Author Topic: e85  (Read 3127 times)

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Offline jfrabat

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Re: e85
« Reply #15 on: May 09, 2008, 01:58:42 PM »
Another benefit to E85 is improved performance. 

What do you mean by "improved performance"?  I have heard that because e85 contains less calories than fuel, the "explosion" is less violent (which is why you get less mpg), and so there is less power from the engine...  Dont know, though, as I have never tried driving a car with e85.
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95yj4

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Re: e85
« Reply #16 on: May 09, 2008, 10:26:21 PM »
Yeah there is ethanol in "normal" gasoline, but at 10% its really not going to affect anything. With 85% ethanol you can run into problems on the fuel system. From what I have heard, cannot confirm it though, it tears apart normal injectors so they use stainless.
I can't see it having improved performance on a stock motor. Less BTU's and higher octane. Using higher octane then what the motor is designed for will burn slower and cooler, then the right octane.
To make up for these loses you would want to raise the compression and/or, like Bigchelis stated, advance the timing alot.
Sorry if it seemed like I was ranting or offending anyone, it was not meant in that way at all. I just absolutely hate the idea of ethanol as an alternative fuel.
So sorry once again if I offended anyone.

TrailsLessTaken

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Re: e85
« Reply #17 on: May 09, 2008, 10:52:45 PM »
I've done a lil research on the E85 cause my Sierra is a flex fuel. The E85 is 105 octane, so you will get more power from it, but in order for it to be a flex fuel GM has to lower the compression on the engine to be able to run both gas and E85.  If you raised the compression on the engine I cant remember how much but enough so you could run straight ethanol your mpg would go back up.  I found this on GM's website a while back but I can find it now. My truck on gas gets about 15-16 and switching to E85 it drops down to about 11-12, and if your hauling a trailer or doing interstate driving you gotta have almost all the E85 outta your tank or your mileage drops real quick.  Thats my $0.02 on it anyways

Offline chardrc

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Re: e85
« Reply #18 on: May 10, 2008, 09:31:16 AM »
how many times do we have to say it... higher octane doesn't necessarily mean more power... e85 still has less power per gallon so it wont give you more power...  do to wikipedia and read for yourself http://en.wikipedia.org/wiki/Octane_rating


The octane rating is a measure of the autoignition resistance of gasoline and other fuels used in spark-ignition internal combustion engines. It is a measure of anti-detonation of a gasoline or fuel.
It should be noted that octane rating does not relate to the energy content of the fuel (see heating value), nor the speed at which the flame initiated by the spark plug propagates across the cylinder. It is only a measure of the fuel's resistance to autoignition. It is for this reason that one highly branched form, or isomer, of octane (2,2,4-trimethylpentane) has (by definition) an octane rating of 100, whereas n-octane (see octane), which has a linear arrangement of the 8 carbon atoms, has an octane rating of -10, even though the two fuels have exactly the same chemical formula and virtually identical heating values and flame speeds.
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Offline oldjeep

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Re: e85
« Reply #19 on: May 10, 2008, 11:04:17 AM »
how many times do we have to say it... higher octane doesn't necessarily mean more power... e85 still has less power per gallon so it wont give you more power...  do to wikipedia and read for yourself http://en.wikipedia.org/wiki/Octane_rating


The octane rating is a measure of the autoignition resistance of gasoline and other fuels used in spark-ignition internal combustion engines. It is a measure of anti-detonation of a gasoline or fuel.
It should be noted that octane rating does not relate to the energy content of the fuel (see heating value), nor the speed at which the flame initiated by the spark plug propagates across the cylinder. It is only a measure of the fuel's resistance to autoignition. It is for this reason that one highly branched form, or isomer, of octane (2,2,4-trimethylpentane) has (by definition) an octane rating of 100, whereas n-octane (see octane), which has a linear arrangement of the 8 carbon atoms, has an octane rating of -10, even though the two fuels have exactly the same chemical formula and virtually identical heating values and flame speeds.

Question is do you understand what you just posted?  While higher octane does not mean more energy, what it does mean is that you can run higher compression which does mean more horse power.    What trail less taken was saying was that flex fuel vehicles don't take advantage of the higher octane of E85 because their compression still ahs to be low enough to run pump gas.  So with a flex fuel vehicle you get the worst of both worlds when running on E85 - low fuel milage and low horsepower.  If they built the engine to run only on E85 you would get low milage and high horsepower - like my buddys E95 powered 502 drag car ;)
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Offline chardrc

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Re: e85
« Reply #20 on: May 10, 2008, 05:44:24 PM »
ya you have to have your motor set up specifically for it or it isn't worth it...
1990 YJ 4cly, ax5, 2.5 inch BDS lift, 31 MTr\'s,  Powertrax-lockers all around, track-bars removed, boomerang shackles, warn m8000 winch, electric fan. [sold but not forgotten]

2007 jk Rubicon 2dr

tttppp54

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Re: e85
« Reply #21 on: May 13, 2008, 02:20:50 PM »
ince your are sopposed to run a higher octane in boosted engine to help with detonation would e85 be a good idea to run?

Offline oldjeep

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Re: e85
« Reply #22 on: May 13, 2008, 02:55:55 PM »
ince your are sopposed to run a higher octane in boosted engine to help with detonation would e85 be a good idea to run?

As long as you can provide the additional volume needed.  The ricer crowd up here uses a lot of e85, but there is a consistancy problem.  E85 is between 70 and 85% ethanol which is a pretty wide range.
Chuck P
The clowns'? Oh, yeah, the clowns. We fight them too — entire armies, spilling out of Volkswagons. We do our best to fight them off, but they keep sending 'em in!
94 YJ - gone
98 ZJ - sons truck
97 TJ - daughters project

www.oldjeep.com