for whats its worth i have a omni 4 bar map sensor and 12.8 made 35psi by 3800rpm almost dead on, and 13.3-13.5 didn't do it until 4100rpm. Maybe your wideband reads slightly different, but I figured i would just post real results here to give you an idea how the spoolup is effected by the a/f numbers. The spoolup is very picky and is about the hardest part to get dead on with the a/f tune thats for sure. This is pure e85 as well, actually slightly stronger.

let me add: I agree that 12.1 seems to be the area e85 likes the best. even goin from 11.8 to 12.1 feels different. 12.1 seems to be the spot where it makes max power


edit: this is interesting.. going over my logs again i see various a/f's at spool and the ones at 13.1 vs 12.8 vs even 14.0's all seem to be making 33psi by 3900. So I guess its not that picky after all. I think if you keep your a/f between 13-14 at spool you pretty much are good to go.

 

Temp, humidity, and baro all play in how the car reacts at various AFRS.

On Luke's car it was 25 ft lbs lost if he ran a 13.0 at spool vs running a 10.5. The drag car wont even pull through the converter if its leaner than 11.5.

My car seem to love 12.0, anything one way or the other and it tends to spaz out.

 

I noticed when I ran a richer mixture downlow between 4-5k i gained a good 30ft/lbs vs running it leaner like you just said. is it safe to run e85 in the 11.1-11.3 range Aaron? my car seems to like it rich downlow vs lean. Is it safe to run it richer throughout the entire powerband tho? and if not can you explain the logic in why its not good?

 

The only reason not to run rich is lost power. I have noticed Evos will really lose past 7k if they are "too" rich. What "too rich" is seems to be 11.0 or richer. The difference in power at various AFRs (this is all fuels that we have normal access to) is that there is only about 6whp difference from 11.0 to 12.0, no change from 12.0 to 12.7 and I dont normally run leaner than that but the few time I have tried running 13.0 it seemed to lose about 3whp (not averaged though). Leaner out the top (past peak power) seems to have less effect on power than before or at peak power. It can also be used to cure misfires in some cases. The leanest I have ever let an E85/E98 car leave the dyno is 12.4 out the top, 12.0 for the most part(mine).

By the way it was 13.0 on gasoline not E85 so it was interesting that there was no decrease in knock threshold either. I didnt leave it there obviously but it wasnt hurting it as much as I would have thouhgt. One 8 second pull on the dyno isnt a lifetime of street use or 20 min lapping sessions that lean either though.

 

Thanks, thats what I was looking for. It still pulls really hard uptop with richer mixture, but i did notice more pull with a leaner mixture up there. downlow it seems leaner is no good at all. Im getting a/f setup for Charlie so he can focus on timing only when on dyno. I think i about got everything perfect on the car finally if thats even possible with a mitsubishi

 

On my car I shoot for ~11.8 during spoolup/peek torque, and ~12.1 at peek rpm.

My car will see anywhere form ~11.5 during spoolup/peek torque and ~13.0 at peek rpm depending on how much my fuel pump likes me that day.

I have tried every AFR from 11.3 to 13.2. I found that my car is very happy in the high 11's, and as I go leaner the car will start to missfire more frequently.

Now that it is getting hotter out it seems that my car like to be a little richer. But I am always above 11.5 unless my o2 feedback freeks out and adds too much.

 

ya i tested it today. the car makes way more torque downlow if you keep it rich like high 10's low 11's. running rich after like 5k is pointless pretty much, i seen identical powerband but more injector duty.. so its like pissing e85 into the wind.. i will lean it out now so im not wasting e85. i was using 60% idc on 2150cc - whats that like 3mpg with e85?

 

I am going to log the afrs tonight but the initial feel with richer up to 5K felt much stronger seems to like low 11s much better than 12

 

You are using closed loop fueling under boost?

 

have you guys seen this thread - https://www.evolutionm.net/forums/ec...-table-17.html

is this maybe a cure for the a/f jumpage from night to day?

 

maybe

 

That table also affects load, while it can compensate for the temperature effect of E85 AFR, it will also affect what load cells are traversed. Not ideal, but can be used if willing to accept that it affects the load calculation.

 

So you guys believe it is better to run richer on spool (11.0~ AFR) or a bit leaner (12.8~13.0 AFR)??

 

Just keep it simple and aim for 12.0:1 for everything.

 

The problem is, I seem to have lost some spool since changing to e85.

So I was hoping on some tips and tricks to try and get that spool back to where is should be. It should be no later then 3,800RPM with a 2.3L + FP Black.