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E85 BF NA how?


adhdesigns
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Hi guys this might seem like wrongness but I would like to have a go at getting a NA Barra to work on e85. I've seen some guys getting e85 to work well with NA with other types of cars showing some performance gains (Always of interest - I'm sure - to us all.) I also have other reasons for getting this to work in my car.

I think that I understand what is needed to get it ready to tune. Workshop (one car), custom os, E85 sensor, e85 compatible pump.

What else do I need to get or do to make this happen?

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Technically you don't need one car workshop edition if you tune it fixed fuel. However a flex sensor is definitely a much better idea as you can do various mixes and avoid draining the tank when you want to go back to 98. 

If you replace the pump I recommend buying a kit with wiring and the cradle so you know everything is not going to fall apart. I'd also recommend changing the fuel filter, preferably a removable one if you are going to let the car sit as e85 will gum things up if left to sit. 

In terms of gains you can probably simply run full MBT timing at all times and call it a day. If everything else is stock there wouldn't be much more in it. 

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There are 2 main timing maps, Borderline Knock and MBT Spark.

Simply put the borderline knock table will do most of the heavy lifting and after various corrections the pcm will mostly use this table to give you a final spark number.

The MBT Spark table is supposed to be the maximum spark needed, after corrections, to make the most power with a fuel that prevents detonation.

You can't just copy the MBT table to the Borderline Knock table and call it a day. Just because a fuel wont knock, it does not mean that the flame propogation will reach maximum torque on the conrod at the same time as another fuel that also wont knock.

So to answer your question about what else you need to make it happen, you need to understand what you're doing as far as tuning it goes, and you'll need a dyno to accurately dial in the ignition timing.

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Hey so yeah you don't really need much more than the professional version to convert to E85. My wagon is na with e85 all on a stock fuel system and I've had zero issues whatsoever. Basically all you have to do is change the stoich ratio to suit E85 and adjust the cold start parameters to get it to start everytime 

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Thanks Puffwagon and Jay,

Very interesting and useful information I'm still wondering how the ECU decides when to pull timing? Is it just going to be slowly advancing/ retarding it's timing until knock is detected, repeat, repeat? How does WOT affect the timing? There must be a reasonable way to safely determine the best timing/ Vs torque for e85 Vs 98?

Jay I am wondering if you have any more to say about your experience with e85? How long have you been running your car on e85? Are you only running it on e85? Are you using a wideband to make sure of your fueling? Did you have to watch your knock detector? What are your thoughts on the whole experience?

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Ignore the question about spark I've just read the nfo: spark tables from Roland. Dyno time seems to be the best answer for this question. 

I would still like to hear from Jay and anyone else who have their NA on e85.

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Car loves it, mainly doing it for the cooling and knock resistance as the cars a street/drift car. No wideband whatsoever so no idea what it's doing but seems to be working great 

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Fark me I just wrote up some hectic info for you guys about na e85 tuning etc and the farken forum logged me out and lost the post. I ain't farken writing all that out again 🤬

But yeah a wideband is needed to make the most of what the fuel has to offer cos if it's pig rich it will lose power, same as too lean. It'll run fine tho and unless you're a matrix level tuna you won't even be able to tell the difference.

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16 hours ago, Puffwagon said:

Fark me I just wrote up some hectic info for you guys about na e85 tuning etc and the farken forum logged me out and lost the post. I ain't farken writing all that out again 🤬

@PuffwagonI know how frustrating it can be 🤣, I've had this happen a couple of times now. I usually know it's happened when I go to paste an image & it gives an error so I copy what I have written & then log back in & paste. The other thing that is a tell tale sign is if you have all the posts from the page showing in the post you are typing up.

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I can't remember exactly what I wrote but here's some of it... A na car will run over a massive afr range, from 9:1 up to about 16.5:1 and most people wont notice the difference just by driving it. At either extreme it will start to miss a bit and idling at 9:1 will eventually foul the plugs and it wont start again.

You want to aim for about 13:1 for max power on an na car, having it extremely rich or lean will lose power. AFR = air fuel ratio, it's the parts of air to parts of fuel. Although we don't particularly care about economy it is still important to have a car running as well as it can be. Sure you can run it rich and it won't matter but why waste fuel for less power than a leaner mix will make? Think about AFR as a percentage, 10:1 will use a farkload more fuel than 13:1, but as I mentioned no one can tell the difference except a very few people who do this stuff day in day out.

Anyhow this is why a wideband is necessary.

One more thing, a lean mix doesn't cause knock, too much timing causes knock. A lean mix will create more heat which reduces resistance to knock, but ultimately it's the timing that causes knock.

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21 hours ago, Bill said:

@PuffwagonI know how frustrating it can be 🤣, I've had this happen a couple of times now. I usually know it's happened when I go to paste an image & it gives an error so I copy what I have written & then log back in & paste. The other thing that is a tell tale sign is if you have all the posts from the page showing in the post you are typing up.

How often does this happen? I'll hit up Invision Community support. If you can reproduce it (probably not but if you can then they will be able to fix it) you can right click in chrome "Inspect" Go to the network tab, click preserve log. Wait for the problem to occur. Then right click "save all as HAR" and send it to us privately (as it has some of your login details in there) and we can send it straight to Invision. They usually patch it within days if they can reproduce it.

It is possible related to leaving the forum open, sleeping your computer, opening the same browser and clicking reply/post before its refreshed. We had issues with that and seeing a random JSON error which they did fix after we reported it.

image.png.1fbdaa599c3b1fddfcda4e8c0b4ed98c.png

image.png.bb257c9c48476cf5c1a6740d4dbacbd1.png

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This is more for turbo cars, but its about E85 and I found it interesting so I'll post it here as well.

People always talk about "rich detonation" or how running crazy rich E85 will lift the head. This goes against what you'd expect as crazy rich means less combustion pressure, slower frame front etc. However three things occur when you go too rich.

Higher compression due to extra liquid, its a tiny increase, but its still an increase.

Slow flame speed means more energy is converted to heat and less is converted to force, this means more of the energy goes into the cylinder wall than before. The extra volume does suck more heat out of the air though, unsure if it completely offsets the extra heat energy from the fuel though.

Slow flame speed means you need to massively advance the timing to make the same power.

If you plot peak MBT with optimised timing at 0.7 lambda vs peak MBT with optimised timing at 0.85 lambda, the 0.7 will be much higher and probably lower torque output as well.

Here is a plot of combustions pressure with water injection, the affect is very similar to running E85 and optimising timing as you are adding volume, adding cooling ability and slowing down the flame front.

You can see that the combustion pressure is higher, it occurs earlier, the heat released is higher and also occurs earlier, all of these things make detonation more likely, not less likely.

May be an image of text that says "Baseline without water Injection, SA= 3 CAD BTDC Water/Fuel= 0.33, SA= 3 CAD BTDC Water/Fuel= 0.33, SA= CAD BTDC 45 40 Baseline without -walerjnjectior- water 35 with'spark -advange- 30 vlna 20 15 Watec jojection. without spark advance 45 25 35 [KJ/CAD] 5 15 dQ/dCA 100 of mma Dumea 60 80 actlo 40 Mass 20 0 10 20 30 Crank Angle [CAD] 40 50 Figure 8. Effect of water injection and spark advance on cylinder pressure, heat release and MFB at 1000 r/min 8.83 bar NIMEP."

As you can see when you go too rich (and optimise your timing), your combustion pressure actually goes up, which you might not have thought about. So running leaner can actually make more torque AND be lower combustion pressure, hence safer.

PDF the image is from attached.

1468087419832791.pdf

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2 hours ago, Roland@pcmtec said:

How often does this happen? I'll hit up Invision Community support. If you can reproduce it (probably not but if you can then they will be able to fix it) you can right click in chrome "Inspect" Go to the network tab, click preserve log. Wait for the problem to occur. Then right click "save all as HAR" and send it to us privately (as it has some of your login details in there) and we can send it straight to Invision. They usually patch it within days if they can reproduce it.

It is possible related to leaving the forum open, sleeping your computer, opening the same browser and clicking reply/post before its refreshed. We had issues with that and seeing a random JSON error which they did fix after we reported it.

Hey @Roland@pcmtec I usually use FireFox as a web browser & as you have suggested, it is possible that it is related to leaving the forum open....I'm guilty. The other theory I had was it may be due to internet drop outs which is why I haven't worried about it too much something I've been fighting Telstra/Bigpond over for years. 

About 2 weeks ago, I installed Starlink Internet & gave Telstra /Bigpond the boot. It's amazing what a difference it makes having over 200Mbps download & 30-50Mbps upload. So far, I have only recorded connection issues when firmware updates are happening. They are usually about 3am so it doesn't count 🤣
I don't recall having the issue in the last 2 weeks so I'll monitor & send you some info if occurs again.

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Thanks Roland for that great article. Also your warning about going rich with the e85.

For years I've been reading other's observations that an engine works better on a rainy day and their subsequent attempts at replicating these results in various ways. It was interesting that they were able to identify that a ratio of 1:1 of fuel and water had excellent efficiency outcomes. I wonder if we could just put a piggy back ECU running a water injector into the intake manifold at this ratio would get us some good results? Or, perhaps a better choice, I wonder if one of the sensors in the car could be reconfigured as an output with the PCMTEC custom OS? This could be used to trigger a driver box running stand alone injector hardware.

Roland are you talking about this in a separate topic?

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So I've got my wideband going now. From the Injector scaling topic I've been able to fix an over-fuelling issue that was present due to a larger fuel-pump that I installed last year - with the bigger surge bucket that the FGs use (probably a good upgrade... if I had done something about the standard regulator at the same time - I asked the seller if the pump would affect fuelling, they told me not to worry, I guess they wanted to sell the product more than anything else).

I also am using a fuel pressure sensor and I included it in my datalogging - I would recommend this to everyone. What did I find? The standard fuel regulator and perhaps the hole in the return cannot keep the pressure down to the 2.7 bar that it is rated for. This was the case until about 80% throttle and over 2500 rpm. Then pressure started to decrease to the correct 2.7 bar after this - though not until 4000 rpm did the pressure get down to the 2.7 bar. The pressure did not drop past this pressure (the regulator is probably working ok for the normal type of fuel pump). Before these points where the car usually operates the pressure stayed at 3.05 bar. I've ordered an adjustable regulator and I 'm thinking of setting it at 3.05 bar.

Puffwagon and Roland and probably others that I have missed were able to point me in the correct direction (using the injector scaling topic) for how to fix the Low and High slopes. I guessed that the Breakpoint wont really change as well as the PW minimum as these are physical attributes that are related to how fast the solenoid moves. I used Puffwagon's idea of using LTFT to tune the slopes. Someone pointed out the the low slope will be fairly much the only thing operating at Idle and LTFT in this area was .95 so I increased (multiplied) the slope by 1.05 (5% more than standard). Now my LTFT are spot on in this area of the Map. After this most of the map (where fuel pressure is 12% over) with a LTFT of .88 - I scaled the LTFT by 1.07 (7% more) because the Low and High slopes are added to get the final increase. Guess what... Now my LTFT is basically spot on (1s everywhere in the map until fuel pressure starts to drop). Very happy. Thanks guys.

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That will do it. 

And it will also show what your injector data is like. There may be some wincing from the hard core, but a few to 5 percent adjustment of stoich here or there to get the trims back is ok IMHO. If you're having to rape it then something is wrong.

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58 minutes ago, hjtrbo said:

There may be some wincing from the hard core, but a few to 5 percent adjustment of stoich here or there to get the trims back is ok

 

I haven't said it lately but now seems like a good of time as any, you are tuning the car, not the computer. If the car is running the correct afr, the correct timing and otherwise drives fine then call it tuned. There is no point trying to absolutely make every detail match in the pcm to get a car tuned, unless of course you like the learning exercise.

That's not to take away from actually knowing what you're doing and doing things "properly" but yeah, a little bit of discrepancy here and there doesn't matter.

 

In other news the stoich value does nothing in some calibrations.

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23 hours ago, adhdesigns said:

Thanks Roland for that great article. Also your warning about going rich with the e85.

For years I've been reading other's observations that an engine works better on a rainy day and their subsequent attempts at replicating these results in various ways. It was interesting that they were able to identify that a ratio of 1:1 of fuel and water had excellent efficiency outcomes. I wonder if we could just put a piggy back ECU running a water injector into the intake manifold at this ratio would get us some good results? Or, perhaps a better choice, I wonder if one of the sensors in the car could be reconfigured as an output with the PCMTEC custom OS? This could be used to trigger a driver box running stand alone injector hardware.

Roland are you talking about this in a separate topic?

Yes it's definitely possible to do with the custom os. 

 

 

18 hours ago, hjtrbo said:

That will do it. 

And it will also show what your injector data is like. There may be some wincing from the hard core, but a few to 5 percent adjustment of stoich here or there to get the trims back is ok IMHO. If you're having to rape it then something is wrong.

On big boost cars is common to do this. Eg if you are running 18psi on 98 and 35psi on e85 you would normally have to fudge the slopes or speed density due a combination of a variety of effects. No more than a few % though 

 

17 hours ago, Puffwagon said:

 

I haven't said it lately but now seems like a good of time as any, you are tuning the car, not the computer. If the car is running the correct afr, the correct timing and otherwise drives fine then call it tuned. There is no point trying to absolutely make every detail match in the pcm to get a car tuned, unless of course you like the learning exercise.

That's not to take away from actually knowing what you're doing and doing things "properly" but yeah, a little bit of discrepancy here and there doesn't matter.

 

In other news the stoich value does nothing in some calibrations.

Completely agree. End of the day if the car operates in the range of conditions your require it to with acceptable timing, afr and safety limits then it doesn't really matter how you achieve it. The short cuts are often much simpler and more reliable than doing it "properly". It's also a hell of alot faster. 

Which calibrations do you find stoich doesn't work in? It should be used in all. 

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2 hours ago, Roland@pcmtec said:

Which calibrations do you find stoich doesn't work in?

It didn't do anything in my territory, HACH4A6/PCMA5A6. We spoke about it recently on the forum and you said you might consider removing it from the software cos it doesn't do anything anyway.

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1 hour ago, Puffwagon said:

It didn't do anything in my territory, HACH4A6/PCMA5A6. We spoke about it recently on the forum and you said you might consider removing it from the software cos it doesn't do anything anyway.

Ah right that is the custom operating system as Stoich is remapped to be used by the new ethanol stoich lookup system. So its still there, its just a 1D table instead.

To modify stoich on a Custom OS with flex/multi tune. Modify this table instead. auF100014

image.png.d630796288e8035e81a91533e18cd947.png

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On 4/14/2022 at 12:51 PM, adhdesigns said:

Now I'm considering (when I get my new regulator) what happens when I fill her up with e85. Can I just change the fuelling from 14.6396 to 9.733 in this section and see what happens?  

image.thumb.png.2ea87757cfa7927a7a8a6168fb07e3c1.png

when i had an abundance of leftover e85 from the race car, i ran my territory well into fuel light - filled up with the e85, changed AUF0117, changed startup timming and set my boost back to WG pressure 8 psi.

the boost dial back was me being overly precocious as i only have a 255 in it.

Car ran normal as expected. i did notice the throttle tip in was richer than needed, but for the sake of using up leftover fuel i didn't bother playing with it.

 

when i was ready to put 98 back in, let it go to fuel light, put 98 in, drove till the wideband started reading rich (only like 5 kms) then put the settings back.

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  • 4 months later...

So I gave it a go today after getting fuelling within .99 months now. It ran without much noticeable difference. It did run hotter though. Head temp was 10 degrees hotter and water was about the same.  Driving fueling was generally 1.05 Idle fueling was 1.10 but the wideband was showing the LTFT and stft were still on top of these.

I was surprised to see the higher temps because others have noticed a cooling affect.

If LTFT and STFT are working should the base map really need to be changed? If I did would I be likely to see the cooling affect that others have seen?

 

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Your thermostat is what keeps your engine at a steady temperature. Running e85 won't affect the operating temperature of a warmed up engine at cruise, if the coolant system is up to spec. It might take longer to intially warm up, but will still settle where the thermostat is set.

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