Fuel Tuning E85

Tuning The Delco In Realtime
VX L67 Getrag
Posts: 2877
Joined: Sun Aug 02, 2009 9:16 pm
Location: Bayside, Melbourne, Victoria
Contact:

Fuel Tuning E85

Post by VX L67 Getrag »

So I'm just setting up a car on E85 for the first time & as I wanted to make it simple to start with I left the AFR tables alone for now & just changed the injector rate by 1.5 & BINGO it fired 1st turn....

But although I haven't changed the AFR tables I know it's going to command 14.7 instead of 9.8 but shouldn't the wideband be reading 9.8 or there abouts?

If I had the wideband set for lambda no matter what fuel it was it should be 1 but I prefer AFR for now so not sure why the wideband is showing petrol based afr & it is a MTX-L by the way if it makes any difference (guessing it may be a setting I need to change in it?).

Does anyone have a base timing (off original topic I know) of what can be added for E85 over 98Ron for MAF, I've seen a couple of MAP based spark tables but not really relevant with MAF & not sure if they can be trusted.
User avatar
Gareth
Posts: 2505
Joined: Fri Mar 14, 2014 8:37 pm
Location: Bacchus Marsh, Vic

Re: Fuel Tuning E85

Post by Gareth »

You said MAF, but what sort of engine is it?
According to chemistry, alcohol is a solution...
User avatar
vlad01
Posts: 7780
Joined: Mon Oct 08, 2012 6:41 pm
cars: VP I S
VP I executive
VP II executive
VP II executive #2
VR II executive
Location: Kyneton, Vic

Re: Fuel Tuning E85

Post by vlad01 »

You have to change the 0-5V WB AFRs to the converted E85 ones and modify the ADX to display the correct range to suit and then it will all line up with the correct numbers.

Also there are a lot more tables you need to change to E85 values than just the target AFR tables and cranking pulses.

As for timing I found less up top and slightly more at bottom is what E85 likes over petrol.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
VX L67 Getrag
Posts: 2877
Joined: Sun Aug 02, 2009 9:16 pm
Location: Bayside, Melbourne, Victoria
Contact:

Re: Fuel Tuning E85

Post by VX L67 Getrag »

it's a VS L67 with VE maf!

wideband figure I'm talking about is on the innovate unit itself not the ADX.

Yeah I assumed there's a LOT of fuel tables to change for E85 hence why I just kept it simple for starters!

That sounds pretty crap about the timing up top for E85!
User avatar
Holden202T
Posts: 10311
Joined: Sat Feb 28, 2009 9:05 pm
Location: Tenambit, NSW
Contact:

Re: Fuel Tuning E85

Post by Holden202T »

as I understand it they all read in lambda and just you changing the display to e85/petrol etc just changes the calculation to what it displays .....
User avatar
antus
Site Admin
Posts: 8237
Joined: Sat Feb 28, 2009 8:34 pm
cars: TX Gemini 2L Twincam
TX Gemini SR20 18psi
Datsun 1200 Ute
Subaru Blitzen '06 EZ30 4th gen, 3.0R Spec B
Contact:

Re: Fuel Tuning E85

Post by antus »

Thats correct, different mixtures go in, same mixture in the result when you hit the right fuelling. Thats why lambda makes more sense, but once your used to petrol AFRs maybe you should just leave it and think in petrol terms.

If it was 11p or 12p you'd need to change the ms time on the cranking tables, and I think the AE/DE, but not sure how that applys to the MAF pcm.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
VX L67 Getrag
Posts: 2877
Joined: Sun Aug 02, 2009 9:16 pm
Location: Bayside, Melbourne, Victoria
Contact:

Re: Fuel Tuning E85

Post by VX L67 Getrag »

Ahh cool that all makes sense & yeah I think once we all get used to lambda it will be the easiest way to go!

Yeah I think to change the MAF based setups would be much the same as what you described for $11p & $12p.

Is the power enriched AFR baseline the same for petrol as E85 or can it run a little leaner under load?
User avatar
charlay86
Posts: 584
Joined: Thu Sep 17, 2009 2:00 pm
cars: VT S1 SS (L67)
Location: Perth, WA

Re: Fuel Tuning E85

Post by charlay86 »

You should actually be able to go leaner in many places, one of the advantages of using a fuel that has a lower equivalence ratio is that you have a higher density of fuel molecules available for a given lambda (Meaning there is a lower chance of misfire).
If you aren't knock limited (which you shouldn't be at high RPM), less timing is a good thing since you aren't wasting energy pushing the piston the wrong way!
User avatar
vlad01
Posts: 7780
Joined: Mon Oct 08, 2012 6:41 pm
cars: VP I S
VP I executive
VP II executive
VP II executive #2
VR II executive
Location: Kyneton, Vic

Re: Fuel Tuning E85

Post by vlad01 »

E85 burns faster under high load conditions so yes you will require less timing to get MBT. Best efficiency is where MBT is "Max brake torque" So that means lowest timing that yields the best torque is the best spot for efficiency rather than the higher end of the MBT plateau.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
VX L67 Getrag
Posts: 2877
Joined: Sun Aug 02, 2009 9:16 pm
Location: Bayside, Melbourne, Victoria
Contact:

Re: Fuel Tuning E85

Post by VX L67 Getrag »

found this in my searches it may help others...

http://www.evolutionm.net/forums/e85-et ... notes.html
Post Reply