Runn

MORE INFO IS COMMING! WORK IN PROGRESS





Soo you want to use E85? Iīm getting alot of question about E85 and i try to answer but i dont have the time to answer everybody. Soo i have put together some info for you... First the info you need and later a small howto.

There is tons of info about sparktiming and best AF to use with Gas but on E85 it is almost nothing, We have to work together here and share our experiences.


Be patient please, more info will be added

First of all, what is E85?:
E85 consists of 85% ethanol and 15% additives. The additives vary a lot depending on where you live and time of the year. But roughly, the 15% additives is mostly made up of gasoline, additives that helps the engine to make a complete burn, additives that helps the engine start when itīs cold and additives to color the fuel and the flame (so you know what substance it is, and also to help you see that it is really burning).


(Positive) facts about E85:
1. It is not corrosive to the fuel system or the engine. This is a myth and ethanol is often confused with methanol, which actually have corrosive properties. Iīve run my car for well over two years on E85 without a problem. Some models before 1988 on the other hand may have some parts that is not ethanol resistant. If we are talking Volvoīs, then this mainly applies to the non-electronically injection systems such as K-jet etc. Most cars with electronical fuel injection (EFI) should be resistant to ethanol. Some people say it would kill your engine right away and that you should buy there racefuel instead (of course they say )

2. It is not as harmful to the nature/environment as gasoline or any other petroleum products for that matter. Ethanol is made out of renewable energy resources such as crops and trees to name a few things. The carbon dioxide that an ethanol powered car emits is not contributing to the greenhouse effect, but is taken up by the plants and is being "re-used". The carbon dioxide then goes around in a closed loop. Gasoline on the other hand is made from oil that comes from old dinosaurs , plants and other stuff 100 000 of years ago, and it doesnīt take part in the closed loop but only adds to the amount of greenhouse gasses. Ethanol is also easily bio-degradeable if it should leak into our environment.

3. E85 is 104-105 octane and therefore itīs more knock-resistent and can tolerate more boost or a higher CR.

4. E85 cools the intake charge more and therefore itīs more knock-resistent and can tolerate more boost or a higher CR. And it also makes the engine run cooler and to some degree, even safer.

5. E85 is in most cases at least 5% more effícient than gasoline at the same lambda value (up to 25% more efficient on some cars optimized soley for E85). Mill your heads

6. Since E85 has very good cleaning properties as well as leaving behind a rest-product of water, it is cleaning the fuel system and it will keep the injectors nice and clean. The combustion chambers, valves, ports and the exhaust will also be clean(er), almost like the car had water injection.

7. In most cases it will cost less $/mile to run on E85.


(Negative) facts about E85:
1. Cars running on E85 have some trouble starting when the engine temperature drops below +5*C. Cars running E100 (not very common) have some trouble starting when the intake (the air) temperature is below +15*C. This is easily solved by using an engine heater in the winter, electrical or fuel-heated (this is recommended on all cars regardless of fuel to get better mileage, less wear on the engine and less impact on the environment etc., but that is another matter to discuss and will not be brought up here...). Some people also adds a little extra gasoline to the tank of E85 to help with cold-starts.

2. Since cars running E85 requires roughly 30% more fuel, a tank of E85 will not get you as far as a tank of gasoline and you will have to refuel more often. This is often disregarded by E85 users who learn to live with it because of the economical gains.


Technical facts about the mentioned fuels:
E85 requires 39% more fuel to reach stoich even if that is not what you may come up with when doing calculations based on the table below. This is because the injector flow is slightly different when using E85 among many other things I canīt really think of at this time (will be added at a later time).

Fuel ........................ AFRst ........ FARst ....... Equivalence Ratio ... Lambda
Gas stoich ................ 14.7 .......... 0.068 ................ 1 ................... 1
Gas max power rich .... 12.5 .......... 0.08 ................. 1.176 .............. 0.8503
Gas max power lean .... 13.23 ........ 0.0755 .............. 1.111 ............. 0.900
E85 stoich .................. 9.765 ....... 0.10235 ............ 1 ................... 1
E85 max power rich ...... 6.975 ....... 0.1434 .............. 1.40 ............... 0.7143
E85 max power lean ..... 8.4687 ...... 0.118 ............... 1.153 .............. 0.8673
E100 stoich ................ 9.0078 ...... 0.111 ............... 1 .................... 1
E100 max power rich .... 6.429 ........ 0.155 .............. 1.4 .................. 0.714
E100 max power lean .... 7.8 .... ...... 0.128 .............. 1.15 ................ 0.870

Ethanol reaches max torque at richer mixtures than gasoline will.
The term AFRst refers to the Air Fuel Ratio under stoichiometric, or ideal air fuel ratio mixture conditions. FARst refers to the Fuel Air Ratio under stoichiometric conditions, and is simply the reciprocal of AFRst.

Equivalence Ratio is the ratio of actual Fuel Air Ratio to Stoichiometric Fuel Air Ratio; it provides an intuitive way to express richer mixtures. Lambda is the ratio of actual Air Fuel Ratio to Stoichiometric Air Fuel Ratio; it provides an intuitive way to express leanness conditions (i.e., less fuel, less rich) mixtures of fuel and air.

As you can see from the table shown above this section, the ideal target AFRīs under boost for both gasoline and E85 are listed. For gasoline itīs 13.23-12.5, and for E85 itīs 8.47-6.975. However, with E85 you will not need to richen the mixture under WOT/boost as far as 6.975 or beyond. It does not need to be proportionally richer when compared to gasoline.

Why? Again, Because the fuel has a cooling effect on the intake charge and the space in which the combustion occurs. And at such a low AFR as 9.765 (lambda=1 on E85) or lower the fuel cools pretty good, donīt you think so?

Many people with some experience in mapping an ECU for use with E85 says that as high AFR as 8.5 or lambda=0.80-0.85 works well. No need to go to the extreme end of the useable scale to get safe power. It only uses a lot of fuel without giving any benefits.

E85 burns faster than gasoline at best mixtures so it is an inherently more effecient fuel. It also produces more exhaust gas for a give weight of fuel air mix giving higher average cylinder pressures inspite of lower EGT's. With streight E85 in a properly tuned car its good for about +5% power / torque increase. I suspect on a turbocharged car the benefit is larger.

Since you donīt have to richen the mixture as many percent (proportionally) as you have to on gasoline, you can make more power without having to use as much fuel.

How does ignition timing change on E85 ?
Timing on ethanol blends will not change very much. MBT timing for both gasoline and E85 are very nearly the same at light to moderate engine loads. At high engine load the E85 will want just slightly more advance. The big difference will be fuel/air mixture. The E85 will give improved torque with much richer mixtures than gasoline. Both gasoline and E85 will give best thermal effeciency at about 15% rich of stoich, so the equivalent of 12.78:1 on gasoline would be about 8.5:1 on E85, but E85 will continue to give better torque numbers up to about +40% rich of stoich or 7:1 mixtures, so on a utec you would want to richen up your WOT high load cells and add a tweak of timing to get the most out of E85 from what I've read. I run my car on 8.3:1 right now. I have tried much richer mixtures but i have not compared it on a dyno yet.

Quote:
Are you sure you don't mean that E85 will allow more advance?
Just passing on what I've found in the various sources. Logically you are correct, but one source says simply that MBT timing is the same for E85 and gasoline, and another report says at low loads the E85 and gasoline like the same MBT timing but at high loads MBT timing for the E85 is slightly more advance.

I suspect this is due to them not running ideal max power mixtures but cannot confirm it. Burn speed for E85 changes quite a bit with mixture, so if they were just a little bit lean or rich of ideal the burn rate would be lower.

Lots and lots of variables not well covered in some of the sources and in general they are focusing on emissions issues not max power torque so that would incline them to use less than best power timing advance. In a couple of the reports they also had limited control authority over timing and may not have explored the extremes very thoroughly.
I have also read that E85 burns much quicker than gas at rich mixtures soo if you have your timing advanced and go WOT you could get powerloss (And you micht not pick up any knocks) because of the burnspeed being to fast.


Economical gains:
So let me tell you guys about the fuel prices here in Sweden.
98 octane gasoline cost 12sek/L = $1.68/L = $6.36/gallon.
And 104 octane E85 cost 8sek/L = $1.12/L = $4.24/gallon.

Even that my car wants more fuel with E85 i still save money.

Runn

My experience with E85:
1. Better power (cooler intake charge, higher octane and the fact that it is cleaning the engine pretty good).

2. Smoother power and better stability at part-load.

3. After only 50 miles the tail-pipe began to get a lighter color. It was black inside before, now itīs brown and very transparent. My pipe is chromed and now you can see the chrome on the inside as well. When I have driven the car for a couple of 100 miles more I will tell you if it has got any cleaner inside.

4. The sound from the engine is different. It sounds more powerful.

5. The smell from the exhaust is much nicer. I cant describe the smell, When the car is hot i dont smell anything wierd. BTW i drive without cats.

6. The ethanol is cleaner and does not cause problems and if used in an E85 mix it will promote better lubrication of the parts in contact with the mixture and thus, will increase the engine useful life and ensure a significant increase in fuel economy.

Will my O2 sensor work with E85 and high ethanol blends?
The O2 sensor is not an issue, all it cares about is if your at stoich combustion at low throttle settings, it doesn't much care how you get there, so no need to change it. There is a thread about this on this forum somewhere where i explane this... (see if i can find i later)

What about oil contamination?
Modern lubricants, especially the synthetic oils are much much different than the oils used during those studies, and modern engines run at higher temperatures today which will quickly boil any traces of alcohol out of the oil.

How much will my miles per gallon of fuel drop with E85?
The only negative to E85 is that it gives a lower fuel milage on a gallon for gallon basis to gasoline. The actual difference in energy content between straight gasoline and E85 is about 27%.
The drop in milage is not as significant as you would think based on that difference due to the higher effeciency of the ethanol as a high performance fuel.
The lower milage is not really a big deal, ethanol has lower energy per gallon but your reduction in milage is not nearly as large as that difference would imply. Due to the higher torque,you use slightly smaller throttle openings to get the same level of preformance, and due to the greater quantity of combustion products (more moles of gas) per lb of fuel the engine effeciency actually goes up slightly.

Will a wide band O2 sensor accurately read fuel air mixtures with E85 blends ?
To get an accurate AFR reading you need to switch the meter to Lambda or equivalence ratio setting rather than AFR. Most O2 sensors assume you are running gasoline and will report a stoichimetric mixture as 14.7:1 which is the proper value for gasoline. E85 has a Stoichemetric mixture of between 9.7 - 10:1 and a max power mixture of about 6.98-8.5:1 or so, where with gasoline it is 12.5:1-to 13.1.

If you must use an O2 sensor that only reports gasoline AFR information simply divide the numbers it reports by 1.47 - 1.50.
The O2 sensors would still work. They don't understand AFR, they only understand rich/lean. If you are using regular or E10 the stoich AFR is ~14.7:1 (as you well know) and when the O2s are switching, this is the AFR it is indicating. When you are using E85 (AFR 9.765:1), the O2s will still work, switching between rich/lean. It's just that the point they are switching at is 9.765:1. You have to know what fuel you are burning to properly interpret the information the O2 sensors are providing.
Lambda 1 is always Lambda 1 no matter what you drive your car on, the o2 sensor doesnīt care if the AFR are 14,7 or 9.765... it measures the available o2 in the exhaust gases.

Is Ethanol less corrosive than Methanol?
Methanol is much more corrosive than ethanol. It attacks certain soft metals that are not much used in modern fuel systems. Years ago, the carburators were made of un-anodized aluminum and if methanol fuel was used, you had major problems with electrolytic corrosion between the aluminum and copper components used in the fuel system, since they were in continous contact.

That sort of corrosion only occurs when you have a current path between the dissimilar metals AND, a conductive path through the fluid in the system.

In Brazil where they have run high ethanol fuels since 1939, they found that to convert older cars designed for gasoline, long before ethanol blends were common, needed several changes to convert the cars over. This led to changes in valve materials, piston rings choices, nickle plating of the fuel tanks etc.

Modern cars in the U.S. are designed for use with ethanol up to 10% concentration in the fuel. That has led to several changes in component materials over the last 30 years that the U.S. has used ethanol enhanced fuels. All modern fuel lines and such are designed with the expectation that some ethanol will be in the fuel.

What about fuel system corrosion?
Corrosion does not appear to be an issue with modern OBDII cars. They are all certified by the manufactures to be safe to use on 10% ethanol fuel blends, and industry insiders say they are safe for much higher percentages. You don't install components that are "sorta safe" with a chemical, you put in a fuel hose etc. that is ethanol safe for concentrations well above what you expect to use. Not to mention that folks have been talking for years about raising the ethanol level to 20% or more.

Many years ago there were studies that indicated engines that ran on alcohol ALONE as a fuel, had issues with lubrication and valve seat wear. Keep in mind, those studies were done a long time ago, when engine oils were much less sophisticated than they are now, and some engine manufactures in the 1940's,1950' and 1960's made stupid engineering decisions and did not use hard valve seat inserts like stellite in the cylinder heads. This resulted in valve seat recession problems if you did not have lead additives in the fuel to protect the valve seats.


To sum it all up
Why is Ethanol a better fuel ?
1. It has a much higher evaporative cooling power than gasoline so the intake air charge in the cylinder is significantly cooler that it is with a comparable mixture of gasoline --- that means higher VE.

2. Its octane as blended in E85 is about 100, its blending octane when added to gasoline is rated at 118, so it is a very cost effective octane booster.

3. Ethanol burns faster than gasoline but has a slightly longer ignition delay during the slow burn phase of combustion so the engine does not do as much negative work fighting rising cylinder pressures due to large ignition advances. The total ignition advance for E85 is almost identical to the ideal advance for gasoline so it does not cause the PCM problems when you mix them.

4. At proper mixture you actually are releasing more energy in the cylinder due to the higher quantity of fuel you can burn. ( Ethanol can burn effeciently at much richer mixtures than gasoline can) That means about a 5% increase in energy release all by itself.

5. Peak combustion pressures are actually lower for ethanol than for gasoline but the cylinder pressures stay higher longer, so you have more (longer) crank angle that is usable by the engine. This lower peak cylinder pressure also helps with detonaton control.

6. Theorethically, the gain is 5% just by switching fuel. 350 hp X 5% = 15 hp, plus what can be gained from timing.

2000LS1TA

iTrader: (26)

nice write up, though I will still use 93

Runn

And what about the HowTo?

Actually there isnīt much you have to do..

1. Buy HPTuners.

2. Buy bigger injectors and istall them. Iīm using #42. Iīm going to upgrade to a better fuel pump in the future (at the same time that iīm installing new heads... AFR with high compression to take advantage of E85īs high octane)

3. Empty your fuel tank, just run the tank as empty as you can, Doesnīt really matter if there is some gas left, When you fill it up the next time youīl know you only have E85.

4. To save valueble "tuningtime" use HPTuners and change your Stoich AFR to 9.799 (look at picture). Or you can leave it alone but then you have to increase your VE-table alot more.

picture 1 http://www.putfile.com/pic.php?img=3918721

I found out that raising the Cranking fuel tables by 20% made the car easier to start and adding 15% to the OLFA makes the enging run smoother on warmup.

5. Iīve put my PE to look like this (and iīve also added a couple of degrees timing up top). Start with your standard timing and standard PE... We can talk timing and PE later on in this thread.
My stoich is put to 9.799 and my PE to 1.18 - 9.799/1.18=8.3 which if you look at the tables earlier in the post you would se that it a good value for lean power.

picture 2 coming later...

picture 3, itīs an old picture iv'e added more timing since... http://www.putfile.com/pic.php?img=3918723

6. Fill up your tank with E85 and put the new values in your PCM. Since the Stoich is changed the VE-table might not change so much it depends of how well your car was tuned before. But take it slow and tune in the low map at first. WB is recommended but you can tune in the lower part af the VE with stock O2. You should be able to feel the extra torque that E85 gives you
Of course you can mix it with gasoline if you want to and start with maybe 20% E85 and go from there and next time tune with 40% E85 and so on.

7. The E85 will clean the tank and fuel lines from old "crap" i recommend that you change your fuel filter when the fuel tank goes empty. Buy two because you really want to change it after a couple of tanks again. Better safe than sorry. E85 acts as an injector cleaner which is really nice, This means that your injectors are always in perfect "shape".

8. When you have your whole VE tuned in, Start experimenting with PE and timing (Be aware of the octane (104) of E85, you can use so mutch timing that you will loose power and possibly also damage your engine, This WITHOUT any knock) , A dyno will help alot here...

9. Post up your results. I am very interested at which timing you find most power at. Also if you have alot of dynotime experment with lean and fat WOT PE.

I canīt think about anything more right about now, But ask questions...

More info will come

8GTOKLR

iTrader: (6)

Great write up thats sticky worthy!!

Ashes

Awesome Runn... definitely worth a sticky.

BAD ASS TA WS6

iTrader: (5)

Very good info. Thanks for investing the time and writing it all down for those of us too lazy to search/experiment with this!

Rob

Magnet

iTrader: (36)

Ace$nyper

iTrader: (8)

Great read thanks

00pewterWS6TA

00pewterWS6TA

i put in E85 and my SES light cam on. didnt really notice a difference.

wannafbody

iTrader: (2)

can't you just mix E85 with gasoline?

BriancWS6

iTrader: (18)

Sweet writeup. I haven't seen any stations that sell E85 around here. Another thing is I haven't seen a comparison of pricing vs 93 to see how they match up, or how much less E85 would have to cost before it became cheaper to use over gasoline, with the fact that you have to flow at a higher rate of course. Interesting to see how this progresses as more time goes by....

Silver02TA

iTrader: (6)

did you follow his 3rd post or did you just put E85 in without doing a damn thing?

LS1LUNATIC

iTrader: (3)

Wicked write up. I havent seen any E85 stations here either but I would be really interested in switching if I could. Sounds like an ideal fuel, lets see some serious R&D from some sponsors!

Runn

Without any tuning the PCM cant give the engine the ~30% extra fuel that is needed. So the car will run lean and the SES-light comes on.

LS2Camaro

iTrader: (5)

Awesome write up, now we need to see some Forced Induction with E85 fuel setups, should be able to run more boost as the octane rating is higher which will mean less knock. Im sure that someone has or is working on a Turbo E85 F-body.

LS2Camaro

iTrader: (5)

Not that it will be different than a regular turbo setup (physically), but would like to see power Readings with Turbo E-85 F-body's.

promod1955

iTrader: (44)

If it takes X amount of fuel on gas to go x amount of miles, and it takes x amount of e85 plus another 30% to go the same miles, is the e85 going to cost more then gas to go the same distance?

its to early and i dont feel like doing the math.....

Runn

E85 is perfect for boost, I have many friends here in Sweden with forced induction that use E85... Thanks to the cooling effects and higher octane you can use alot more boost.
Just look at the Saab 9-5 Turbo with Biopower engine (big seller here in Sweden) that when it is fueled with E85 gives 20% more hp and 16% more torque compared with regular gas.