LNF Full E85 "Almost How-To"

I had about a gallon of 50/50 in the tank so i filled it up with straight E. On my tune I used my gas Maf tables, added 30% to the injector constant, bumped FP to 18.62MPA "2700psi" and lowered the boost DAls to 230 in the right collumn along with a slight reduction in the mid range in WGDC. Loaded it and the car ran okish... STFTs were all ove the place and LTFT were set between -14 and -16 after 15min log "found out I did something wrong in my math lol". I still havnt been able to get the PID to work for injector constant so I Multipied my -14 by my Current INJconstant and came up with my actual that i ran for this log which was 0.03651. Car ran exceptionally better, Had a few minor rich swings and the AFR was a little bumpy but didnt show any big problems! So... may be old news.. but your LTFTs have a direct corelation to your injector constant. I believe my max boost seen was right at 20-21ish. So my question is... What way would people recommed fixing the STFT sways and spikes? Through the injector constant? Cause its sitting at .8 dead. Or use Maf Correction from this point? Others have more insight on this so im asking your opinion. Any other pointers appreciated if im am off the wall somewhere:crazy:

There is a half decent pull in third of me easing into it at 2827

Just got back from a 2 hour long drive, traffic, freeway and some WOT pulls. STFTs are a little bumpy at times but closer. LTFT stayed at .8 sometimes dropping to 0 at times. Raised the DALs to 255 on the right column maxed my wastegate controls out again and bumped timing to 25.5* from 4k up and 23* from 3k. Car has a cleaner AFR and pulls smooth/HARD all the way to 6750rpms. I think this is the smoothest my car has ever ran!.... equivalent to stock..:)

NICE! Congrats on running full E85! I'm gonna check out your tune as I've been running full E85 but I've had some minor issues with power at the low end.

#1: You need to be logging fuel rail pressure, IDC and IPW or you are wasting your time.

#2: I found I needed more Inj Constant then 30% to run Full E85 with more boost on a bolted car.

#3: WAY too much fuel pressure. Im running full E85 w/26psi and 2200psi MAX fuel pressure. in fact, I run 1750 to about 4500rpm then ramp up toward the peak. You really don't need much.

how are you ramping FP at a certain rpm? I looked into adjusting Fp that way but couldnt figure it out. Are you using ramp limit positive? i thought that table would only work with fuel mass mode....then again you could use fuel mass mode lol. I would like to get this dialed in right. It runs good right now but i do get a few misfires if i create a instant hard load with a boost spike in third gear. If i run it all the way through second and third gear it has no problems what so ever.

Look at the Fuel Pressure table ;) IDK.. lol. (sorry, but it's obvious)

Yea i had a major brain fart there lol... for some reasonn i thought the tables were controlled by different pressure types... lol thank you for the smack in the head!:crazy:

Np :)

Dont forget that the injector constant histogram assumes that the tune was dialed in near perfect when on gas.

Ok, changed Stoich to 9.85,Reset fuel trims and have posted some logs
Note:
1. Very good low to mid power
2. Lower motor temps
3 .No WOT yet...

Any input from member on logs will be outstanding :)

Thanks,
Mr. 2008 SS

Quote:

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Originally Posted by Leafy

Dont forget that the injector constant histogram assumes that the tune was dialed in near perfect when on gas.

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Can you please post your histo for Injector constant. I have tried 1,142,353 different ways to get this to work and it is still not working right. Right now i have a custom PID and the filter being [0.03266]*[SENS.116] then just 200 in the X axis. tried coolent temp in the x axis and a million other ways.

wouldnt you want to set your Fuel Pressure positive ramp limit table to 1s in the right column to allow for the FP to react faster? possibly smoothing it out also and leaving low rpms alone? or am I wasting my time?

Would this be considered a good 'how to'?

I would like to try E85 and it would b great to have a point to start from.

Should MAF tables be increased by ~30% or is it best to increase injector constant?

Quote:

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Originally Posted by rian_human

Would this be considered a good 'how to'?

I would like to try E85 and it would b great to have a point to start from.

Should MAF tables be increased by ~30% or is it best to increase injector constant?

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Not really a good how too. I started it hoping that it would be a good thread for the LNF guys, but some cars seem not to like it or just wont keep up from what ive been seeing. I have 2 LNFs running on full E using this method plus injection timing tables, FP raised, and a few other changes. The car just doesnt like to see a massive initial hit in commanded fuel pressure. If you ease it into the higher pressure, control your boost spike and can keep inj duty cycle down then you pretty much have it. Like BYt said earlier in the thread it doenst take much fuel pressure but you will need more than 30% added to your injector constant. I know mine and others did. If you havnt tried E at all then i would suggest running a 50/50 mix first. you get close to the same power but dont have to worry about maxing injectors and other stuff. I guess the only up side to running full E on these cars is the littel extra torque you get and no mixing at the pump.

Pretty sure BYT modified injector angle tables and pulse width as well.

Although this doesn't go into the tuning aspects, take a look at this paper at MIT that does the analysis of using E85 on the LNF.

http://dspace.mit.edu/bitstream/hand...pdf?sequence=1