Going lean on wot on e-85
The lower temperature in the evening, compared to the 105 deg F you set your tune at, means that the air is denser and so your engine is actually getting more air. Unless you increase the fueling to match, this will make your AFR higher, i.e. leaner. E85 fueling is more sensitive to temperature changes than gas probably because of it's higher flash point and greater latent heat of vaporization.
Are you logging your runs? Mind posting a day and night run?
I am still working on understanding SD with 93, I have yet to start messing with it on E85 as temperature seems to affect it.
With out seeing a log atm you may just want to put a little more fuel back in it where it goes lean in the cooler air.
I am still working on understanding SD with 93, I have yet to start messing with it on E85 as temperature seems to affect it.
With out seeing a log atm you may just want to put a little more fuel back in it where it goes lean in the cooler air.
Are you logging your runs? Mind posting a day and night run?
I am still working on understanding SD with 93, I have yet to start messing with it on E85 as temperature seems to affect it.
With out seeing a log atm you may just want to put a little more fuel back in it where it goes lean in the cooler air.
I am still working on understanding SD with 93, I have yet to start messing with it on E85 as temperature seems to affect it.
With out seeing a log atm you may just want to put a little more fuel back in it where it goes lean in the cooler air.
I haven't had a chance this past week to mess with the tune, but I will b tweaking it soon. Will let you know how it turns out.
Newbie
Joined: Oct 2013
Posts: 65
Likes: 0
From: Broomfield
I had an issue where my tune went suddenly lean. I traced it back to the ethanol I was running. Depending on where I filled my E85 my WOT AFR would be spot on at 12 or a full point lean at 13. Turns out one station was running E75 or so and the other must be around E90. It can vary that much between stations.
^And that right there is why I test mine. But I have heard as long as its about E70 you are good, thats what TSComp has said anyways. I still test mine regardless that way I know what it is.
If you tune on e70 for a target AFR of 11.5-12.0, it give you leeway to when you get true e85. When you get actual e85 and your tuned on e70 with a target of 11.5-12.0, you'll be half a point leaner. I always go to pumps that have a minimum 70% ethanol. Most e85 pumps will say what their minimum content is. I stay away from the 51% ones and haven't had any issues.
Newbie
Joined: Oct 2013
Posts: 71
Likes: 0
From: sweden
Ethanol is much mor expensive to produce than gas. So often its e75 or even e70. It also contains sulfur. Its where you gte the hangover from.
The ethanol corrodes aluminium and resolve rubbers. You need teflon lines all the way, no direct contact with aluminium( make sure your fuelpump doesent have aluminum pump gears)
When you map on ethanol, it doesent ping untill its way, way too lean. It needs to be much richer then gasolene. It also reads different on your lambda, example 0.8 lambda = 11.8 on gas, 0.8 lambda on ethanol is 7.2. So it gets very rich when mapping after gas lambdas. My experience is that i need around 0.95 lambda at wot 30 psi 10.5 with a good combustion chamber, 83mm bore, and piston speeds around 27 m/sec. Timing would e 27-28.
Untill e85 is stabilized in production and sulfur free, ill stay away from it. The inconsistancy and quality is way too great.
The ethanol corrodes aluminium and resolve rubbers. You need teflon lines all the way, no direct contact with aluminium( make sure your fuelpump doesent have aluminum pump gears)
When you map on ethanol, it doesent ping untill its way, way too lean. It needs to be much richer then gasolene. It also reads different on your lambda, example 0.8 lambda = 11.8 on gas, 0.8 lambda on ethanol is 7.2. So it gets very rich when mapping after gas lambdas. My experience is that i need around 0.95 lambda at wot 30 psi 10.5 with a good combustion chamber, 83mm bore, and piston speeds around 27 m/sec. Timing would e 27-28.
Untill e85 is stabilized in production and sulfur free, ill stay away from it. The inconsistancy and quality is way too great.
EvoM Guru
iTrader: (50)
Joined: Mar 2006
Posts: 9,675
Likes: 132
From: Tri-Cities, WA // Portland, OR
Ethanol is much mor expensive to produce than gas. So often its e75 or even e70. It also contains sulfur. Its where you gte the hangover from.
The ethanol corrodes aluminium and resolve rubbers. You need teflon lines all the way, no direct contact with aluminium( make sure your fuelpump doesent have aluminum pump gears)
When you map on ethanol, it doesent ping untill its way, way too lean. It needs to be much richer then gasolene. It also reads different on your lambda, example 0.8 lambda = 11.8 on gas, 0.8 lambda on ethanol is 7.2. So it gets very rich when mapping after gas lambdas. My experience is that i need around 0.95 lambda at wot 30 psi 10.5 with a good combustion chamber, 83mm bore, and piston speeds around 27 m/sec. Timing would e 27-28.
Untill e85 is stabilized in production and sulfur free, ill stay away from it. The inconsistancy and quality is way too great.
The ethanol corrodes aluminium and resolve rubbers. You need teflon lines all the way, no direct contact with aluminium( make sure your fuelpump doesent have aluminum pump gears)
When you map on ethanol, it doesent ping untill its way, way too lean. It needs to be much richer then gasolene. It also reads different on your lambda, example 0.8 lambda = 11.8 on gas, 0.8 lambda on ethanol is 7.2. So it gets very rich when mapping after gas lambdas. My experience is that i need around 0.95 lambda at wot 30 psi 10.5 with a good combustion chamber, 83mm bore, and piston speeds around 27 m/sec. Timing would e 27-28.
Untill e85 is stabilized in production and sulfur free, ill stay away from it. The inconsistancy and quality is way too great.
maybe you've just had bad luck.