e85 wideband

[byebyev8]

I have a older plx m300 wideband that I still haven't hooked up yet. I'm running e85 and want to hook the wideband up. But i know the lowest it'll read in a pump gas afr is 10.1 af which is 14.1 for e85 which is to lean. So how will i ever know what my afr at wot is on e85.

 

[jrohner]

If you leave the gasoline settings for the wideband (which most people do), you tune it like gas AFRs. The wideband doesn't KNOW the true AFR, it knows lambda/stoich, that is converted to an AFR number by using the stoich value of the fuel (14.7:1 for gas, E85 is 9.765:1). 10:1 gas AFR on E85 is too rich for it to even run decent (6.6:1 E85 AFR). You'll just shoot for say 12:1 AFR @ WOT, or whatever you like to tune for; cruising will still show the normal 14.7:1.

 

[byebyev8]

So its not like tuning a chip were you set the afr 8.1 for e85 in order to get a 12.1 afr.

Ok i understand now. I thought the wideband would read at the true e85 afr which would always be to rich to show up.