Need a -94 lt1 E85 tune

[scaryeyes]

oh... now i understand. Yes something is wrong here. Right side is a little lean. I looked at the histogram on the logfile i posted here. But that logfile is just on gas!
But the thing i ment were that when i used freescan yesterday BLM was 128 really stable. And so were it even today when i scanned after i filled up with 50% E85 and just changed the flow constant for the injectors.
Mabe im just paranoid here, im gonna scan tomorrow with datamaster, and then i have more accurate numbers. I dont know what conditions my o2´s are. Just one were new last year because of it broke i half during disassemble...
Im learning on the way here and i really thank for the info!

[scaryeyes]

And then we come to "beef up timing" Thats the tricky part, i understand.... I didnt learn at all of that one yet.

[n0dih]

If you have change injector flow and running 50% E85, you could be dead on, just got perfectly lucky too.

As for timing. Calculate your octane, see what you have in the tank and then add say a conservative amount.

So, take in tank octane - stock octane = lets guess 96 is in tank, and 91 is stock, that is 5, so take say 3 degrees and add it to the Spark Correction vs MAP vs Coolant Temp table overall. This will simply ADD timing without disturbing the detail of the stock timing table. Just makes a global update in timing.

Experiment with timing, you can add 5-8 degrees easily with full tank E85. Watch for knock. I ran as much as 12 degrees more timing in some areas (like 100 kPA and 2400 rpm) on my LT1 (Iron headed) and had no issues with ping at all. The LT1 is a GREAT engine for E85 with the high compression. I got an average of 15-17 mpg city/highway with E85 in a 3.42 geared Fleetwood that ran awesome on it..

Originally Posted by scaryeyes

And then we come to "beef up timing" Thats the tricky part, i understand.... I didnt learn at all of that one yet.

[n0dih]

Don't be worried, the OBD1 PCM is very forgiving, the PCM can handle it fine. The LT1 is one of the most ideal engines for E85 with the compression. Worry not!!! Dump it in 100% and go!

Originally Posted by scaryeyes

oh... now i understand. Yes something is wrong here. Right side is a little lean. I looked at the histogram on the logfile i posted here. But that logfile is just on gas!
But the thing i ment were that when i used freescan yesterday BLM was 128 really stable. And so were it even today when i scanned after i filled up with 50% E85 and just changed the flow constant for the injectors.
Mabe im just paranoid here, im gonna scan tomorrow with datamaster, and then i have more accurate numbers. I dont know what conditions my o2´s are. Just one were new last year because of it broke i half during disassemble...
Im learning on the way here and i really thank for the info!

[scaryeyes]

Thanks. Its very interesting! The followoing weeks im gonna fine tune it, and thanks for good and fast tips here!

[scaryeyes]

I have now a logfile with full tank 100% E85 and just changed the injector flow rate.
Im a little worried because both sides are not even at all. Then I found differences in the table "Individual cylinder fuel trim multiplier"

Can it have something to do with that??

[Team ZR-1]

Before worrying about using E85 you need to solve the basic problems

Some imbalance

CELLS LTFT-Avg LTFT2-Avg
C1 -5.49 3.05
C2 -4.87 3.10
PE3 0.00 2.30
C5 -3.81 0.07
PT6 -1.60 3.21
PE7 0.00 0.00
PT9 0.00 0.00
PT10 -1.60 0.04
PE11 0.00 0.80
PE14 0.00 0.00
WOT15 0.00 0.00
PARK16 -2.30 1.60
ACI17 -3.90 0.09
ACI18 -4.70 2.15

Issues are

1. injectors getting wacked out, as much as 98% duty cycle at around 35 ms pulse width on times.

2. out of fuel by 5200 RPMs
3. while timing at WOT as high as 38 degrees
4. IAT needs cooling down as hot as 120 degs, average was 103 deg
5. not eating a lot of air, about 450 CFM


Your not going to get away with using E85 that requires more fuel for the same output as normal gas, cylinder temps will be too high so need better flowing injectors or higher fuel rail pressure

[scaryeyes]

im searching for bigger injectors now. And i have a pressure regulator in my garage... maybe it can work in the meantime.

[scaryeyes]

I just watched the logfile i did on gas.... From 10th may i posted earlier here in this thread. Seems my stock injectors are little too small even for running stock. 83% at 5700 RPM. Maybe i have a lot to update in my car before i start to understandin the tuning. Have some hardware to replace i can imagine

[Team ZR-1]

Check the fuel rail pressure and see what it is, if it has an adjustable fuel regulator then raise the pressure to allow injectors to flow more volume.

In any case anytime injector pulse width is over 18 mSec or 80% duty cycle at mid to upper RPMs it has to be corrected even if engine is stock but surely then is too small for any performance gains or using E85.