I used to have an .xls that someone on here gave me a while back that you enter you desired AFR, Logged AFR, and AFR value set in ECUFlash. It would then result with a new value to enter into the ECU.

I loved this tool, but my PC died and I lost it.... Anyone have a copy I can snag from you?

Thx

 

I used the following .xls formula:

The formula to adjusting the fuel map is very simple. Let us look at the 5500 rpm row and load cell 220 in the log chart above. The Actual AFR (AAFR) is 11.13:1. The fuel map AFR (MAFR) shows a 9.7 number in the 5500 rpm and 220 load cell. Let us assume that we want a desired AFR (DAFR) of 11.4:1 in that load cell. What should the new map AFR (NMAFR) be?

NMAFR=DAFR X MAFR / AAFR

NMAFR=11.4 X 9.7 / 11.13 = 9.9353

So the number that you should enter in the fuel map in the 220 load cell @ 5500 rpm should be 9.9.

To make this easy on yourself, simply create a template in excel with the above formula and use it over and over again. This way you will not have to do any manual calculation. Just plug in the numbers and excel will take care of it. That is what I did and it works like a charm. This method takes the guessing out of AFR tuning and allows you create a very flat and consistent AFR. Below is a 4th gear log with the AFR indicated @ spool up, peak boost and 7000 rpm. It is nice and flat from 3800 rpm to redline. The data is not smoothed. Logworks and Evoscan do not smooth the data. Logworks allows you to smooth the data afterwards. I like the data raw.

 

I just usually add in a couple of columns in my log file. One is for my Desired AFR, the other for the calculation. Then I input what I want my AFR to be at 3000 rpm in the Desired column, figure out what I want it to be at redline, and have excel fill in the blanks in between so it gives a nice transition. Then in the calculation column, create a formula of "Desired AFR" - "Actual AFR" = map cell change (ie: -.2, .5, etc). Then I just adjust the cells per the change column, and highlight them as I go, and save the end product as a record of what I have changed.