8:1 (based on pureness), while max power is made as rich as 7:1, although recommended around 8:1.

So, less power, and richer A/F mixtures? Not exactly. Consider the BTU/gallon vs. the A/F ratio required to run E85.

Compare the stiochiometric ratios of the two. Gasoline is 14.7:1, while E85 is 9.8:1. I think my math is a little off on this but thats 50% more fuel. 1.5 (150%) x 76,000 = 124,000 BTU. Thats slightly higher than the power produced by a gallon of gasoline. Now take the max power rich A/F ratio of gasoline and E85. Gasoline is 12.5:1, while E85 is about 7:1. Thats about 78.5% more fuel than gasoline. 1.785 (178.5%) x 76,000 ~ 148,000 BTU. Thats roughly 29% more power than gasoline!
What else does this mean? Just by switching from gasoline to E85 and adjusting it to the max power rich A/F ratio in your turbocharged engine, you could pick up roughly 15% power. Another thing to consider it the octane of E85. Its 105. Think about running 105 octane gasoline in your car with a 7:1 A/F ratio. Detonation? Probably none. This means you can severly raise boost or advance your spark for higher power and not have to worry about detonation.

Another thing to consider. E85 is about as cheap as 89 octane gasoline, which is even cheaper than the 93 most SRT guys run. The only downside is that you'll probably see roughly a 25% decrease in MPG if you adjust the A/F ratios to run at the stoichiometric ratio of the E85 (you still won't have to worry about detonation at this ratio). With the increasing gas prices and the ever decreasing ethanol prices (it IS a renewable resource), in the years to come it may become cheaper to run on E85 than gasoline. "

[Blair]

cuz ethanol is Iowas new cash crop

i thought that was METHanol

[selland74]

You'll need a bigger injector.  And by the time you figure in the extra fuel you'll burn, it may not be cheaper than gas.  unless of course you need it for higher octane purposes. thats why i run it. its much cheaper than race fuel. 

[crisco]

Anyone try running e85 with 14:1 compression? I'm assuming it won't work since the e85 is equivalent to 105 octane gas but thought i would ask anyway. I know it probably depends on head, cam, etc but looking for someones experience on the matter.

[Bert]

I did a quick search & think 12.1 comp is safe. Higher than that & fuel testing might be done to verify E-85 purity to avoid a melt down. Just what I turned up

A quick read from Hot Rod Magazine
http://www.hotrod.com/techarticles/hrdp_0801_e85_ethanol_alternative_fuel/index.html

[NHRAdragracer]

Anyone try running e85 with 14:1 compression? I'm assuming it won't work since the e85 is equivalent to 105 octane gas but thought i would ask anyway. I know it probably depends on head, cam, etc but looking for someones experience on the matter.

I run it in a 14.25:1 Raptor 727 build without issues. I do add 6 oz. of Kemco's tetraethyl lead additive per 5 gallons for a topend lube, but the additive doesn't change the octane level any significant amount at that level.