I've been trying to do some tuning and I have a question regarding AFR and LC-1 readings. The LC-1 has been reading good for my gas tuned and has been very accurate in terms of my AFR readings. My question is what target AFR am I looking for, for E85 if the LC-1 is calibrated to reading gas?

The reason I wonder is because as I have read on various thread, E85 seems like anywhere from mid 11's to low 12's but when I tune for that AFR via the LC-1, I am getting knock sum readings in various areas when running in the 11's. I played with timing after getting the AFR dialed in, adding and taking timing out but it still spits out knock sums. However, when I use the same timing map and lean out the fuel map to the 12's the knock sum is virtually zero. I can maybe at most 3 counts under normal driving conditions while 0 at wot. My WB reading is relatively lean, low to mid 12's.

So my questions, is my car actually running that lean even tho my WB is scaled to read gas while I'm running ethanol? I'm just confused because when the AFR is in the 11's I get a lot my activity on the knock sum while its nice and quiet when its on a lean fuel map? it was even quiet when I was messing around with the fuel and accidentally went up into the 13's, it still didn't knock on me at all?

 

You're good. Gas calibrated AFR of 12.2-12.5:1 is considered the sweet spot for E85. Even 13:1 is prolly OK if you are making good power with no knock.

Remember, E85 is 105 octane and VERY resistant to knock.

 

thanks! It feel really strong and I'm loving this setup with the cold weather too.