trying out e85

[johnmarines]

I just decided to switch over to e85 and see what happens. I filled up with 10 gallons (I was at 1/8 of a tank)... changed my global to -30.9 and deadtime to 330. It does seem alittle more peppy but when I gave it a little more throttle it started bucking about 3000rpm's... any insight on what I need to change?

 

[matthewdesigns]

Well, some related things come to mind. You need to add about 30% more fuel when switching to e85, not pull it out. This would explain your scary-lean condition (18+:1 afrs), resulting in 1.4* of knock, and timing being pulled down to 5*, resulting in the crappy driving.

Try adding the fuel, not subtracting it, and have another go at a partial-throttle log like this. And keep an eye on your wbo2 gauge while you are doing it. You should see afr's at/around stoich if everything is good, just like on pump gas.

 

[jeffo]

Are you sure that your station is actually pumping E85 this time of year? I'll bet its actually E70, which would make you run very rich, causing "sputtering" under boost.
Also, PTE lies about their injector size. Figure ~935cc instead of 1000cc in your Global Fuel calculations.

 

[johnmarines]

I'll give it a try... also I just found out that I need a buffer on my wideband for it to read correctly... I just ordered it.... thanks guys...

 

[JayRolla]

E85/E70 is not much different. I cant even tell when they switch it because the ecu takes care of it. WOT will barely lean out but thats what is great about e85. You can run rich around 10.9-11.5 and make as much power as 11.5-12.5. Makes good power at any AFR unlike gas.

Just read your WBO2 off the gauge. Dsmlink does not log AEM wbo2 correctly even with the buffer and its a PITA. Im going to swich my AEM out soon because of the issue. I use the linear wbo2 feature but its impossible to get perfect.

 

[jeffo]

How does your ECU "take care" of a 15% reduction in ethanol?

 

[johnmarines]

I just changed my global to -42 and it accelarates alittle better but I am still sputtering... am I going in the right direction? My w/b is sitng around low 13 to mid 14....

 

[the_mork]

13 to mid 14....

At idle or WOT? Idle will take care of itself to the point where you can't tune for an idle AFR directly. What you need to watch are your fuel trims and you need to get them as close to 0 as possible. WOT you can tune directly and if you are at 13-14 then you are doing something that is very scary. Try to richen that up significantly with your global fueling until you are seeing 10.x:1 and then start fine tuning areas until you get your car to consistently give you something like 11.1:1. I actually am not sure what an ideal ratio is for e85 but that is what I would conservatively tune for on gas so it should be fairly safe. Of course that isn't the real AFR with e85 but because your wideband calculated AFR off of lambda it means the same things.

 

[SlowSpyder]

Stoich for e85 is around 9.7-9.8 . You need more fuel.

 

[jeffo]

What is your LTFT doing? The MID LTFT is a good indicator on whether the ECU is trying to add or remove fuel while cruising in closedloop. Tune the Global Fuel to keep the LTFT at 0.

 

[mikelv]

Stoich for e85 is around 9.7-9.8 . You need more fuel.

Where do you come by this information? I would like to know your source.

I just changed my global to -42 and it accelarates alittle better but I am still sputtering... am I going in the right direction? My w/b is sitng around low 13 to mid 14....

I have used E85 seldom, because 110 here in SC is very easy to come by. I don't mind paying a few bucks more for it. (4.30/gal)
My personal experience, I had to add a significant amount of fuel in order to maintain the same A/F ratios as I did with leaded or unleaded gas. Since you have, a wideband here is probably the best way to get the settings that you need. In open loop, the car should take care of itself. I would say there would be minor adjustments if any when the car is riding.
When you go wide open, you need NOT worry about global adjustments. Instead, you need to adjust your fuel sliders (tables) as these settings are only be applied at WOT, or certain closed conditions.
When you start to tune, I would use my baseline settings, but with E85, you need to INCREASE the amount of fuel needed significantly to achieve the same A/F ratios as with regular leaded/unleaded fuel. Now I’m not a chemist or anything, but I do know this is true; I had to add about 25% more fuel on my tables in order to get the car in the 11.5/1 range. So if you’re boosting and taking fuel out, that’s why you’re sputtering. Don’t do it anymore, you’re going to break shit.
The biggest issue you’ll have with E85 is running out of pump, (fuel pump) or injector, so the best thing to do is keep an eye on your injector duty cycle (IDC). If your pushing 80% or more than you’re probably going to need more to get the job done.
Quick look at your setup, if you have 1000’s and a 255lph, you should have plenty to get it done, my guess is that your IDC’s would be 75% or so depending on how much boost you run. Just FYI, I ran 27 pounds on E85 with 1050’s and a Supra Pump….my IDC’s were 85% and I still made 550-horse. But that was pushing it to the limit, and I surprised a lot of people. Bottom line, don’t run out of pump.
16g with internals, you should have no problem running that bi*** to the max. I would look at a bigger turbo next, you can out boost your setup easily with E85 or race gas.

At idle or WOT? Idle will take care of itself to the point where you can't tune for an idle AFR directly. What you need to watch are your fuel trims and you need to get them as close to 0 as possible. WOT you can tune directly and if you are at 13-14 then you are doing something that is very scary. Try to richen that up significantly with your global fueling until you are seeing 10.x:1 and then start fine tuning areas until you get your car to consistently give you something like 11.1:1. I actually am not sure what an ideal ratio is for e85 but that is what I would conservatively tune for on gas so it should be fairly safe. Of course that isn't the real AFR with e85 but because your wideband calculated AFR off of lambda it means the same things.

I agree, just don't worry about messing with global adjustments once you've dialed in cruise. It'll only mess things up when tuning WOT.

 

[My1GLaser]

I am on my work PC which doesn't have V3 installed so I can't view the log. I calculate -30.6 for global on 100% E-85 so you must have used the correct equation. (Using 940cc from the DSMLink Wiki.) But you only have 12 gal total & 2 gal is pump, so redoing the equation I come up with -44 global so your second adjustment is close and that is why it is running better. (83.3% E-85 & 16.7% pump)

The only way to do it correctly IMO is to tune your fuel trims again when you switch to E-85. This way you will see how accurate your global is for that particular blend of E-85 & pump by watching fuel trims. I stick with a 50/50 mixture to keep it simple.

I had to use my fuel sliders to get my AFR where I wanted it for WOT which is about 12.5:1. I don't remember how many % I pulled from my old pump gas tune but I want to say at least 5% maybe...

What is your spark plug gap?
Do you have an exhaust leak before your WB? How old is the sensor? Run much race gas lately?

 

[92DSMErdrick]

Where do you come by this information? I would like to know your source.

e85fuel [ECMTuning - wiki]

 

[johnmarines]

I had to use my fuel sliders to get my AFR where I wanted it for WOT which is about 12.5:1. I don't remember how many % I pulled from my old pump gas tune but I want to say at least 5% maybe...

What is your spark plug gap?
Do you have an exhaust leak before your WB? How old is the sensor? Run much race gas lately?

My spark plug gap is stock(can't remember off hand) and as far as a exhaust leak before my w/b... no... and the sensor is about 1 1/2 yrs old.... about 8000 miles. The car has not been tuned since the new motor install. The shop that was going to tune it for me is on back log for 3 weeks , so I would have to wait. I am just trying to get a good base tune so I can drive it untill it gets tuned. Let me see if I understand this correctly. .. I zeroed out my fuel and timing so I need to add fuel to my sliders for WOT? what increments should I start with?
As of right now I am seeing 14.7 at WOT on the w/b

 

[mikelv]

e85fuel [ECMTuning - wiki]

Good page, been outta touch for a while with E85.
I wasn't trying to sound smart, just wondering. Thanks.

As of right now I am seeing 14.7 at WOT on the w/b

This is extremely lean, as stated, you need to add a significant amount of fuel in order to obtain similar A/F Ratios seen with different mixtures, like normal pump gas. Fuel sliders are values only applied WOT, global will affect the entire tune, WOT and part throttle.

Again, I'm not an E85 expert, just trying to talk from experience, but getting 25 lbs of boost out of E85 on a 255lph and 1000's should be just fine. IDC's shouldnt peak above 75%, if you do then you have a problem with the pump, or AFPR isn't properly set or something to that nature. Bottom line your car is running out of fuel, not a good thing.


Also, you can gap .025 to .028 without any problems. For boost pressures 15-20 pounds, you can run NGK BPR6ES's with a normal gap of .028 and not worry about blowing out spark at all. Above 20 pounds, say 20-25 I would go up to 7ES's and you would be safe to drop the gap to .025 or 26....should make much of a difference of keeping things the way you are, depending on your goals, ect....

I run 9ES's @ 36 pounds with a gap of .022 with no problem...

Also, if you zeroed out your fuel table, you'd be super rich.....keep the global set based on your injector size and make minor corrections to the sliders to find the proper A/F ratio for the mixture of gas you have in the tank.

Just my opinion, but if you're waiting for someone to tune your car, just wait....it's not worth it. If you don't have a lot of experience with this you can really mess things up bad, trust me I've learned the hard way too many times....




EDIT-----


Hey John,

I dug into this E85 deal a little bit and I hope I can give you some better insight as to what is actually going on, benefits, pros/cons, to running the corn fuel.

The Wiki page is a good reference to give you some insight as to what E85 is all about and what to expect when running this type of fuel in your turbocharged engine:

Here a a few subjects quoted from the wiki page. I bolded a few key points:



Turbocharged engines


E85 gives particularly good results in turbocharged cars due to its high octane. It allows the ECU to run more favorable ignition timing and leaner fuel mixtures than are possible on normal premium gasoline......... Fuel system compatibility issues have not been reported for any OBDII cars or light trucks running on high ethanol mixes of E85 and gasoline for periods of time exceeding two years...............



Corrosion


E85 can cause damage, since prolonged exposure to high concentrations of ethanol may corrode metal and rubber parts in older engines (pre-1985) designed primarily for gasoline. The hydroxyl group on the ethanol molecule is an extremely weak acid, but it can enhance corrosion for some natural materials. For post-1985 fuel-injected engines, all the components are already designed to accommodate E10 (10% ethanol) blends through the elimination of exposed magnesium and aluminum metals and natural rubber and cork gasketed parts...... Nonetheless, operation with more than 10% ethanol has never been recommended by car manufacturers in non-FFVs. Operation on up to 20% ethanol is generally considered safe for all post-1988 cars and trucks.



Air/Fuel mixture problems


Running a non-FFV with a high percentage of ethanol will cause the air fuel mixture to be leaner than normal in carbureted or open loop fuel injection engines, and cause closed loop fuel injection systems to adjust for the increase in oxygen content of the fuel mixture. A lean mixture, when leaner than stoichiometric, could cause heat related engine damage because combustion chamber temperatures can increase with a surplus of air during the combustion event. Some aftermarket E85 conversion kits for modern fuel injected vehicles operate by altering the duty cycles of electronic injectors to help offset air/fuel mixture issues. The effects of surplus oxygen on the catalytic converter may be undesirable, and if too lean the engine will display roughness in operation. If the percentage of ethanol used results in sustained operation in the range between stoichiometric and best power mixture, problems may develop. In this range, between peak exhaust gas temperature and approximately 50 degrees rich of peak, combustion temperatures are at the highest possible, and may exceed the design temperatures for the engine. Detonation margins are reduced, and if operation at elevated temperatures is allowed to persist over considerable periods of time, heat related damage to valves and pistons can occur.

Without in-depth knowledge of the engine's mixture control system and instrumentation to monitor exhaust gas temperature, cylinder head temperature, cylinder pressure, and/or exhaust oxygen content, it is difficult to know whether the engine is operating in the "red" zone, or an acceptable mixture zone. Closed loop fuel injection systems eliminate much of the risk. This is also why the check engine light will illuminate if you mix more than around 50% to 60% E85 by volume with your gasoline in a non-FFV. If this happens, just add more gasoline as soon as possible to correct the problem. (Keep in mind that retail stations dispensing E85 are likley dispening gasoline with 10% ethanol.) These fuel/air mixture related problems will not happen in a properly-converted vehicle.





When we talk about A/F ratio mixtures with an ethanol mixture, we talk about higher oxygen content for the same amount of volume as regular gasoline. For example, 1 gallon of pure pump gas contains a less oxygen than 1 gallon of pure E85. So if you ran E85 as a pure mixture, you would have to compensate for this increased amount of oxygen. Hence, the large increase on your fuel sliders in order to make the mixture rich enough (cool enough) to not melt engine parts.

To make it as basic as possible, I would say that the same tune you run with pump gas has to be increased a certain percentage in order for you to obtain the same safe combustible mixture with straight E85.

Now to reduce the amount of oxygen in the mixture and make it safer to run, guys will add pump gas to the mixture so you're not running pure E85 blend in the tank. For us, it defeats the purpose because the whole point is to make more power. Now in order for us to make more power and not make the highly oxygenated mixture too lean for the engine (keeping the E85 mixture as close to pure as possible), we need to dump an ass load of fuel. We do this by having the correct components (larger fuel injectors, fuel pump(s), and APFR) and engine management, (DSMLink, AEM, ect...). So in the case such as yourself or others, you have DSMLink, big injectors, a pump, APFR, you can make more power with E85. Just ensure you monitor your IDC' (Injector Duty Cycle) because the major concern you will have (or others tuning E85 with the proper components) is literally not being able to pump enough fuel in the engine to keep the high oxygen-rich mixture cool.

That's how I see it, but I would appreciate some input from others, I kind of just whipped this up off the top of my head. Haven't posted in a while, so thanks to all who have more experience with E85 that can help clarify.

 

[JayRolla]

Your info is pretty dead on. But he should take 30% off his injectors and set up the global for that. So start at 700cc injectors and this should be pretty close to stoich for e85.

 

[MIdsm]

Just a dumb question. Did the OP measure the lambda and then multiply by above quoted 9.7 stoich for e85 to get his AFR or is he going off the gauge that's calibrated for gasoline? Lambda is what's important. As long as lambda is near one the mixture is stoichiometric. A gauge that's set for gasoline ought to show 14.7 when lambda is 1.0 no matter what the fuel is. The gauge just multiplies the lambda by an arbitrary number (14.7 for gasoline).

 

[mikelv]

Just a dumb question. Did the OP measure the lambda and then multiply by above quoted 9.7 stoich for e85 to get his AFR or is he going off the gauge that's calibrated for gasoline? Lambda is what's important. As long as lambda is near one the mixture is stoichiometric. A gauge that's set for gasoline ought to show 14.7 when lambda is 1.0 no matter what the fuel is. The gauge just multiplies the lambda by an arbitrary number (14.7 for gasoline).

Not a dumb question, this is actually a very good post.