Ok who's running E85

Hey guys, so let's talk E85, I'm currently running it and was just woundering what you guys are seeing for A/F ratios or Lambda, on my logs I've been looking at I've seen .80 to .85, if I'm doing my math correctly that's 11.2 to 12.0, my fuel pump duty cycle is about 44 to 47% so it's almost maxed out with me running ID1050X injectors and a 21 volt BAP.

Any knowledgeable E85 guys I'd like to hear your setup and what your seeing for lambda and fuel pump duty cycle.

Raises hand!
I run a triple 465 pump Fore return so I don’t look at the duty cycle as much, other than knowing I was fine and it’s stable.
I’m more concerned about my ID1300s when I go full kill on next years ported 3R combo.
First good choice on tuning with lambda language, it’s just a better way to focus.
I shoot for 0.79-80 lambda on E85-89, knowing that I’m safe when I occasionally see a slightly leaner 0.82 range.
I’ve found the car runs better at the track richer, so the 0.78-80 range is the bogey and I’m happy if it’s richer like .78
For those not familiar, please google lambda air/fuel ratio tuning. In a nutshell, lambda allows you to communicate your air fuel ratio no matter the fuel you’re running, with 1.0 being the ideal for that fuel (example the 14.7:1 gas ratio we all hear about would be 1.0 lambda). Usually an engine will make max power around 0.80 lambda, but that depends on many factors.
And Steve, I have an extra set of ID1300s and the ‘93 Cobra build I’m doing would be more than happy with 1050x, so maybe we can work out a swap. Hit me up if interested.
-J

^+1 what biminiLX is saying about lambda.

Don't caught up in figuring air/fuel ratios numbers like 14.7:1 or 12:1 etc., lambda is the real number you focus on. Have had a couple conversations with tuners and all they look at and talk about is lambda, cause no matter the fuel or vehicle 1.0 is "ideal" and they typically shoot for 0.75-0.85. I've made the switch to thinking in terms of lambda and that's what my Aeroforce gauge is set to, its way easier read and understand now.

Fore Triple return system. The 2nd and 3rd pumps are on a Hobbs switch. I shoot for 0.76 at the track.

2011 gtcs said:

Hey guys, so let's talk E85, I'm currently running it and was just woundering what you guys are seeing for A/F ratios or Lambda, on my logs I've been looking at I've seen .80 to .85, if I'm doing my math correctly that's 11.2 to 12.0, my fuel pump duty cycle is about 44 to 47% so it's almost maxed out with me running ID1050X injectors and a 21 volt BAP.

Click to expand...

Lamba is your percentage of stoichiometric. You would need to use the correct stoich value for E85, which is 9.8, to determine your actual air/fuel ratio. It's much easier to use lamba, than know all of the respective conversions for different fuel types. Since most gasoline these days is 10% ethanol, most stoich values for pump gas use 14.08 for most tunes, instead of 14.64 for gasoline.

Catmonkey said:

Lamba is your percentage of stoichiometric. You would need to use the correct stoich value for E85, which is 9.8, to determine your actual air/fuel ratio. It's much easier to use lamba, than know all of the respective conversions for different fuel types. Since most gasoline these days is 10% ethanol, most stoich values for pump gas use 14.08 for most tunes, instead of 14.64 for gasoline.

Click to expand...

I agree, I was more trying to figure out what my A/Fs would be at on E85. I know on pump gas my A/Fs were at .79 to .81 lambda or 11.0 to 11.2, and on E85 I'm around .82 to .85, so I'm guessing 11.5 to 12.0, .78 lambda on E85 seems pretty rich, but I'm not a tuner so I could be completely wrong.

I've always looked at A/Fs so this is my first time trying to really understand lambda and with ethanol that's the only way to do it correctly.

Your a/f ratios would be 9.8 x .79 = 7.74:1 and 9.8 x .81 = 7.94. E85 uses 1/3 more fuel than gasoline, so it's going to use a whole lot more fuel mass in relation to air mass.