SpinMonster

This is NOT ABOUT RUNNING E85 in your car.

Its about running 10% more ethanol than you do now. Almost all of your cars are now running E10 and your tune is now wrong. You can add just one gallon to 5 gallons of gas and pick up 30rwhp on a full tune (a tune gains 12-15rw on a stock car, this is another 15) and you dont need bigger injectors. THIS MOD IS FREE!!!

Running E85 in your car need not be done with 100% of the fuel being E85. In fact most places in the US actually run E10 as gasoline. When you're at the pump it has a sticker on the front to say its 10% ethanol. If thats the case, your tune is already incorrect for the stoic value it uses for this fuel. E10 or 10% ethanol actaully has a richer stoic. Cars running E10 will run higher LTFT's and apprear to be leaner and this is why they run so rich at WOT. PE uses the closed loop LTFT's to meter how much fuel to dump at WOT.

The biggest issues surrounding the use of E85 is the fear that is bad for the fuel system, reduced range on a tank of gas, and reduced fuel system (hp) capacity of a given system. Since ethanol is in your fuel by 10% in most places, you can run E20 and get a 2 point jump in octane or E30 and get 3.5+. This then gets you some added octane without expensive octane boosters, or fears of 85% ethanol content. Your fuel system capacity wont suffer nearly as much and you will also not need bigger injectors unless you were over 85% duty cycle. Those worried about varying ethanol content such as E85 actually being E70 in the winter can use the link below to get the dates of the switch. If you tune for the higher ethanol content and you get less ethanol, the car runs richer to compensate and since you werent using that much, the difference isnt big anyway. Cold starts also wont be an issue because the ethanol content is so small.

Here is a chart for stoic values for the varying amounts of ethanol. This chart assumes the equivalent of 13:1 for PE in n/a applications and assumes a 11.25 for boosted applications. Please note that for a given car, the ethanol likes to be richer for PE than its gas tune equivalent so shoot for a bit richer using these values as the leanest you should be. It is likely that max power will be with a richer mix. It also assumes your area is running E70 now because its winter (helps with cold starts).My car is running E20 and it works awesome. I added some low end timing and its sick how much TQ it picked up. I am running 10 degrees less timing than I can run. I have it super safe and pulled the power back to have the Mickey Thompsons stick somewhat.


Once you determine the mix of gas you want you can then add E85 to the mix and determine the ethanol content you need for your approximate octane desire. You would then have essentially E20. If you need 98 or 99 octane, run 1/2 a tank of E85 and use the E40 line. Go to the above chart and look at your required stoic and input that as your value in HPtuners like this:



You would then be pretty close for an N/A tune because the PE table adds fuel to the stoic as the base. Looking at the above chart the PE a/f ratio for this stoic is about 12:1 for N/A cars using 20% ethanol. The PE calculation is then 13.6/12=1.133. A bone stock tune in the 2007 SS for example has 1.14 to 1.2 in most PE cells and leaning these out restores some of the lost MPG. Now for you guys now running E10...you car is tuned for 100% gasoline and the tune is off by the same amount as if you tune for E10 and run E20. You may want to think about that before dismissing this mod. Go back and read it again. If not, you're missing a really BIG point.

In summary, you dont need to use 100% of a tank of E85 to get awesome benefits of this cheap race gas. If you use your car for a road trip and cant find E85, this tune isnt as far off as a dedicated E85 tune and wont run any where near as rich. Adding 2 full points in (edit: octane) will allow a tune with about 3-4 degrees more timing and thus a tune instead of seeing 16-20HP will see about 33-35HP with mods.

Last up is that the E85 blend varies by location and season so here is a chart for what blend is sold at these times and locations. This lets you know if its E70 to E85 at a given time and place.
http://www.e85mustangs.com/regions123.html

Hope this helps guys that wont run E85 due to some downsides.

In comparison to meth injection: There cant be a pump failing (not that this is much of a concern anyway), the ethanol only jumps 10%, it works low in RPM where meth wont be firing, and best of all, its free to do this change if you have HPtuners!!!

FREE.99

Meth still adds to the power by lowering IATs with the spraying by about 30 degrees. Ethanol is reduced in this application but it lowers combustion chamber temps.

WIDEBAND CONSIDERATIONS

All widebands are actually lambda meters and 14.7 is stoic. When you use the mix as stated above, you dont change how you read the wideband. PE is that percentage richer than the stoic value you input. So if youre at 13.6 for E20 stoic, your wideband reads 14.7 for stoic as usual. Your PE reading is going to be pretty close to the 12:1 with 20% ethanol when it reads 13:1 n/a or 10.34 when it reads 11.25:1 for 650rwhp.

Feel free to add comments or even bash as long as you do it with love. My chart above is extrapolated and as usual it was done over night last night and can have errors. I thought E10 was 14.4 stoic but my math says different. Input is appreciated.Please keep in mind that errors of less than 1/3 a point are still not as far off as running a 100% gasoline tune on E10 at the pumps.

a bientot au revoir.

filmjay

Thank you sir.

E85 isn't widely available around my neck of the woods. Everybody has E10 though. Funny, since owning the Vette, I've always tried to avoid the ethanol mixes as we still have a few places still selling the straight 93 gas.
Before taking my car in for a SC install last week, the only gas available off the I-state was E10, so I filled up with that.

So it's pretty safe to assume the car will be tuned with E10.

As a counterpoint, How would running straight 93 affect an E10 tune? Should I now avoid the straight 93?

You've already sold me on meth. Thanks again for your efforts and being so forthcoming with your findings.

SpinMonster

Having tuned (more to the point, retuned) cars that have lots of mods, I have yet to see one tune that had the stoic value changed so I seriously doubt your car will get this change unless you ask for it. Since its safe to say that 70% of all corvettes out there run 10% ethanol without knowing it, it stands to reason that being off by 1/3 to 2/3 of a point on the stoic value will not hurt your car. So running a car with a stoic of 14.1 with 93 octane is no better or worse as long as the WOT tune reflecs the proper a/f ratio which a stock car doesnt. The tune is by lambda reading and will be dead on at WOT but closed loop will run lean on E10 but the car compensates in a -14/+24% range so it isnt actually running lean. The funny thing is that our PCM only compensates in the safe direction. Cars running E10 run lean LTFTs at cruise and thus run richer WOT because positive LTFTs cause more fuel to be dumped. In the case of running gas on an E10 tune, the car runs richer at cruise and only runs the commanded PE fuel amount to protect from going lean. Kewl deal.

Contrary to your wanting 93 over E10 I would take the E10 over 93. It burns cleaner and there's nothing wrong with going green especially when its also clean inside your engine. Ethanol as a fuel is superior to straight gas. If it didnt eat up my fuel system's capacity requiring more fuel pump to support my HP level, it would be the only thing in my corvette.

E10 is not bad in any way to anything in your car nor would the E20 or E30 mixes proposed here. Methanol is far more corrosive than ethanol and no one is complaining about meth systems hurting their car. E85 tear downs after 110k miles revealed a very clean and healthy GM engine that showed much less wear than a gasoline run engine.

All of these options are using diluted versions of these fuels.

SpinMonster

This is NOT ABOUT RUNNING E85 in your car.

You now run E10 in your car.

This thread is about running 10% more ethanol than you do now. Almost all of your cars are now running E10 and your tune is now wrong. You can add just one gallon to 5 gallons of gas and pick up 30rwhp on a full tune if you're bone stock, and you dont need bigger injectors.

THIS MOD IS FREE!!!

When you get your car tuned, tune it for E20.

c6 batmobile

Ok lemme see if I understand this correctly. Currently I run about 10% ethanol in my gas because that is what is available. So If I add another gallon of ethanol I adjust my stoic air up 10% from what it is now and it will add hp?

I dont really understand what youre saying unless you make it super simple so Im trying to break it down for myself and others that may be slow like me.

RLSebring

Spin, I know of several people that will find this write up interesting.

I don't know if you have ever read any of my threads concerning the idle quality of my car. I had went with the 480hp Hot Cam crate motor for my 08 A6 Vert.

I, and several other "Tuners" have had fits trying to get this motor to idle. It runs pretty good in all other aspects. It's taken close to a year to get it to where it's at now and it's probably 97%.

With the help of Motorhead47, we adjusted the Stoich value recently from the stock 14.6 something to 14.2 taking in consideration of the E10 in our area.

That adjustment made the single most improvement to my car running somewhat smooth. Just that alone got rid of 90% of the surging bucking etc...

In looking at the above Stoich value you have the 13 something in all % cells. We changed just the 0% value. Do I need to have all cells the same or is yours set up differently for mods? Mine is basically stock except for the hot cam part.

I was telling Motorhead47 that the fueling adjustments are constantly improving the running of the engine. This may still be an area to deal with.

As far as timing at least in the idle range I am at 19 degrees then jumps pretty much to the stock table once the car is rolling. Anything above 19 degrees seems to degrade the idle. Do you think the Stoich values in all ranges may improve this?

I appreciate the help and surely appreciate this latest writeup.

PowerLabs

Great post Spin... I know a lot of people would love to be running more Ethanol in their fuel because it is essentially race fuel (Octane rating = 113) but with much better charge cooling on vaporization. Sadly for us folks here in the East Coast it is just non existent... Your trick of only adding *some* Ethanol to the tank instead of filling it up also circumvents most of the drawbacks of running E85: Lower fuel economy, difficulties cold starting, and running out of fuel capacity up top for high HP cars... Great mod! Let me know if you still want me to post that Excel file

SpinMonster

You're closer than you think. Currently you run 10% thus should be about 14.1 to 14.2 on your stoic. If you add 1 gallon of E85 to every 5 gallons of gas (that has 10% ethanol) you will have 95 octane instead of 93 and you tune for E20 on the chart or 13.6. This allows for a better tune. If you drive to places you cant bank on getting E85 for the mix, dont add timing it cant run on E10.

SpinMonster

Your car doesnt have a flex fuel composition sensor so it doesnt read any value other than the 0% cell. I adjusted all cells this way to make sure there arent other reasons it may jump cells. The tune reflecs possible future shifts to flexfuel and hence they include the composition stoic values for various levels of ethanol. Had the sensor been present, our cars would read 14.1 when using E10 but it doesnt hence the table is useless without the sensor. I have a wideband mounted permanantly on the pillar and I can tell you it didnt richen up when I added more ethanol.

I think 2005's have the same value in all cells from the factory as per several tunes I looked in. The above tuning screen shot is from a 2007 trailblazer SS that I did this to. The tune was day and night. It took 4 degrees past what our 91 octane allows and is now at 93.5 at this altitude or what would be about 96 at sea level. I know 30rwtq when I feel it from experience. If you can run the E20 tune with 22 degrees, you will gain 15HP over the best 93 octane tune you can run and there will still be headroom for hot days. It also burns cleaner and being that it hardly taxes the fuel system, the stock injectors and fuel pump are fine for H/C cars up to 97 octane with 2 gallons of E85 per 5 gallons gas. This is a dream come true for Cali cars stuck with 91 at sea level.

Colorado's cylinder pressures are 25+% lower so 91 is fine here with meth. I like both options. Ethanol just burns better than gasoline.

Motorhead47 has demonstrated some really good understanding of the platform. It appears you're in good hands.

PRE-Z06

Good info, thanks for taking the time to post it!

c6 batmobile

So Im not as retarded as I feel when I read your post. I kinda understand what you are saying. Im gonna look at that value and see about aquiring some ethanol to play around with this. Its worth some extra hp at the track Im in.

shizon'00

Hey spin,

As you know, I'm a big ethanol supporter so not trying to start a fire here, but it just doesn't add up and I need more info on what you're claiming. The biggest reason is blended octane does not equal octane as most of us know it at the pump. Are you saying you think you can get the same results as an E85 or E100 car with an E20 car? I'm a bit confused.

If you have them, post dyno results. This one is a little hard to believe and the explanation doesn't add up to me. Otherwise, I need to better understand the claim of the numbers if you haven't seen it, only felt it.

Hope this post doesn't come across the wrong way. Just wanna share data.

Also, you mention adding 2 full points in compression. I assume you mean adding 2 full points of octane. Just wanted to clear that up.

Mez

Good info. I recently started adjusting stoch because of the E10 fuel.

I had tuned my car so all the LTFT% were between -3 and 0 per the Greg Banish book. Then I got a tank of E10 and my LTFT% went up by 5. So I changed stoch to 14.2 and saw the LTFT% back to where they were. This was fine for a couple of tanks, then I filled up at a Shell which had the E10 sticker but immediately my LTFT% went to -8 to -10. Must be 100% gas I thought, so I changed stoch back to 14.7 and all was well again.

I would like to state how the PE table works in my mind.

The PE table is a multiplier on Stoch to command a desired A/F ratio. So if your fuel is 100% gasoline, stoch is 14.7. Then if you want to command a 13.0 A/F ratio when in PE mode, you set the PE to 1.13 (the math is 14.7 / 1.13 = 13.0).

So if you are running E10, you set the stoch to 14.1 so when you go into PE mode, the commanded A/F ratio will be 12.5 (the math is 14.1 /1.13 = 12.5) which where you want to be.

Is this correct?

Another thing that is confusing me is comments about the LTFT%. As I understand, LTFT% stored value based on 10 counts from the STFT% error which is calculated on the amount of 02 measured by the Narrow Band O2 sensor.

Correct me if this is wrong, but if your LTFT% is +5% in a particular cruise cell, and STFT% is 0%, the actual A/F ratio is whatever stoch is set to thus its not rich or lean. I understood the LTFT % error is set in a certain cell based on a number of STFT % errors. So the engine is not running rich or lean in that cell.

Thanks and will monitor other comments.

AndrewZPSU

I ran both a mix on my car and full E85. The mix by far was awesome for the track.... but it was a little higher mix. I called it E63 I believe. That was on the stock everything.

In the heat I was running the same times and MPH as a full bolt on and cammed LS3 Vette.

SpinMonster

Sharing requires you supply some info too, not just critique mine....anyway, yes, I meant 2 points of octane.

No where above did I say that E20 equals E85 in octane. Please quote what you think says that as I dont think you read it fully.E85 is 105 octane. E10 is what you get at the pumps and adding 1 gallon of E85 to five gallons of 93 does indeed get you 95 octane. No, it isnt getting you 105 octane running 1:5 of E85 to 93 nor did I imply that.

As far as dyno data no I dont have it as most people going this route arent going to foot the bill for dyno time for others to benefit. I will eventually have plenty dyno results. When a car that cant run 19 degrees peak timing is able to run 23 degrees with no knock retard, it gained power. The GTO I did this to couldnt break first gear loose is now doing that on a throttle roll in for 2nd gear. I tuned 4 cars this way including mine.

If you're arguing that octane doesnt go up when 16.6% of whats in your tank is 105 octane, I think you're on your own. If you would like to donate the time to calculate the resulting octane of adding 1 gallon of 105 E85 to 5 gallons of E10 at 93 please do.

Please share data.

SpinMonster

Yes you have the first part correct.

The LTFTs between -14 and +24 are held at stoic by the PCM. However, when you are positive, the PCM adds fuel to the commanded PE. If you are +5 and you commanded 12.5, it will be 5% richer than that. When LTFTs are non-positive (zero or a neg value), the PCM doesnt change the commanded PE. This is why Greg said to tune for non-positive values. This is done to keep a lean mixture from being lean at WOT under load.

This all requires a car to be tuned for E10 with the correct stoic. Many cars running around make their best power under 13:1 because they are most of the time running a mix of ethanol and want to be richer at 12.5 or so. Now we see one reason why. Please understand that ethanol likes being richer than gas for max power, so gas liking 13:1 or 13% richer isnt optimum on E85. It actually likes richer lambda values for what would be closer to a PE of 1.22. E20 will make its best power between 1.15 and 1.18 in PE. Use the 12.5 on your wideband (set for 14.7 stoic) at about 12.4 with 12.5 being the leanest. If your wideband is reading 9.765 for stoic = 1 (lambda) on E85, you will see 8.1 or so at max power with a leanest value at 8.6. Boosted cars go richer of course.

SpinMonster

Do you have any of the tuning data?

Can you e-mail me the tune you used?

SpinMonster

If people take nothing else away from this thread, they should tune for E10. If they get E10, fine. If they get 100% gas, they are no worse off then they are now. If they use E20 with a E10 tune, again, the tune is no worse than they are now with E10 running a gasoline tune. The octane improvement is there with 16.6% of the tank filled with E85, E74, or E70 whichever is present at the time they fill up.

StoplightWarrior

Interesting...

but I can't simply start adding 1 gal of ethanol with every 5 of 91 and expect to feel more power, w/o tuning for this addition, right?

shizon'00

Nevermind...it's not worth my time. I'm sure someone else will do the research. I've shared plenty with you already Jay even though there was no acknowledgement and I'm happy to with anyone else that PM's me like you did last year. These E85 threads always turn into a mess (both ways) because no one can actually show any real data.