JohnC

Tuning LS3 for E85

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Someone else looked at my logs and said this:

Outside of power enrichment it looks pretty good, commanded and actual are staying very close and the fuel trims are doing good.

But in PE the commanded lambda and the actual lambda aren't jiving right now. The EQ ratio still looks factory and that's really fat and your widebands are both reading leaner than the commanded.

You are running the MAF currently so add to the MAF curve above like 7,000hz ish to richen the fuel mixture to match your commanded target. Try like 2-3% at a time to add little by little to get close to the target EQ. Once you are there then you should take your entire power enrichment EQ ratio and lean the whole table out. On E85 or the mixed blend you are running you should totally be able to command a 12.5 or so AFR or .85 lambda. (up to the user if they wish to run leaner later on). Remember you have both a regular EQ and alcohol EQ you should adjust. 

It really shouldn't take much tuning to dial in the rest here. You can also create a lambda error for this as well and it help you just as well for dialing everything in.

Whatcha think?

You haven’t tuned your wot yet? I figured you would do that as soon as your widebands were installed. I wouldn’t tune to 12.5 afr on e85, that is lean. If you switch to lambda however .85 is about right.

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I tried to log fuel pump duty cycle, but evidentially, HPT has a bug where most folks report their logs show the pump stuck at 99.6% DC.

Mine is doing the same.

Trying to figure out how to fix that in HPT.

Deleting and adding it back to the scanner doesn't fix the issue. :no:

Is it showing as a polling or broadcast channel? And have you licensed the fpcm?

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Yes, I tuned WOT for 93 pump gas.

I have not done any AFR tuning for the E85.

The quote I posted was from HPT forum. A guy looked at my tune and logs and posted that.

I log in lambda. I have my gauges set to lambda also.

Is there anything else I need to do to get correct AFR for E85?

Polling or broadcast? How do I tell? 

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you are getting tip in knock even in drive mode. Sport/drive use the same timing maps so that will have nothing to do with your issue. If you watch your log, and slow down the playback speed, every time you give it some throttle you go rich and get knock. Commanded lambda is 1.0 and you are getting .77-.80. Short terms kick in and lean it out and knock goes away. You haven't tune wot, your commanded/actual is way off. Remember tuning in lambda 1.0 is 1.0 regardless of the fuel type you are using, that's why you tune in it. You want .85 under pe, which is almost where you are at, but your commanded is asking for .78 from where I "raped" your pe before you had a wideband. Now that you have one you need to fix it so commanded=actual. Adjust the flex fuel spark tables I attached, this will add a total of 4 degrees on 50% ethanol and above, Log for knock. I also attached the math/graph for a eq error. Your actual lambda under pe is ok if you want to try the timing changes first, but you need to fix it. 6300-6900 you need to add about 4%, 7050-7500 about 7%, 7650 and up 8%.

12636.jpg

12635.jpg

12678.jpg

eq ratio math.jpg

eq ratio graph.jpg

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Crap, so I add that % to MAF not the area I just did it..... :wall:

Yes. The only pe value you will mess with is gas AFTER your commanded=actual.

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23 hours ago, gammey4 said:

And are you logging flex fuel timing adder in your channels?

I think that is logged under Flex Fuel Advance.... Correct?

If so, then yes, I am. :up:

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I think that is logged under Flex Fuel Advance.... Correct?

If so, then yes, I am. :up:

Yes that is it. I didn’t get a chance to look at your logs last night. Your tip in knock is more than likely related to your untuned vve table. Even though you are in maf only it still get referenced for some transient fueling. Tackle that another day. What is your scanner showing for total sae timing at wot? Example 5,000 and cylinder airmass around .76 and up.

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Would that be timing advance sae?

If so, that depends on which area of wot you look at. I see 26 at the peak rpm mostly in sport mode.

Lower rpm wot, it can be 41 to 50.

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power enrichment eq ratio gas and alcohol needs to leaned out to .85. 3,000 and up change it to 1.195. that will give you a commanded lambda of .83, close enough for now. 1/eq ratio gives you your lambda. lean it out, scan for knock, and let me know. shouldn't have any, timing is pretty conservative.

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Changed it. Will have to get a new log...

Just fyi, here is where the gas is and alky was:

e85_pe_eq_ratio_vs_rpm.jpg

gas_pe_eq_ratio_vs_rpm.jpg

I know, I looked at your tune last night. When are you getting injectors? I’m sure you noticed but you are maxed out.

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3 minutes ago, gammey4 said:

I know, I looked at your tune last night. When are you getting injectors? I’m sure you noticed but you are maxed out.

I had a setback on injector money.

Cracked tooth went abscess, so I got to fork over $2,200 for a root canal and crown after insurance.

So I'm going to limp by for a little bit. :meh:

 

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I was $0.10 off per gallon on my fuel saving estimation.

E85 on a 350 mile trip will run me $47.32

93 pump gas will on a 350 weekly average will cost me $63.00

So E85 at my worst mpg average saves me $15.68 a week over 93 pump gas.

 

 

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