Hi all,

Looking to adjust my tune, currently tuned on 91 E0 and its running mint, but want to go to 93 E10 so I can add a little timing.

Am currently incorporating AFR target in my PW calculation, will simply adjusting my "Stoichiometric AFR" from 14.7 to 14.1-14.2 get my fueling correct? This intuitively makes sense however the way the fueling equation is written it seems as if this will decrease PW, which makes no sense. When going from no ethanol to some ethanol I would want to increase PW and get more fuel into the cylinder, no?

PW = ReqFuel * VE(rpm,map) * MAP * stoich / targetAFR(rpm,map) * GammaE

Running a PSB-1 wideband, which to my knowledge is converting a Lambda value to AFR, so regardless of my fuel type, the "stoich" reported to mega squirt will be 14.7.

Basic intuition says that I want to multiply all my PW's that I am running currently by 14.7/14.2 ~=1.03 (or so) in order to get the correct fueling for the E10 gas, does this make sense? / what would be the best way to go about getting my tune "close" without touching my VE table.

Any help would be appreciated!

 

I would do nothing, more variance in the pumps you'll be visiting than the small bit of ethanol.

And that was the point. They figured that was the most ethanol you could add to things designed for gasoline without them ******* up, and for once I agree.

 

I want to agree, fuel companies have probably spent billions in research and data but a 3-4% fueling error seems like a lot. That would pull an "afr target" of 11.8 to 12.1 (11.8*1.03), which is easily enough for things to get a dicey in boost.

 

Not if you have EGO correction on and working properly