Tuning help for E85

[95talonracer]

I am running 880 injectors that have a global setting of -46% and 330 dead time. What would I set this to if I tune on E85? Also I have a afpr and a 255 fuel pump so that should be good enough.

[scheides]

What turbo are you running? If it's not too huge, you should be good. What is your current IDC? This will be an excellent indicator of whether or not you have big enough injectors.

[Halon]

Do you have a wideband? You're going to need one to get your settings right on. Otherwise a good place to start is to add to your global, 30% from where it was. So if you're at -46 on 92 octane, 30% of that is ~14, so add 14 to your setting, which is -32. That'll get you started in the right direction, but still you're going to want to get it tuned with a wideband.

[95talonracer]

Ok. I have 880 injectors and a wideband. I have the aem wideband. What AF ratio do you tune to on e85? Do you do air fuel or limbada? Going to switch over tonight if I get all of the info I need. Thanks for the help.

[JET]

I have been reading that AF on the gas setting will end up around 12:1, some at 11.5 some at 12.5.

[95talonracer]

I know that but what about on e85 what will the af be?

[JET]

No, that was the AF reading for E85 if you just use the gas setting on the WB02.

[Halon]

On the Link forums, one of the guys mentioned that he aims for 12.0:1. He says he doesn't see much gains going any leaner then 12.5:1, so he stops at around 12.0 and then just starts adding timing instead of going leaner as he sees better results by adding timing at that point rather then leaning it more. He just adds timing until he starts seeing knock.

As far as Lambda, I believe you are just aiming for 1 no matter what your fuel.

[niterydr]

Originally Posted by Halon

On the Link forums, one of the guys mentioned that he aims for 12.0:1. He says he doesn't see much gains going any leaner then 12.5:1, so he stops at around 12.0 and then just starts adding timing instead of going leaner as he sees better results by adding timing at that point rather then leaning it more. He just adds timing until he starts seeing knock.

As far as Lambda, I believe you are just aiming for 1 no matter what your fuel.

.80-.85 lambda value usually gives you the most power/safety on MOST fuel types.
1.0 is stoich, good for cuising/idle

[Halon]

Thanks for clearing that up.

[95talonracer]

So if I am tuning for e85 at cruse it would be the same as gas at 14.7 and under full throttle it is also the same as regular gas at 12.0 or a bit less like 11.8 to be safe or is it different for the air fuel ratio for regular premium gas and E85 gas?

[carltalon]

Edit I found a simpler formula.

450/(new injector size * .77)-1

example 450/(880*.77)-1 = -.33....

[95talonracer]

How do I read that on my aem when it only goes down to 10.0?

[carltalon]

the wideband will read what the air fuel ratio would be for gas. you'll want between 12.0 and 12.5 on your guage.

[Halon]

Originally Posted by carltalon

Edit I found a simpler formula.

450/(new injector size * .77)-1

example 450/(880*.77)-1 = -.33....

Where'd you get that formula? I'm on 1600 injectors right now, and my global is at 52 I believe. That formula shows that I should be at 63. That would have me idling at an extrememly rich rate. I think I first started at 60, and at Idle I was seeing something like 18-19:1 ratio. At -52 I'm idling around 14:1 at around 1k RPM.

Also I'll note that my base FP is around 38psi.

[Halon]

Originally Posted by 95talonracer

How do I read that on my aem when it only goes down to 10.0?

Mine only goes to 10:1 too. I don't really see a need to have one that goes any lower. If your running richer then 10:1, you need to lean that baby out.

[tim]

Originally Posted by Halon

Where'd you get that formula? I'm on 1600 injectors right now, and my global is at 52 I believe. That formula shows that I should be at 63. That would have me idling at an extrememly rich rate. I think I first started at 60, and at Idle I was seeing something like 18-19:1 ratio. At -52 I'm idling around 14:1 at around 1k RPM.

Also I'll note that my base FP is around 38psi.

What are you using for a fuel pump(s)?

[Halon]

Single Walbro 255hp. Once I max it out, I'll play with lowering the FP, but eventually I'll just run a single Bosch 044 intank.

[95talonracer]

So you run a AF of 12.0 on premium normal gas and if you were to tune to E85?

[Halon]

Yes