E-85 MEGA THREAD
12-10-2009, 08:48 PM
#152
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ok I'm on the verge of throwing together a 11:1 engine many seem to think this is ideal for E85 ...
i have stand alone and i will be able to switch maps without much trouble but around town there is one pump an hr away but there is lots of 98 and 100 pumps ...
how much would i have to compromise for 98 octane versus all mighty E85
i have stand alone and i will be able to switch maps without much trouble but around town there is one pump an hr away but there is lots of 98 and 100 pumps ...
how much would i have to compromise for 98 octane versus all mighty E85
12-10-2009, 10:49 PM
#153
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ok I'm on the verge of throwing together a 11:1 engine many seem to think this is ideal for E85 ...
i have stand alone and i will be able to switch maps without much trouble but around town there is one pump an hr away but there is lots of 98 and 100 pumps ...
how much would i have to compromise for 98 octane versus all mighty E85
i have stand alone and i will be able to switch maps without much trouble but around town there is one pump an hr away but there is lots of 98 and 100 pumps ...
how much would i have to compromise for 98 octane versus all mighty E85
Rod angle and bore has much to do with it all though.. Depends on your motor. For the 3.0. Piston size is a little larger, but the dwell time will be a little different (shorter) than the 2.5 also. All things to consider when adjusting timing. But in the end, Its just going to be.... add another degree... whats the egt's , power increase? Add another degree... whats the egt's, power increse? etc, etc, etc.
Last edited by 95ONE; 12-12-2009 at 12:39 PM.
12-10-2009, 11:17 PM
#154
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just seems like there has been little talk 100 octane tuning .its 92 or e85 US had 100 common on the pump for ever we were so jealous now seems its the other way round .
I will be instrumented up to the sunroof thermo couples and pressure transducers probably safeguard now.
and with all that stuff rigged up its probably a good time to start squirting propane and water in .
I will be instrumented up to the sunroof thermo couples and pressure transducers probably safeguard now.
and with all that stuff rigged up its probably a good time to start squirting propane and water in .
12-12-2009, 12:02 PM
#155
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I say this with all sincerity, I have literally had to stop and put pump in a few times over the years and it was as easy as lowering the FP or adjusting the AFC.
Again I just did this last weekend. It is really not that bad.
Obviously, having a separate tune is the way to go, but honestly..... Who's to say that it will be perfect for a mixture?? You will still have to tune slightly anyway depending on how much pump vs fuel is present.
Myself I have just found that running on E85 99% of the time works the best and just change the tune (via pressure or AFC) when I need to use pump gas. I have done this with stock injector size, 76# , and 96 # injectors. If the chip is mapped for the injector size the adjustment to get a good tune for E85 or pump is really minimal.
I am still unsure why everyone makes this out to be so difficult???
I may just have to stay away from this thread for awhile until more folks actually switch, and see how easy it is. There are a few ways to skin a cat regarding changing the fuel increase necessary. You don't have to have the latest and greatest software to do so.
Hell I ran around for well over a year on the stock injectors and only had to touch the FPR 4 times at most to compensate for the type of fuel.
Again I just did this last weekend. It is really not that bad.
Obviously, having a separate tune is the way to go, but honestly..... Who's to say that it will be perfect for a mixture?? You will still have to tune slightly anyway depending on how much pump vs fuel is present.
Myself I have just found that running on E85 99% of the time works the best and just change the tune (via pressure or AFC) when I need to use pump gas. I have done this with stock injector size, 76# , and 96 # injectors. If the chip is mapped for the injector size the adjustment to get a good tune for E85 or pump is really minimal.
I am still unsure why everyone makes this out to be so difficult???
I may just have to stay away from this thread for awhile until more folks actually switch, and see how easy it is. There are a few ways to skin a cat regarding changing the fuel increase necessary. You don't have to have the latest and greatest software to do so.
Hell I ran around for well over a year on the stock injectors and only had to touch the FPR 4 times at most to compensate for the type of fuel.
I guess I am asking if 3Bar is the magic pressure to stay at or is possible lower or higher FP been found more applicable.
01-25-2010, 02:49 PM
#156
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Once again.. mixtures are different at different types of the year on PURPOSE! Colder temps = slightly harder start for e-85. So the winter mixtures are PURPOSELY less E-85 with more fuel..
It also depends on where you are geographically. Here in Houston, colder temps aren't a problem.. Ever. So it's almost always an 85% mix.
It also depends on where you are geographically. Here in Houston, colder temps aren't a problem.. Ever. So it's almost always an 85% mix.
is the reason e85 is harder to start on cold days because it doesnt burn like gas does? if so, could some of the hard start issue be resolved by running more timing on idle? or would that only come into play once the engine is running already?
and regarding AFRs (assuming the gasoline scale for ease of thinking), for low-load tuning (say, below 30% throttle), would i be able to get away with, say, 14:1 for economy? and then with higher than 30% maybe drop to 13-12.5:1, and then at WOT down to like 11:1? or how would/do you guys set your fuel?
01-25-2010, 06:58 PM
#157
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E85 does not atomize as easily when cold. That is the major contributor to hard-starting. It is also a little bit slower to warm-up. But really not that big of an issue. I've not had any issue starting mine here in CO...
You tune E85 very similar to gasoline.
Low-load : shoot for mid/high 14's
mid-load should be low-13s
boost > 5psi, start sloping down to mid 11s by your set boost.
-Rogue
You tune E85 very similar to gasoline.
Low-load : shoot for mid/high 14's
mid-load should be low-13s
boost > 5psi, start sloping down to mid 11s by your set boost.
-Rogue
01-26-2010, 01:35 AM
#158
Rainman
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how does the dme understand having larger injectors than stock? i know you plug the numbers into the fqs but like how does it compensate for that when trying to reach, say a 12:1 afr?
01-26-2010, 01:39 AM
#159
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The DME simply lowers the IDC by a certain percent (whatever you set the FQS to be).
Fuel quantity necessary for stoich is first calculated, then the different map/table values get applied. Pretty simple
Fuel quantity necessary for stoich is first calculated, then the different map/table values get applied. Pretty simple
01-26-2010, 01:50 AM
#160
Rainman
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so if i set it to say 55lb injectors for stock position on e85, it will run the injectors at whatever duty cycle to match the incoming airflow, and if i were to switch back to gas id just tell it that fqs position 2 is say 38lb (~30% less) and it will fuel accordingly, even with the same amount of airflow?
or would i tell it on the fqs position for e85 that its at 38lbs even though its really 55lbs so that it runs rich permanently
or would i tell it on the fqs position for e85 that its at 38lbs even though its really 55lbs so that it runs rich permanently
01-26-2010, 02:16 AM
#161
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For E85 you have to account for the ~25% more fuel necessary...
So for your E85 setting, I would try ~42 for the FQS setting.
For Gas, use the normal 55lb setting
So for your E85 setting, I would try ~42 for the FQS setting.
For Gas, use the normal 55lb setting
01-26-2010, 05:00 AM
#163
Rainman
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since i wont be using anywhere near 55lbs/hr of gasoline will those injectors kill my mileage or will the dme be able to compensate with just really low idc?
01-27-2010, 01:35 AM
#165
Rainman
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god, computers are great.
if e85 gets tuned to similar afrs to gas, then i shouldnt even need to change my fuel maps when switching fuels, just the injector size selection, huh?
if e85 gets tuned to similar afrs to gas, then i shouldnt even need to change my fuel maps when switching fuels, just the injector size selection, huh?