I'm about to start tunning on e85 and I've read every e85 topic on this board. I just want to make sure this is 100% correct. If I use a wideband with a/f ratio's for gasoline (because my wideband is not adjustable) I tune for the same a/f ratio's as on gasoline correct?

 

Correct

 

Just learn to tune with lambda. Stoichiometric for methonal, ehtonal, gasoline or even diesel is 1.00

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dartanian &raquo;</TD></TR><TR><TD CLASS="quote">Correct</TD></TR></TABLE>




11.8 is 11.8
14.7 is 14.7

lol I was kinda confused at first too

 

i wanna bump this up.
a e85 pump JUST opened locally...about 60 cents less a gallon

i'm turbo'd; so I run a 11:1 AFR under boost/high load.

so are you saying that if i start running e85, i tune to the same 11:1 AFR while under boost?

and that its 105 octane..i can get more aggressive in timing and run more boost than pump 93 would allow?

 

Well, plain and simple your tuning lamda, and then the mathematical conversion into an a/f ratio.

If your car runs well at .78 lambda (11.5:1 on gas roughly), then tune it to .78 lambda on E85. The readout is gonna say 11.5:1, but the true ratio, since it's E85, is gonna be 6.9:1 or so. Real straightforward.

 

so to be 100% clear:

i fill up on e85 for the first time

start adding fuel until my AFR's shows 11:1 again on my techedge wideband.

then if the station swaps to winter blend..i'll notice leaner AFRs and need to add a bit more fuel to compinsate?

my techedge isnt setup to show lamda..but is my statement correct? to just keep the AFRs showing 11:1.



Modified by darrinbrewer at 10:30 PM 4/13/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by darrinbrewer &raquo;</TD></TR><TR><TD CLASS="quote">so to be 100% clear:

i fill up on e85 for the first time

start adding fuel until my AFR's shows 11:1 again on my techedge wideband.

then if the station swaps to winter blend..i'll notice leaner AFRs and need to add a bit more fuel to compinsate?

my techedge isnt setup to show lamda..but is my statement correct? to just keep the AFRs showing 11:1.
</TD></TR></TABLE>


lol..... yes.... kinda

I would image winter blend would make your car richer, as it has more gas/less ethanol, I would also take some boost/timing out in that case.

 

so now i gotta safeguard my setup by taking care of aluminum parts...like my BDL fuel rail and AEM regulator...correct? aluminum and e85 dont go together. i got AN fittings and stainless braided fuel line to the rail..hmmm

 

thats what they say, I have had E85 sitting in my rail/reg for 4 months now, and the other day I took the rail off and it looks normal, same for inside the regulator, both are AEM pieces.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by darrinbrewer &raquo;</TD></TR><TR><TD CLASS="quote">so now i gotta safeguard my setup by taking care of aluminum parts...like my BDL fuel rail and AEM regulator...correct? aluminum and e85 dont go together. i got AN fittings and stainless braided fuel line to the rail..hmmm</TD></TR></TABLE>

Over the past several weeks, I've worked many hours of research into E85, ethanol, distilling, atsm standards, storage, etc. The most common confusion is methanol versus ethanol. Methanol is HIGHLY corrosive to aluminum, while ethanol is hardly corrosive.

The best that I've seen, is that after many years of use there MAY be some sign of corrosion, but I personally think it'll take many years.

 

In my area, the shell will rot WAY before any fuel system parts will. You can find cars here with fuel tank leaks that started from the outside...

With E85 you can run it a tad leaner if you want, but you can also run it much richer. Gasoline starts dropping steeply in power below ~12:1 afr's, while E85 doesn't hit that point until ~.7 lambda, or ~10.5:1 afr's. Given that E85 will cool your intake charge more than gas will at the same AFR, running 11:1 E85 will be all that much cooler. A guy who;s done lots of testing since 2004 with his STi said that you can add a little more timing for the vacuum columns, but with boost you can add a decent amount extra.

In other words, swapping from 91+ to E85: Add a base 30% more fuel, add a little more base timing, and keep the same AFR's. Target 11-12.5:1 AFR's (based on power levels), more timing (based on dyno), you're golden. Ideally, you'd increase your compression ratio by ~1 point, and keep timing the same (barely any extra advancing).


BTW if you go to http://e85prices.com, they will show you reports on prices vs 89 octane. Most places that are 15% or higher spread will net you a better $/mile rating with E85 vs 93 octane. I'm thinking about doing an E85 d15b2/z6 minime for my beater, since it will be ~10:1 and get me better $/mile for fuel. And more power

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">

BTW if you go to http://e85prices.com, they will show you reports on prices vs 89 octane. Most places that are 15% or higher spread will net you a better $/mile rating with E85 vs 93 octane. I'm thinking about doing an E85 d15b2/z6 minime for my beater, since it will be ~10:1 and get me better $/mile for fuel. And more power </TD></TR></TABLE>

This was exactly what I was coming to in another thread. Given the steep cost of 93, on E85 I'm actually just about dead even yet getting a higher octane fuel out of it. I worked out the mileage pretty closely to be accurate, and if anything, over 300 miles I might be spending 3 more dollars with E85. With fuel rising though, that only gets better.