Tuning for E10

We have lost all ethonol free gas here. I have a couple of tunes I need to "fine" tune and I'm wanting to set them up for e10 only. I asked on the local board and everyone says they still use the same figures as they would for straight gas. I'm still learning this software, but I set up a histogram that has AFR error plotted against a VE table. In the tables, I have the AFR error listed as the NGK wideband sensor/14.12 to show my desired E10 fuel. Is this correct or am I losing my mind from all the reading I been doing??? Now somehow or another I read something else about the wideband reading on a scale for straight gas.....man I''m all confused.

Most pumps say "may contain up to 10% ethanol" but that doesn't tell us the actual amount. Try finding an ethanol test kit to measure the gas you're filling up with yourself. Most of the pumps around here in Minnesota are 6-7% E. Then you can go from there.

After you know the actual amount, it's as easy as plugging in your stoich value into the HPT box under the fueling tab and re-checking your AFR error, which should be re-adjusted for the new fuel but may be a few % off.

I'm assuming you mean under the scanner under fuel+spark then AFR control? Do I still need the modified formula in my error VE as I described above?

Post your logs, let's look at them in more detail before we go changing things ;)

The E10 here in my area (Northern California) tests at 7% and has for the last year. Ive never seen it over 8%. I run E85 and test it regularly as well and its always at 88-90%, Ive never seen it under 88% around here. The max is 92% and thats what they like to sell as its the most profit.

No logs, both cars I need to tune are not currently running...

have you changing your stoich afr

i would get them running first and then work from their

Ok, I set my NGK to read 14.2 as stoich via a good formula I found on another post, and am gonna set the stoich point in the computer tune to 14.2. So I should be shooting for 14.2 at all areas not in PE and 12.5 for PE?

Sounds good. :cheers: