E-85 and how to use it effectively.

[ErikW]

If you have incite to your experience on E-85. Please comment on your experience with this so far. Also what was necessary to replace or modify your car and tune it, to use E-85?
What limited info I've learned about may be incorrect, but it's what I got so far. So please comment on this...
__E-85 (85% ethanol, 15% gasoline) is about 70% slower burning and is about 100-105 octane rating. This requires a richer stoich. A 9:1 ratio. I think the specific gravity is different also. This may change the way you tune for it in other ways, as well.
__E-85 is a higher level of alcohol and can potentially burn cleaner. If it's tuned correctly, it can burn cooler/ more efficient. This is especially good for turbo'ed cars! Many turbo engine owners have reported lower EGT's. This can be a very good thing for everything in your engine. It may be a good thing for your exhaust gas, into the turbine, for a better spool.
__Since E-85 is an alcohol, this can dry out and wear certain car parts. The general consensus that I have grouped is: the fuel pump, lines, certain gasket materials, and fuel rails that are aluminum without any coating inside can cause corrosion and degradation. There may be other ramifications long term as well. But I'm not aware of them.
__ Automobiles manufactured after 1988 in America started to make fuel system parts more corrosive resistant. Ethanol has been in our existing gas for years to help reduce emissions. I've noticed that up to 10-15% is mixed with the gas we use and is used more during the winter seasons for this reason.
__The ECU and O2 sensor is likely not compatible unless you have an alternative fuel car pre-designed from the factory. So our older DSM cars need to be "updated" and modified to allow relatively safe operation. Such upgrades include air/fuel control (like a DSMLink) and a WB O2. The narrow band O2s may not read your mixtures correctly so I've also read that certain WB sensors can read a "correct" mix. Apparently the ones that read in "lambda" will read a more accurate value. So when you are tuning for perfect stoich., you are actually tuning still at a 14.7:1 ratio for E-85.
I'm only guessing that if people are tuning with any other O2 sensor that is not read in Lambda, that they need to tune with a 9:1 ratio?
I've also read that for our cars we need to adjust the fuel injector pulse width to accommodate for this difference as well.

__q.1__ Since the stock pump will not hold up. Is an aftermarket pump like a Aeromotive brand compatible?? I'd think since if they are for race applications, more race cars are using this fuel as well. Unless there is a certain model only better suited for this, I don't know.
__q.2__ Is our stock fuel lines ok? There is a coating on them and the material is very hard to crack or break. So I'm guessing that this is not of a metal like aluminum that can degrade with this fuel.
__q.3__ Are there any other gaskets and O rings that are needed to be replaced to prevent incompatibility?
__q.4__ The SS braided AN lines are widely used in the racing world. Although it's a rubber line with SS reinforcement, I wonder if this is also a concern for degradation?
__q.5__ The stock fuel rail is all aluminum. So this would have to be replaced or coated. IF it's replaced, what would be a proper replacement? Or is there a cheaper solution to coat it?
__q.6__ What are the best parameters for tuning that people found with DSM Link and a Lambda type WB (like my Tech Edge brand)?

[Carl Morris]

If you have incite to your experience on E-85. Please comment on your experience with this so far. Also what was necessary to replace or modify your car and tune it, to use E-85?
What limited info I've learned about this so far may be incorrect, but it's what I got so far. So please comment on this...
__E-85 (85% ethanol, 15% gasoline) is about 70% slower burning and is about 100-105 octane rating. This requires a richer stoich. A 9:1 ratio. I think the specific gravity is different also. This may change the way you tune for it in other ways, as well.


I don't think it's much slower burning, the timing requirements for max torque are not supposed to be significantly different than on gasoline if already tuned for ideal gasoline timing. If gasoline tune is significantly retarded due to octane issues, then yeah, you'll be able to add that timing back in on the E85. It is a bit heavier than gasoline, as I recall. The 9:1 stoich is correct for pure ethanol. For E85 it's closer to 9.8:1.


__E-85 is a higher level of alcohol and can potentially burn cleaner. If it's tuned correctly, it can burn cooler/ more efficient. This is especially good for turbo'ed cars! Many turbo engine owners have reported lower EGT's. This can be a very good thing for everything in your engine. It may be a good thing for your exhaust gas, into the turbine, for a better spool.


I believe that is all true, except I'm not sure about the better spool. With lower EGTs, spool may be affected negatively. I haven't noticed anything one way or the other in that area.


__Since E-85 is an alcohol, this can dry out and wear certain car parts. The general consensus that I have grouped is: the fuel pump, lines, certain gasket materials, and fuel rails that are aluminum without any coating inside can cause corrosion and degradation. There may be other ramifications long term as well. But I'm not aware of them.


People exaggerate this. There have been OBD-II people running straight E85 for years with no issues (WRXs). Having said that, after several months of running about 30-40% E85 I had to clean my aftermarket fuel filter for the first time ever. It had a thin layer of slimy goop on it that might be normal after that much time and fuel or might not. Us early 90s people may have issues if we don't clean fuel filters regularly. We'll see how soon I have to do it again.


__The ECU and O2 sensor is likely not compatible unless you have an alternative fuel car pre-designed from the factory. So our older DSM cars need to be "updated" and modified to allow relatively safe operation. Such upgrades include air/fuel control (like a DSMLink) and a WB O2. The narrow band O2s may not read your mixtures correctly so I've also read that certain WB sensors can read a "correct" mix. Apparently the ones that read in "lambda" will read a more accurate value. So when you are tuning for perfect stoich., you are actually tuning still at a 14.7:1 ratio for E-85.


If I'm understanding you, I don't believe you are correct. The factory O2 sensor will detect stoich just fine on ethanol/gasoline mixtures. Depending on the mixture, this will no longer be 14.7:1, but that doesn't matter to us. If you want it to run exactly like it does on straight gasoline, and are willing to run straight E85 all the time, "conversion" could be as simple as putting in fuel injectors that are 14.7/9.8 = 1.5 = 50% bigger. This will give you exactly the same air fuel ratios as you were running before, if you think in terms of Lambda. If you are running a wideband that reports in gasoline A/F ratios, just aim for the same reported air fuel ratio as you would run on 100+ octane gasoline. Sure, you're being lied to about the actual ratio of air mass to fuel mass, but the Lambda number is the same and that's what you really care about.


I'm only guessing that if people are tuning with any other O2 sensor that is not read in Lambda, that they need to tune with a 9:1 ratio?


No, because the sensor thinks in Lambda and assumes you are running gasoline when reporting gasoline-style A/F ratio numbers. The fact that you are running other fuel just means that the constant that the sensor interface is multiplying by in order to report gasoline numbers is wrong. If you like 11:1 on your wideband display with 100 octane gasoline, you'll like 11:1 on your wideband display with E85.


I've also read that for our cars we need to adjust the fuel injector pulse width to accommodate for this difference as well.


Only if you are trying to run the same injectors that you ran on gasoline. In that case you'll need to add 50% to keep everything exactly the same. Most people prefer to run leaner on E85, though, and only add about 30%. On my 30-40% mixture I only add about 15%.


__q.1__ Since the stock pump will not hold up. Is an aftermarket pump like a Aeromotive brand compatible?? I'd think since if they are for race applications, more race cars are using this fuel as well. Unless there is a certain model only better suited for this, I don't know.


On an Aeromotive you'd be fine, but what makes you think the stock pump won't hold up? I think a much bigger concerns is that the pump you currently run won't be able to KEEP up with the higher flow requirements.


__q.2__ Is our stock fuel lines ok? There is a coating on them and the material is very hard to crack or break. So I'm guessing that this is not of a metal like aluminum that can degrade with this fuel.


It's fine for a while. Will it be fine for the life of the car? Don't know.


__q.3__ Are there any other gaskets and O rings that are needed to be replaced to prevent incompatibility?


If you're paranoid and/or a perfectionist, you'd replace everything that you fuel touches with parts designed for alcohol use. Otherwise don't replace anything and just pay attention to filters and fuel pressure...tons of people are doing that successfully. If you're going to make big power, though, you'll probably want to go the "replace everything" route, because you'll need a ton of flow.


__q.4__ The SS braided AN lines are widely used in the racing world. Although it's a rubber line with SS reinforcement, I wonder if this is also a concern for degradation?


Is it sold as being alcohol safe? If not, it's probably no better than the stock stuff, and could be worse.


__q.5__ The stock fuel rail is all aluminum. So this would have to be replaced or coated. IF it's replaced, what would be a proper replacement? Or is there a cheaper solution to coat it?


That would be the last thing I would stress about, but if I was going to stress about it I'd find out what methanol people like Shep were doing.


__q.6__ What are the best parameters for tuning that people found with DSM Link and a Lambda type WB (like my Tech Edge brand)?

Personally I'd just have the WB report using gasoline numbers same as always, and I'd tune for the same values as I'd use with 100 octane gasoline. Alcohol does like being rich compared to race gasoline, so I wouldn't go nuts leaning it out. Probably 12:1 at the leanest? You're unlikely to break the motor going lean with alcohol, it just makes good power set up rich. For that reason I'd probably run something more like 11:1 using gasoline-style reporting from the wideband. Or, put it on Lambda and look for 11/14.7 = 0.75. Same difference...

[ErikW]

Thanks much.
I'm not familliar with Lambda. All I was aware of is that this may affect how you read the WB. Is there a setting then when you said to 'put it on Lambda" in your last paragraph? Can you explain your last paragraph more, please. Us laypeople may not understand this part as well.
I think you mean 11:1 is being for wide open throttle (wot) but what do we do for the rest of the powerband and throttle?
If I richen it up. could I just bring up (or down?) the global settings on the DSM Link for full rpm fuel control? Basically speaking, would that be a good place to start?
thank you.

[Carl Morris]

Lambda is the number you get if you divide the actual air/fuel ratio by the stoichiometric air/fuel ratio. For example, if you are running 11:1 on gasoline, you are at 11/14.7 = 0.75 Lambda. When I say "put it on Lambda" I am assuming that you have a wide band that can be set to report at least two different ways, Lambda or gasoline A/F. If you have it set to gasoline, it's just going to report Lambda * 14.7.

Lets say you have it set to gasoline (or that's the only way it's capable of displaying). But lets say you're actually running straight E85 at an actual A/F of 7.35. The sensor itself will report whatever voltage is associated with a Lambda of 7.35/9.8 = 0.75...and the display will report that as 11:1. So my point in all of this was that if you want to (or have no choice but to) use gasoline numbers, no big deal...tune for the numbers you know you'd want if you were running 100 octane gasoline.

For your non-WOT settings you'd be expecting to see ~14.7 on the display, and that's what you'll see with the E85 as well when in closed loop. It's a lie, but you don't care, because it's actually telling you what you want to know.

The place to start is to put in 50% bigger injectors or add 50% more fuel with the sliders, assuming you just put straight E85 in it. You should see A/F numbers on the wideband that look just like they did before with the gasoline and less fuel. If you don't because your fuel system won't flow that much, spend money until it will or give up on running straight E85. If you want to lean it out now because the only reason you ran that rich before was to deal with detonation, go ahead, but I'd continue to run a Lambda around 0.75, or a gasoline display of 11:1. So what I'm saying is globally crank up the fuel with control sliders or bigger injectors appropriate to the percentage of E85 you're using, and let the ECU tables and closed loop system continue to operate the same way they did before. In a factory ECU you'll know you've got it right when the fuel trims look the same way as they did before.

[Bryan Savage]

Just to clarify...

The energy density of gasoline (C8H18) is 4.4 x 10^7 J/kg.

The energy density of Ethanol (C2H5OH) is 2.68 x 10^7 J/kg.

Therefore, in one kilogram of E10, there are 4.228 x 10^7 J of energy.

In one kilogram of E85, there are 2.938 x 10^7 J of energy.

This means that E85 has seventy percent as much energy per unit volume as E10. This is why you must burn much more E85 to attain like-performance as E10. If you must burn thirty percent more fuel, your fuel mileage will also decrease by thirty percent. That's what the good people at GM fail to mention when they tout their Flexible Fuel Vehicles. I am aware that as far as performance goes, many swear by, or are experimenting with, E85, and thusly, fuel economy isn't very important; but those who are thinking of running it in a daily-driver well, that's quite a sizeable hit to the purse/wallet. E85 is not the cure-all of fuels. If you're running it because you're also trying to run 275 kPa of boost and you've exhausted all other options, then go right ahead. However, if you're trying to use E85 so you can try to hold 172 kPa on your 14B with no other modifications save for a hacked MAS, then maybe you shouldn't be worrying about your fuels just yet.:)

[Carl Morris]

I am aware that as far as performance goes, many swear by, or are experimenting with, E85, and thusly, fuel economy isn't very important; but those who are thinking of running it in a daily-driver well, that's quite a sizeable hit to the purse/wallet.

Not so much at $1.99 per gallon. At that price I'm actually saving a tiny bit of money compared to 91 octane. But yes, if you're paying the same price for it as gasoline, you're taking a financial hit because you will burn 30-50% more of it.

[Bryan Savage]

Well, here in Fort Collins, there isn't any place that sells E85 yet, so it's not worth it to try and do anything up here anyway!

[ErikW]

just for cross reference... This thread (http://www.codsm.org/forums/showthread.php?t=347) on calculations for pump gas for injector size is also something to think about. The formula could be a rough basis on how much more is needed for Ethanol.

[Carl Morris]

There have been OBD-II people running straight E85 for years with no issues (WRXs). Having said that, after several months of running about 30-40% E85 I had to clean my aftermarket fuel filter for the first time ever. It had a thin layer of slimy goop on it that might be normal after that much time and fuel or might not. Us early 90s people may have issues if we don't clean fuel filters regularly. We'll see how soon I have to do it again.

Update on this: I was down about 20hp when I finally made it to the track a month or so ago, so I've been trying to do all the maintenance that I'd been slacking on for a couple of years and see if that helped. The K&N was filthy (we're talking caked on gunk...my filter is low behind the fog light), and I did have a pretty healthy boost leak at the ISC and some lesser leaks at the IC pipe connections. I took the fuel filter filter back apart and it's been about a month after the previous cleaning. It was totally clean, so that at least adds to the plausibility of my previous clogging being due to 3+ years of normal accumulation rather than 6 months of 25-30% E85. The car is feeling good, but I can't get it to hold more than 23psi at redline. The 25-26 psi in the midrange on 2/3 91 = 1/3 E85 feels good :-). I don't have any knock, but even I am starting to feel a bit cautious for the stock bottom end above that. I'm hoping to get to the track one more time before they close just to see if I got the missing power back.

[Bryan Savage]

Hey y'all. I haven't been on here in a while because of school, but I just thought people might want to know that right across from where I live, at Shields and Drake in Fort Collins, there used to be a Diamond Shamrock petrol station.

Recently it has closed down. But today, I see there's another fuel station going in and there's a listing for E-85 on their signboard. So it looks like The FTC is finally going to get an ethanol station.

Just thought everybody might like to know. When it opens, I'd be happy to keep the board up to date on the cost if anybody is interested.

[JackM]

Just a couple more things:

I converted my daily driver 5 cylinder SHO to run on E85. All I did was mod the MAF sensor to read 33% richer. It runs fine and has all the stock O2s and original ECU.

Be careful when running a lot of power and selecting the right fuel pump. My brother and I found the Aeromotive A1000 fuel pump wasn't enough for E85 with our power range. We had to go with the 2000hp rated Magnafuel pumps to make sure we had enough fuel. I am also noticing my 1600cc injectors are working pretty hard. I believe I have around 80% duty cycle the last time I logged, and the car wasn't even close to running at max turbo boost/efficiency yet. My brother is probably going to go up to 1800-1850cc range, because he is thinking of nitrous in the near future.

Yes, the engine stays a lot cleaner. My brother just changed his oil the other day with 3k miles on it, and it still looked brand new and clean. His plugs still looked new too with no garbage on them.

Keep a close eye on junk from your fuel tank clogging up filters when you first convert over. My brother checked his pre-pump filter the other day, and it was clean. GVR4 with 220k miles, we thought it would be plugged up. I heard other people though having problems, so we have been keeping an eye on things and so far nothing from the tank is doing anything. My SHO has 360k miles, and all the original fuel system parts are fine too, and the filter is still okay on that car as well.

Oh, and one more thing. When running E85, keep a VERY close eye on your knock and WB. Down here, we get around E70-85 and never know until we run it. My brother had a scare the other day on a fill that had to be E70, because the car knocked real bad and showed very lean compared to his last tank. Now, on a new fill, everything is fine and appears to be back up around 85.

Jack

[sbiggi]

A Walbro 255 wont be enough to run E85 if you are moving ~42 lbs/min.
I burned up a valve.

Everything was fine, no knock, then out of no where 30+ counts and that was it. Burned the ground strap off before I could react and mesed up a valve.