outo, the concenses of opinion is to leave the wideband set for gasoline, as all the AFR numbers quoted have been measured that way.

this is just to save confusion though - and so we are all talking the same thing.

 

Are all E85 from state to state similiar?

 

Depending on the season the ethanol blend will be different between states...I know I saw a graph somewhere on here that had a graph of what blend during what months each state had.

 

One off topic question

can you run E85 on the 93 tune? untill you get tuned?

 

NO! Do not put e-85 in your car until your tuner is ready to tune it.

 

The short answer is NO... However, as long as you do not boost on E85, it is possible to use. It is strongly advised not to run E85 in your Evo until your tuned for it as TxEvo8 already stated. There is nothing to gain prior to tuning and everything to lose.

 

Just made the switch myself. The car loves e85. My setup is similar to the OP. I will post some results and such in a bit once I dial in the tune.

 

Thanks staying on E85 tune..
Just scary...

 

I'd be surprised if the car ran well at all with a 93 octane tune and e85 in the tank.

Regardless, it's not best practice. It's best to load the appropriate tune for the fuel being used.

 

Just do what most of us do. Make the ALT maps your 93 octane maps and your regular maps your e85. Or vice versa.

Then if you are every in dire need, you can make the car run in either condition.

I used my intercooler spray button as my switch. Works like a champ. You know you are on the ALT map because the IC spray light flashes. Tephra out did him self with it.

 

I think i just got some E70 in my tank, its only september.
knock counts were up, had to reduce boost.. anyone else run into these problems yet?
I might have to invest on the E85 gauge...

 

define knock counts are up?

are u usually getting 0-2 counts on e85 and it was higher than that?


if you are normally pushing 37 psi on e85 relatively safely, then the documentation i read must have been true that the 'octane' equivalent rating of e85 is more like 110-112 than it is 105.


Also, so the knock counts were up in september (which will still relatively warm), do you foresee that even with e70, u can raise the boost back up when the ambient temps are closer to 50's average?

 

i know this post is 2 years old, but i'm just now getting into this thead, and someone might be able to make use of this information.

Although I'm not sure what limits people have pushed with running *as much* boost as they can on *as high* a CR as they can, but i do know that for naturally aspirated applications, people have pushed their CR's to close to 16:1 on e85 with NO issues.

with news like that, I can't help but wonder if one could have their cake and eat it too. Since raising the CR generally improves torque, response, and most of all efficiency all the way around (including fuel), it'd be awesome to actually be able to not only fill the gap between MPG pump 93 and MPG e85, but to actually exceed it...to get better fuel efficiency on e85 than gasoline simply by running a compression ratio higher than you would *ever* be able to pull off with pump 93.............and then run boost on top of that.

Albeit it would have to be alot less boost, so people wanting stupid big power (600+) would probably not need apply. I would love an insta-spool 420 awhp/420 awtq evo with a **** ton of power under the curve and gets 38+ mpg on the highway, even if that 420 represents the most i could ever have because i couldn't run more than 12-14 psi on some fairly big turbo running 13:1 compression

 

I like your thinking. I would love to bump the gas mileage as well and make power. However I wouldnt go that high of a compression most likely 10:1 or if any thing changes information/technology an 11:1 max.

 

i can TOTALLY appreciate your sense of caution and safety, since engines aren't exactly a dime a dozen and the wallet pimp slaps anybody who turns their engines into a pile of molten magma.

However, e85 is hella resilient, you have to think big in order to ensure that the effort is worth it. If you look at the situation without boost for a second 10:1 and even 11:1 is still within pump 93 comfort zone.....corvettes and hondas do it all the time. You would need at least 12 or 12.5:1 to begin to take advantage of e85 where pump 93 will more than likely fear to tread (as far as everyday driving).

Well now the concern is boost...with such a high CR how can somebody run any amount of boost that's worth it. Well even though this is a very unscientific analogy, hopefully you will see the point i'm trying to make. If e85 can sustain naturally aspirated performance applications up to 16:1, and at 12.5 or even 13.0 you're 3 or more full points down from that, it would seem to leave alot of room open to replace with boost.

Example..at 10.5:1 most hondas won't run more than about 8 pounds of boost.....MAYBE 10 if their ballsy and throw caution to the wind....yet 2 points down to 8.5 and 8.8, evos are running 24 psi no problems (I know there's a crap ton more involved with this analogy, like head design, but just go with it). Having said that, more than likely even at close to 13:1 on e85, you will probably still have enough safety left to run over 10 pounds of boost, probably close to 15 (although i think that would be a stretch). I'm willing to bet that at 56ish MM turbo running on a 2 liter with 13:1 compression is going to produce 420-440 awhp with no real issue (remember, we're not shooting for huge power, just solid amounts of respectable street power in the sacrifice to reach pretty high MPG). I'm sure spool would be ridiculous....normally at 56, 58, or 61 mm turbo can be fairly lazy on the spool, but if u take into account a 13:1 CR and good ole e85, I'm sure spooling is quickened by a fairly large margin, probably enough to bring it back down within street driven reason.

In the end....the possibiliy of getting over 35 mpg, maybe even closing in on 40 mpg if ur a decent hyper miler on the highway, and pumping out close to 450 awhp when u need it...dude...i'm down.

By the way i haven't even mentioned meth injection for those short bursts of fun...if that's the case the sky's the limit...run a healthy meth nozzle or two...get 38-40 mpg on the highway and run 24+ psi on said 56 or 58 mm turbo, and go ahead and make 500+ awhp with a crap ton of power under the curve.

'Tis the future...and I'm excited.