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A/F with E-85

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92tsifwd

15+ Year Contributor
572
0
Feb 1, 2004
Hastings, Nebraska
I am building a all motor setup & I was wondering what WOT a/f ratio to shoot for with a n/a 4g63 build running E-85? Also what timing should I shoot for? What timing?

On another car that is a turbo gt35r fully built setup what WOT a/f ratio should I shoot for with E-85? What Timing?

I was told part throttle needs no tuning. Is this true?
 
part throttle requires tuning with e85 just as with any fuel.

set up your wideband to read gas, and tune it for 12:1 for the boosted setup as if you were using gas. (obviously the afr isn't 12:1) but since widebands read lambda and than multiply it to give a afr for a given fuel you can just *pretend* your on gas, and tune for 12:1.

as for timing, start with about 3deg advance across the board in comparison to a tuned map for pump gas and go from there.

Judging by your questions, you have done zero research and just asking questions that could have easily been solved by searching.
 
part throttle requires tuning with e85 just as with any fuel.

set up your wideband to read gas, and tune it for 12:1 for the boosted setup as if you were using gas. (obviously the afr isn't 12:1) but since widebands read lambda and than multiply it to give a afr for a given fuel you can just *pretend* your on gas, and tune for 12:1.

as for timing, start with about 3deg advance across the board in comparison to a tuned map for pump gas and go from there.

Judging by your questions, you have done zero research and just asking questions that could have easily been solved by searching.

I have been searching for about an hour & have not found my questions ansered. I still need to know what a/f to shoot for with a n/a setup. It is curently at 13.0.1 on 91. What should I tune for with full e-85? I know you have to add 30% more fuel accross the board. Do you still need to tune further than that for part throttle?
 
If you have a logger you can tune part throttle in closed loop, otherwise you might need to tune in open loop if you can't log fuel trims. Every car will run different on the same platform and fuel so your tuning needs will be unique. You should be more than safe at 13.5 afr N/A and 12.0 Boost. Start with low timing and advance til you get a couple counts of knock then back the timing up a degree. (I like 0 knock) The WB will read the O2 content in the exhaust stream and that is what is important so forget about what you read on stoichiometric afr for e85 cause your wideband don't measure fuel.
 
What are you using to tune with??
I would highly recomend dsm link as you will need its adjustability and bigger injectors when using e85
As far a AFRs shoot for 12.0 WOT
your part throttle should read 14.6.
Your part throttle tune is all done with your lower HZ air flow siders
Your oxygen sensor trys to keep your part thotttle afrs at 14.7
 
What are you using to tune with??
I would highly recomend dsm link as you will need its adjustability and bigger injectors when using e85
As far a AFRs shoot for 12.0 WOT
your part throttle should read 14.6.
Your part throttle tune is all done with your lower HZ air flow siders
Your oxygen sensor trys to keep your part thotttle afrs at 14.7

I am using a NGK AFX wideband & a palm for data logging. I have tunerpro rt tuning softwhare. I can play with injector size or maf comp to compensate for closed loop. So dont worry about 02 volts then, Just go off the wideband?
 
Yea just go off the wbo2. I would say 13.0-13.5 afr should be good on e85. Your best bet is to talk with some N/A guys that have more experience tuning n/a AFR's.

12.0 AFR is where I tune my car on e85.
 
Yea just go off the wbo2. I would say 13.0-13.5 afr should be good on e85. Your best bet is to talk with some N/A guys that have more experience tuning n/a AFR's.

12.0 AFR is where I tune my car on e85.

Thanks for all the info guys. I will get her running hopefully this weekend & start by mixing a few gallons with 89 & work to get it running on full e85.
 
Just remember.. These various AFR's that are stated 12:1 13.5:1 14.6:1 ETC, are not the actual AFR, this is just if you have your wideband set up to give you a reading for gas. Remember, widebands read lambda than depending on what fuel you tell it your using just does a match conversion to convert it to AFR for a given fuel.

Goodluck.
 
I wouldn't half mix unless you plan on keeping it that way, filling up half a tank then filling the rest with gas?
Either go all E85 or all pump. It will simplify things.
The nice thing about E85 is its very easy and forgiving, just don't run it too lean. I've seen tests on it on boost that run it into the 13;1 area and still no knock or bad heat issues.
Run that sucker empty and fill it, make sure you change your filter after the first tank or two.

edit; the NA tune you'll need to search for, I'm sure its going to be richer AFR than what the gas AFR would be(reading the same lambda)
 
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