Windedv6
Ty n 10s
Re: what is needed for E85
You can not just fill your tank with E-85 on go drive. There is a number of things to be changed and really needs more than one tune setup.
I run E85 and have researched this to death. It does not like rubber lines. The neoprene rubber hose such as most braided hose is fine. Steel lines and tanks are fine. Aluminum fuel cells are fine if you don't leave them set partial full for the winter. Leaving E85 set in plastic fuel cans are fine for storage if not left in the sun. Paper filters are fine, but many perfer stainless filters. Some fuel pumps work better with E85 than others. The steel syty fuel lines are fine.
The down side of E85 is that you will need a complete retune of your AFR tables as the Stoichiometric air/fuel, weight of true E85 is 9.76 afr whereas gas is 14.7 afr. You will also have to run a fuel system that supplies aproximately 30% more fuel to equal the fuel amount needed for gas. That means larger injectors, larger pump and larger lines. E85 is not a goverment regulated fuel so not all stations may actually have E-85 as in 85% ethanol-15% gas. In cooler months most stations delute E85 down to 70% ethanol.
I run a GM flex fuel sensor which will read the ethanol content (realtime) and sends a signal to my FXI computer which makes adjustments automatically whether E10 (regular gas), E85 or any mix that is coming through the lines. If my tank is partially full of pump gas and I fill it with E85 the computer will make those adjustments in the Stoich and reset the tables accordingly.
Here is an interesting read that I had in my notes...
-----------------------------
SUMMER BLEND VS. WINTER BLEND
During the cold winter months, more gasoline is added to E85 by the fuel distributor before it gets to the station pumps. This is to aide in cold weather starting where ethanol vapors are less than adequate for starting conditions. For a true flex fuel vehicle there is a sensor that reads this ratio of ethanol and adjusts an internal ethanol table used to modify fuel and timing tables for proper fuel burn. With autos not currently setup with this sensor or the adjustable ethanol table one must be aware of what mixture is in the tank, in order to ensure the tune is correct for the fuel mixture.
The blend changeover triggers a change in the AFR because the ethanol percentage varies from 70% to 85% depending on the seasonal temperatures where you live. 70% ethanol content is the minimum percentage rating for Winter Blend E85. There is a middle grade (class 2) during Spring and Fall with a minimum of 74% ethanol. Summer Blend has a minimum of 79% but all variations are still called E85 for a recognizable common name. This changeover of blends varies per climate (NY goes to Winter Blend much sooner than Georgia).
The ethanol percentage changes are important to note because it changes the AFR, primarily at WOT when you're in Open Loop mode. (During Closed Loop or part-throttle operation, the O2 sensors report back to the ECU and tell it how much to modify the fuel flow.) How much does the AFR change? Our worst case projected scenario, is 1 full point on your gasoline AFR gauge. This represents the differences between 85% ethanol and 70% ethanol however the actual change between seasons is likely to be less than this. We want to ensure you understand the potential for seasonal changes.
With that said, let's look at what happens when going from one blend to the other... Let's say it's August and you're currently running a Summer Blend of E85 fuel. If your next tank fill-up were to be with Winter Blend, the car will go slightly more rich. At WOT, this is not dangerous, but could cause a performance impact if AFRs are not ideal. How much more rich? Well, that depends on the actual percentage of ethanol in the fuel you purchased.
Let's look at the flip side going from Winter Blend to Summer Blend during the Spring time. What happens here is much more important, because now we are going from less ethanol content (70%) to more ethanol content (85%) and that will potentially cause a lean condition. As we all know, lean is great on your wife or your grilled chicken, but certainly not on an internal combustion engine! As mentioned above, the maximum range it should fluctuate at WOT, is 1 full point on your gasoline AFR gauge. If you were previously at 11.8 AFR with the pedal to the floor, it could potentially go up as much as 12.8, but more likely around half a point at 12.3. When performance tuning, this could be a critical mistake that causes engine failure. The high octane is much more forgiving than gasoline but the longevity of your motor ultimately depends on how safe your tune was built.
During the transition months of Spring and Fall, it's even more difficult to know what class of E85 you're buying and testing your fuel as mentioned above is even more important. For the best results you will need two variations of the tune to load (winter and summer).
If multiple tunes are not possible, you're better off building your tune with Summer Blend (85%) and letting the car go more rich in Winter, so that you will be right on target again when warmer temps return during racing season.
--------
E85 is not regulated by the goverment under the same standards as gasoline so some stations may vary somewhat form the chart. It is commom to see the 85% minumin sticker (and allowable) at most stations. The octane rating will change with the ethenol content. True E85 is considered to be 105 octane. according to govermental standards. Here is a good read for most of the myths and facts that are out there...
http://www1.eere.energy.gov/biomass/ethanol_myths_facts.html
I run an aluminum fuel cell for E85. I never empty it or chase it with gasoline and have never had any problems. The myths that float around about e85 taking on a lot of moisture is played off of those running meth based alcohol which absorbs water easily. Ethenol based e85 is much less prone to absorbing water. It is better if you have a closed fuel system vs a open vented system. I mounted my fuel cell in the stock location and use the stock fuel fill setup with a vented cap that only lets in air if under vacuum.
Here is a link to the system most of the E85 guys use for setting up for flex fuel reading. This is what I currently use.
http://www.zeitronix.com/Products/ECA/ECA.htm
I purchased a new GM sensor, but used ones can be found. You can get new ones for $300 to $400, Used ones at a bone yard $50-$100. The problem with the bone yard stuff is unless you find it in a very recently junked auto, the sensor may be "junk" from old gas and other contaminates. You may be throwing your money away on a used one.
This gauge and sensor is just a readout for enthanol. Fast FXI is capable of using the GM sensor data in their program to adjust the fuel tables.
John
You can not just fill your tank with E-85 on go drive. There is a number of things to be changed and really needs more than one tune setup.
I run E85 and have researched this to death. It does not like rubber lines. The neoprene rubber hose such as most braided hose is fine. Steel lines and tanks are fine. Aluminum fuel cells are fine if you don't leave them set partial full for the winter. Leaving E85 set in plastic fuel cans are fine for storage if not left in the sun. Paper filters are fine, but many perfer stainless filters. Some fuel pumps work better with E85 than others. The steel syty fuel lines are fine.
The down side of E85 is that you will need a complete retune of your AFR tables as the Stoichiometric air/fuel, weight of true E85 is 9.76 afr whereas gas is 14.7 afr. You will also have to run a fuel system that supplies aproximately 30% more fuel to equal the fuel amount needed for gas. That means larger injectors, larger pump and larger lines. E85 is not a goverment regulated fuel so not all stations may actually have E-85 as in 85% ethanol-15% gas. In cooler months most stations delute E85 down to 70% ethanol.
I run a GM flex fuel sensor which will read the ethanol content (realtime) and sends a signal to my FXI computer which makes adjustments automatically whether E10 (regular gas), E85 or any mix that is coming through the lines. If my tank is partially full of pump gas and I fill it with E85 the computer will make those adjustments in the Stoich and reset the tables accordingly.
Here is an interesting read that I had in my notes...
-----------------------------
SUMMER BLEND VS. WINTER BLEND
During the cold winter months, more gasoline is added to E85 by the fuel distributor before it gets to the station pumps. This is to aide in cold weather starting where ethanol vapors are less than adequate for starting conditions. For a true flex fuel vehicle there is a sensor that reads this ratio of ethanol and adjusts an internal ethanol table used to modify fuel and timing tables for proper fuel burn. With autos not currently setup with this sensor or the adjustable ethanol table one must be aware of what mixture is in the tank, in order to ensure the tune is correct for the fuel mixture.
The blend changeover triggers a change in the AFR because the ethanol percentage varies from 70% to 85% depending on the seasonal temperatures where you live. 70% ethanol content is the minimum percentage rating for Winter Blend E85. There is a middle grade (class 2) during Spring and Fall with a minimum of 74% ethanol. Summer Blend has a minimum of 79% but all variations are still called E85 for a recognizable common name. This changeover of blends varies per climate (NY goes to Winter Blend much sooner than Georgia).
The ethanol percentage changes are important to note because it changes the AFR, primarily at WOT when you're in Open Loop mode. (During Closed Loop or part-throttle operation, the O2 sensors report back to the ECU and tell it how much to modify the fuel flow.) How much does the AFR change? Our worst case projected scenario, is 1 full point on your gasoline AFR gauge. This represents the differences between 85% ethanol and 70% ethanol however the actual change between seasons is likely to be less than this. We want to ensure you understand the potential for seasonal changes.
With that said, let's look at what happens when going from one blend to the other... Let's say it's August and you're currently running a Summer Blend of E85 fuel. If your next tank fill-up were to be with Winter Blend, the car will go slightly more rich. At WOT, this is not dangerous, but could cause a performance impact if AFRs are not ideal. How much more rich? Well, that depends on the actual percentage of ethanol in the fuel you purchased.
Let's look at the flip side going from Winter Blend to Summer Blend during the Spring time. What happens here is much more important, because now we are going from less ethanol content (70%) to more ethanol content (85%) and that will potentially cause a lean condition. As we all know, lean is great on your wife or your grilled chicken, but certainly not on an internal combustion engine! As mentioned above, the maximum range it should fluctuate at WOT, is 1 full point on your gasoline AFR gauge. If you were previously at 11.8 AFR with the pedal to the floor, it could potentially go up as much as 12.8, but more likely around half a point at 12.3. When performance tuning, this could be a critical mistake that causes engine failure. The high octane is much more forgiving than gasoline but the longevity of your motor ultimately depends on how safe your tune was built.
During the transition months of Spring and Fall, it's even more difficult to know what class of E85 you're buying and testing your fuel as mentioned above is even more important. For the best results you will need two variations of the tune to load (winter and summer).
If multiple tunes are not possible, you're better off building your tune with Summer Blend (85%) and letting the car go more rich in Winter, so that you will be right on target again when warmer temps return during racing season.
--------
E85 is not regulated by the goverment under the same standards as gasoline so some stations may vary somewhat form the chart. It is commom to see the 85% minumin sticker (and allowable) at most stations. The octane rating will change with the ethenol content. True E85 is considered to be 105 octane. according to govermental standards. Here is a good read for most of the myths and facts that are out there...
http://www1.eere.energy.gov/biomass/ethanol_myths_facts.html
I run an aluminum fuel cell for E85. I never empty it or chase it with gasoline and have never had any problems. The myths that float around about e85 taking on a lot of moisture is played off of those running meth based alcohol which absorbs water easily. Ethenol based e85 is much less prone to absorbing water. It is better if you have a closed fuel system vs a open vented system. I mounted my fuel cell in the stock location and use the stock fuel fill setup with a vented cap that only lets in air if under vacuum.
Here is a link to the system most of the E85 guys use for setting up for flex fuel reading. This is what I currently use.
http://www.zeitronix.com/Products/ECA/ECA.htm
I purchased a new GM sensor, but used ones can be found. You can get new ones for $300 to $400, Used ones at a bone yard $50-$100. The problem with the bone yard stuff is unless you find it in a very recently junked auto, the sensor may be "junk" from old gas and other contaminates. You may be throwing your money away on a used one.
This gauge and sensor is just a readout for enthanol. Fast FXI is capable of using the GM sensor data in their program to adjust the fuel tables.
John
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