What is the safe AFR for E85? I was running at 11.3:1 on gasoline @ 5psi and 20* right now I have it set at 7.7:1 on E85. Is there a recommended range?

 

Y ou can run E85 at the same 11.3AFR according to your WB. Go to the forum Innovative has for a better explanation. But Lambda doesn't change with fuel but Stoich does, so just leave your WB alone and keep tuning at 11.3 with E85

 

I am just looking for the power enrichment AFR for HPT. I have figured out that when the wideband says 14.7 I am actually running my stoich AFR of 9.7.

 

Assuming you changed the injector size to accommodate E85 you shouldn't need to change your PE factors much if at all. Just use your WB to tune your PE at WOT to your 11.3AFR.

 

Those numbers sound about right if you're tuning off the correct AFR table. This is how I do it also. You can achieve the same thing with the IFR table, but I just command the base AFR table to what I want from the fuel (although I can test it first). My truck and Tahoe run in the 9's at cruise and low 8's at wide open for commanded AFR. The wideband reading is more what you're concerned about, but yes your commanded numbers sound about right.

 

I just increased all cells in my main ve and boost tables by 20% and went out and logged. I am tuning same AFR as I would with gasoline, 11.2ish at WOT.

 

Your AFR reading at the wideband in the exhaust is going to be the same as running gas. When you change the AFR spray you are commanding the correct amount of fuel spray to the amount of air coming in without tricking the system via the V.E. table, I.F.R. table, etc.

 

I did nothing with my VE table, but changed my stioch AFR to 9.7. I filled it up and it showed 12.2 AFR at idle. Based on my conversion chart that is 7.7:1. So, do i tune the VE table to show a 14.7 AFR on my wideband and forget the commanded AFR displayed in HPT?

BTW this is a 2bar SD tune.

 

You did it the right way. Before you go adjusting too much here are a couple of things. If you haven't ran a couple of tank fulls through of E85, you want to wait a bit until you make sure that you only have E85 in the tank and not a bit of gas only left in there. Changing that 15/85 ratio of gas/ethanol can screw that up quickly. The next thing to do is to check your stations mix. Get a sample of your mix and stop into a GM dealer and let them test your E85 to make sure your station actually has a mix of 15/85. Many stations have an incorrect mix because their quality control on E85 isn't very good. All GM dealers have a test kit for this because dumb ***'s running E85 in non flex fuel vehicles is so common. This is how they find that. If non of your local dealers will do that the dealer in Grand Haven called Gage Chevrolet will. Find out how much your concentration is of Ethanol to Gas is and that will tell you what exact number to use for your base ratio. Having this number correct will make fueling more consistant and really help you dial in your V.E. and P.E. numbers. If you don't have the chart for that find out what your % number is and I can give you the AFR to put in.

 

Cool thanks for the info. Berger should be able to do the fuel test.

I went into my wideband manual and it does not have the capability of displaying proper AFR with the ethanol equivilancy ratio, so, I am just going to put the stoich AFR back to 14.7 and add 20% to the VE table to compensate. I loaded the tune and started it up, the AFR at warm idle showed 16.4:1. With the histogram i was able to tune it in.