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Discussion Starter #1 (Edited)
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.
 

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I am going to make an attempt perhaps this weekend to solve my issues with this annoyance. 40 degrees out and I am cranking for at least a minute to get started. I have an accessport and Tim Bailey gave me all my tunes in racetuner (?) format so I could modify them if needs be. I think the time is now.
 

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That worked awesome!! I used the same multipliers you did on all 8 categories. 40 degrees outside and she fired right up no problems like before!

Thanks a ton for sharing this info! Now my starting headaches are gone. :D
 

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Discussion Starter #6
That is great!!!

I'm so happy to have confirmation!

You might find that you may have to tweak the numbers a little more between 32* and 68*. These may need a little more. Ultimatley I ended up at 20% over stock for 68* and 50* and 30% over stock for 32* and under.
 

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I used your numbers to a tee. The problem was figuring out celcius versus fahrenheit.

So far it works great. It does need a bit of tweaking. Perhaps less fuel in my case around the 50 degrees fahrenheit mark.

If I tap on the pedal repeatedly while cranking she fires right up. Much happier with that versus the engine not popping off for over 30 seconds of cranking.

Thanks for posting this.
 

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For those that don't have stock injector sizes, don't you need to compensate the stock tables by the percent change in injector size first before making these suggested changes?
 

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For those that don't have stock injector sizes, don't you need to compensate the stock tables by the percent change in injector size first before making these suggested changes?
You are in Texas, this issue won't affect you. :D

Seriously though, I matched my tables to the ones posted and it made a huge difference. Although not perfect it is about 300% better than it was.
 

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Discussion Starter #11 (Edited)
For those that don't have stock injector sizes, don't you need to compensate the stock tables by the percent change in injector size first before making these suggested changes?
Not for these tables... But you need to have already properly scaled your injectors and calibrated your maf.

These adjustments are subsequent of others and the 30% increase is in no way related to the 30% global fueling seen in other tables. To be honest the 30% increase here is arbitrary at best and you need to find the best amount for your setup and region.

Besides it would be safe to assume that if anyone is using E85 I would hope they have the good sense not to use stock injectors, so larger injectors are implied.
 

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I understand about the 30% increase of injector scaler due to e85 vs 100% gas. In my last post, I was only refering to scaling the stock cranking tables based on increase in injector scaler and e85 use. I was assuming these tables were dependent on injector size, but you are saying they are not. That would explain why my adjustments weren't working and seemed like I wasn't getting enough fuel. I tried your table values but reduced them by 20%(I believe you have 1000cc injectors and I have 1200cc injectors) and it was much closer to where I need to be. I think I will try your exact numbers tonight and see if it improves my starting. That will prove that these cranking tables are in fact not dependent on injector size.

This has been the biggest help I have found on this topic so far. Thanks!
 

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It was 28 degrees the morning and my battery went dead trying to get her started. I need to adjust the maps a bit. Will post results after some experimenting.

For my first trial I am changing everything to a 30% increase except for 50 and 68 which I will change to a 20% increase.

Will reflash today and post results tomorrow morning when I try to start her in 25 degree weather.
 

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Outside temperature was 30 degrees. The temp inside the garage was 36.

Check out this video I made this morning.

E85 cold start map rev2 - YouTube

Thoughts? More fuel or less? Definitely helped by adding more fuel on the revised map. Should I bump everything from 32 and below up to 40%.
 

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Discussion Starter #15
What happened! you had it working didn't you?

I would first try it with leaner mixtures first... say something like 15% over stock values and see if it improves or worsens. Then if it worsens I would go with increasing over current levels but I would do it in only 5% increments. Your getting close to saturation if you go much beyond 40% over stock.
 

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I thought I had it working until I tried to start it after it was sitting all week in my garage. I suppose it did not help that it was 28 degrees out.

I am going back to square one. The revision 3 map I made @ 40% is even worse than yesterday. I will start @ 15% like you suggested.

What's the deal with the car not staying running if I let off the pedal after it starts?? Also the constant dips in the rpms until it gets warm??

Todays attempt to start. E85 cold start map rev3 - YouTube
 

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I thought I had it working until I tried to start it after it was sitting all week in my garage. I suppose it did not help that it was 28 degrees out.

I am going back to square one. The revision 3 map I made @ 40% is even worse than yesterday. I will start @ 15% like you suggested.

What's the deal with the car not staying running if I let off the pedal after it starts?? Also the constant dips in the rpms until it gets warm??

Todays attempt to start. E85 cold start map rev3 - YouTube
The car dying after starting is probably due to either your after start enrichment or your injector scaler/latency and/or maf table settings at low air flow.
 

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I will check those settings out but I have no idea on how to fix them or even where to start.
 

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I found out today that here in Oregon we do not get a winter blend of e70 which is the majority of my problem. I am done messing with this. I ordered a block heater which is highly recommended by cobb for Oregon winters and e85. 50 bucks shipped on ebay. Will report back with success or failure.
 

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