For those who have not seen my other thread about uneven airflow, I figured I repost a rundown of what has happened to get my GAMI to zero.
I have a new Titan IOX370 running dual EFII ignition and injection with vertical induction. With the stock setup, I had a GAMI spread of 1.3! In trying to determine how to reduce the GAMI spread, I realized (with the help of my neighbor Rusty Crawford) the root cause of the high spread was uneven airflow between the 1/3 cylinders compared to the 2/4 cylinders. This was determined because when ROP, 1/3 had the hottest CHT's, but when LOP they were the coolest (and I verified it was not due to injector imbalance).
So, after some research, it was recommended to me to swap my ECI sump out with a Superior sump. Apparently the Superior sump is known to have better airflow. So, I sucked it up and swapped the sump out, and to my surprise it made absolutely no difference in my temperatures. So now what?
Luckily, Rusty told me that for the past few years he had been working with Ross at SDS on technology where each individual injector could be tuned. This would be a precise way to handle my airflow problem and get me theoretically to a GAMI of zero. Well, the guys at SDS finished the new circuit board and sent it to Rusty for installation in his -7, but Rusty's -7 was down for painting. So, Rusty asked if I'd like to be the first to try out the new technology! How could I refuse?!?!
So, with his help, the modification to my existing EFII setup only took a few hours and was relatively simple.
As the pics below show, after 45 seconds of tuning, I went from a GAMI spread of 1.3 to a GAMI spread of 0. Engine runs smooth all the way to about 200 deg LOP where as before I could only get to about 80 deg LOP since before when 80 LOP, cylinders 1/3 were at about 200 deg LOP.
Another benefit is now I have a clear picture of which cylinders I need to focus on for better cooling. Before I would have thought it was 1/3, but actually I need to work on 2/4 first.
Plus, now I am getting more average power with less wasted fuel since all of the cylinders are making optimum power.
Amazing work by the SDS team and Rusty Crawford. This has been many years in the making! I feel so lucky to have gotten to try this out for them!!!
Picture 1 - Leaning to LOP before the tuning - GAMI approx 1.3, notice large EGT spread, also notice 1/3 had highest CHT's and EGTs' when ROP, but coldest when LOP
Picture 2 - Leaning to LOP after the tuning - GAMI 0, notice how 2/4 always have hottest CHT's now.
Picture 3 - ROP climb before tuning - Large EGT spread
Picture 4 - ROP climb after tuning