E85 question on set up

[jed344]

Ok I have had my fun on pump gas I'm ready to go to e85 now my question is I know I need 20-30% more fuel, so for cruse do I need to just adjust my global fuel % or accully go into the tables and add fuel. Wot tunning I am not worried about.

 

[LandSpeed-DSM]

Adjust your global for the fraction of ethanol in your fuel. If you are on V3 start with the Open Loop Target AFR and timing values you would use on pump gas (E0 or E10) and creep up on the tune from there.

 

[jed344]

I am on v3 and ok ill give her a shot. So In Essene lower global 20-30% then go into da tables shoot for 14.7 cruise and say 12.0 wot?

 

[97gsxIA]

Take your injector size (lets say for shits and giggles FIC 1050cc)

1050 x .670 (stoichiometric ratio of E85) = 703.5

703.5cc is what what your injectors will actually flow like on E85

so take stock injector size 450cc and divide by 703.5

= 0.639

now subtract 1 and you'll get your global fuel starting point to enter into ECMlink etc.

0.639 - 1 = -0.361 or -36.1%

I'm pretty sure the recommended deadtime starting point for FIC 750cc - FIC 1150cc was like 330usec but it might be more up into the 400's for E85 you just have to play with it based on your fuel trims

P.S. Cornfed from Iowa. DSM love!

 

[jed344]

Lol did u look at my mods list I am running fic 1050's. Do I need to set the stoich mixture target from 14.7 to 9:3:1 aswell?

 

[97gsxIA]

No, you'll use the same 14.7 AFR target value.

When people switch it in link and on their widebands to show 9:1 its just for true data values concerning E85.

In this case its keeping things relative to what youre used to as well as keeping it simple.

Tuning for 12-12.5 at WOT would be a great target on E85

Remember to gap you plugs closer (.24) as E85 requires a hotter spark.
Getting hotter plugs isnt a bad idea either although Brpe7s are just fine.

And no I didnt see that in your modlist, but that's what I'm also running so I figured why not use it as an example. If you upgrade to a holset you might want to think about even larger injectors. afterall theyre pushing much more fuel now

 

[jed344]

I'm running 6s gaped at .28 ATM think I should swap to 7s?

 

[Mark4g63t]

Yea. You should be fine with 7's.

 

[MY1GDSM]

FIC 1150cc was like 330usec but it might be more up into the 400's for E85 you just have to play with it based on your fuel trims

While the Math is "right"

You shouldn't be changing the deadtime. There may be a very slight difference in the specific gravity of the Fuel. But not enough to warrant a latency change.

Also most of what has been posted can be found in These two threads, OP.

Basic beginner questions HERE and Advanced discussion HERE Some of that is oldr so use comman sence and keep in mind some of it should be taken with a grain of salt. So to speak. But plenty info to go threw and get info on switching there.

YFI,
Real world the math doesn't always quite work... But is not a bad starting point. Just something to keep in mind.

 

[97gsxIA]

MY1GDSM is very correct.

Although the math is solid, usually there is 9-11% in standard deviation due to variations in fuel systems as well as variations in E85 mixture (typically whats in season)

Everything I said above for dialing in injectors is strictly a starting point. My setup was about 6% off after starting here.

Good luck man! You're gonna love not seeing knock in your tune

 

[jed344]

On average how long can a tank of e85 in my car be ok before it starts to go bad? I really hope so right now im stuck at 22psi at 10deg of timing due to knock...

edit: can i use the fuel filter in my fuel lab fuel filter for the time being just switch it out soon?

 

[97gsxIA]

It depends on how much is in your tank and how humid the climate is. The more air in the tank, the more moisture the gas will absorb from the air. If you plan on letting it sit add some of this stuff:

Deprecated Browser Error
It says browser error.. but the link works for me. try it out. its called Ethanol Sta-bil

Any typical fuel filter is fine even OEM. The facts on that miyth is simply the fact that E85 will clean your tank and all that gunk will come up through your filter and your injectors. Hence the "black goo" talk.

Just change the filter after your first few tanks and every so often take your fuel rail off and wipe the goo off your injectors.

 

[jed344]

Ok I feel like I'm ready to give it a shot one last thing on e85 what common timing at max torque?

 

[bastarddsm]

I find it's closer to 25% for me. I like to set my entire map to 12:1 and turn off closed loop. Then get an idea where things are to tune my global and maf comp.

Then 15:1 at cruize, and 13:1 at wot/0boost down to 11.5:1 at 20psi for me. More fuel makes more power, but wants more timing.

Spark plugs I'd run 8's probably. Timing, your gonna be 15-22* depending on boost and RPM.

 

[jed344]

Ok ill pry play it safe for now shoot for high 11s af and 17 timing at the end of rpm till I can get it on a dyno

 

[jed344]

Just went e85 quick tune 24psi 12 af and 17deg timming by 7k rpm it is a hole new animal im amazed by the difference and 0 knock.

 

[bastarddsm]

Told ya. .

 

[boost97gst]

Grab an e85 tester on ebay. Cheap and itll help you with your globals. For instance the place i buy from lists e85 but actually it tested at e75. Now that really doesnt make a WHOLE lot a difference. Most of us wouldnt notice. However if you test from different stations you can tell which one is the highest and use them. Trial and error. Grab 3 or 4 gallon cans and make a trip from place to place and mark the cans. Test em when you get home. Thats my plan. I have about 4 stations within 15 miles though so its fairly convenient. There are places ive heard of that are total dicks and sell junk like e60 thats labeled e85. no bueno.

And of course those plug n play conversions are meant for actual e85 so you may want to get crazy and add global if, say, your running e70. Just pullin this outta the air but if you were coming up with -40 lets say for e85 and you were actually getting e70 you might want to bump that up to -44 and give it a shot. Thats doing no math at all so dont jump on me, im just making a point.

 

[jed344]

Right now im at -35.9% and its close just little more adjustments

 

[97gsxIA]

I like to set my entire map to 12:1 and turn off closed loop. Then get an idea where things are to tune my global and maf comp.

Before this thread goes prehistoric, I just wanted to advice bastard's way of finding your global fuel settings.

Found out the hard way when I started going WOT and I was running 11 AFR when I was targeting 12.1.

This way you know for sure it's dead on.

 

[bastarddsm]

yeah, I like to set the map flat and sneak into boost. Easier to tune to a flat line than different AFR at different loads.

When I run a maf a few trips into boost in high gear and you;lll get her close.