Disclaimer: I make no claims that this will work for you or that this is even the right way to do this. All I can say is it worked very well for me on more than one case.
This subject is really an addendum to the tuning section listed in the E85 Sticky but it is a topic of much debate in the E85 community that I thought it should warrant its own thread. First let me say that my findings here are in no way conclusive and are still in the experimental stage. I am posting this now in the hopes of getting some of you to try these methods and report your findings to help further refine these steps.
I am finding the information regarding cold start issues with E85 in the Subaru community scattered and inconsistent. The RomRaider and E85 forums were of some help but the best and most reliable information came from our friends at EvoM forums. I was able to piece much of the information gained and form a solution for the Subaru community.
This experiment will be specific for RomRaider. All of this info comes from personal observations over the course of two years. Any input or insight to the subject would be Greatly Appreciated and no question is to dumb to ask.
***EDIT*** Cobb has updated the AP Firmware and AccessTuner Race. The procedure for this is the same as it is for OpenSource.
Explanations...
The reason E85 has trouble starting in cold weather is very simple. It does not evaporate at the same rate as gasoline in temperatures below 56*f and evaporates less and less as the temperatures fall from there. As a result you require more fuel during crank to compensate. However, too much fuel and you run the risk of saturating the cylinders to the point were fuel can no longer atomize properly and the droplets simply condense instead of vaporize. You need to find just the right amount because if the fuel does not atomize into a mist you will simply snuff out the spark and flood the cylinder.
To combat cold start issues thus far, methods have been employed that are no more than band aids. Things like block warmers and starter fluid and feathering the gas while cranking have all been employed but the best solution is to compensate for cold starts from with in your tune. With the following methods I have completely eliminated the need for block warmers and fuel heaters and any other hokey s**t.
Tuning concept...
RomRaider
In RomRaider there are tables for adjusting the Injector Pulse Width during crank as it related to temperature. This is fantastic because this is exactly the adjustment we have to make.
It is as simple as increasing the IPW for a given temperature, however the amount to adjust is still of debate. I will publish what I found to work for me but you really have to experiment with this on your own. You can probably use my numbers to get you started.
So to do this you want to open up your ROM in RomRaider and the tables for "Cranking Fuel Injector Pulse Width A,B,C,D" under the "Fuel - Cranking menu" Before you have access to modify these tables you need to change your user level to 5.
Once open, you want to increase the IPW in each cell from 68* and below. What I have found to work for me is begin to apply a 3% increase @ 68* and continue to increase the percentage from that point all the way to 30% @ -40*. See the below picture.
Now that gets us started but what about keeping us running. For that, you will find several tables under the menu for "Fueling - Warm-up Enrichment" called "Min Primary Base Enrichment" and "Min Primary Base Enrichment - Initial Start 2, 1A,B and 2A,B" You apply the same multipliers here as you did in the previous step.
That's it and it is that simple though the values must be discovered on your own. These may or may not work for you. It would be good if anyone has any personal findings regarding this experiment to please comment.
George.
This subject is really an addendum to the tuning section listed in the E85 Sticky but it is a topic of much debate in the E85 community that I thought it should warrant its own thread. First let me say that my findings here are in no way conclusive and are still in the experimental stage. I am posting this now in the hopes of getting some of you to try these methods and report your findings to help further refine these steps.
I am finding the information regarding cold start issues with E85 in the Subaru community scattered and inconsistent. The RomRaider and E85 forums were of some help but the best and most reliable information came from our friends at EvoM forums. I was able to piece much of the information gained and form a solution for the Subaru community.
This experiment will be specific for RomRaider. All of this info comes from personal observations over the course of two years. Any input or insight to the subject would be Greatly Appreciated and no question is to dumb to ask.
***EDIT*** Cobb has updated the AP Firmware and AccessTuner Race. The procedure for this is the same as it is for OpenSource.
Explanations...
The reason E85 has trouble starting in cold weather is very simple. It does not evaporate at the same rate as gasoline in temperatures below 56*f and evaporates less and less as the temperatures fall from there. As a result you require more fuel during crank to compensate. However, too much fuel and you run the risk of saturating the cylinders to the point were fuel can no longer atomize properly and the droplets simply condense instead of vaporize. You need to find just the right amount because if the fuel does not atomize into a mist you will simply snuff out the spark and flood the cylinder.
To combat cold start issues thus far, methods have been employed that are no more than band aids. Things like block warmers and starter fluid and feathering the gas while cranking have all been employed but the best solution is to compensate for cold starts from with in your tune. With the following methods I have completely eliminated the need for block warmers and fuel heaters and any other hokey s**t.
Tuning concept...
RomRaider
In RomRaider there are tables for adjusting the Injector Pulse Width during crank as it related to temperature. This is fantastic because this is exactly the adjustment we have to make.
It is as simple as increasing the IPW for a given temperature, however the amount to adjust is still of debate. I will publish what I found to work for me but you really have to experiment with this on your own. You can probably use my numbers to get you started.
So to do this you want to open up your ROM in RomRaider and the tables for "Cranking Fuel Injector Pulse Width A,B,C,D" under the "Fuel - Cranking menu" Before you have access to modify these tables you need to change your user level to 5.
Once open, you want to increase the IPW in each cell from 68* and below. What I have found to work for me is begin to apply a 3% increase @ 68* and continue to increase the percentage from that point all the way to 30% @ -40*. See the below picture.
Now that gets us started but what about keeping us running. For that, you will find several tables under the menu for "Fueling - Warm-up Enrichment" called "Min Primary Base Enrichment" and "Min Primary Base Enrichment - Initial Start 2, 1A,B and 2A,B" You apply the same multipliers here as you did in the previous step.
That's it and it is that simple though the values must be discovered on your own. These may or may not work for you. It would be good if anyone has any personal findings regarding this experiment to please comment.
George.