The #3 injector was replaced with the next richer size and there is a slight improvement
This time I wrote down the values by hand because you get 1F resolution that way, whereas logging resolution is 5F. But it still is difficult to do well because the EGTs fluctuate by 5-10F.
I think it’s possible to change the ticker size to 1c, at least on the EDM700 it is.
Yes, and I have that, but AFAICT it works only for the display, not for the logging feature.
So, one could get finer data by sitting there and writing the numbers down from the display 
I used to think that JPI changed their software at some point, to increase the amount of data which could be stored, and this is how they did it, but they never replied when I asked them on multiple occassions. I changed the unit from a 2.5" one to a 3.125" one; thread here and I think it happened then; the software could not have got changed at any other point. However a check of old data from 2002 shows that the logged data is always at least 5F between consecutive samples.
The POH figures on my TIO540s are ROP at 75% and LOP at 65%. The POH was written long before GAMI was invented (the aircraft is 1973, so the POH must’ve been written in the late 60s, I guess) but the figures are absolutely bang on and work perfectly in my non-GAMI engines.
Peter,
I think it’s possible to change the ticker size to 1c, at least on the EDM700 it is.
One thing to remember about GAMIs: if the engine S/N changes, you need to get a fresh GAMI STC, for $300. They will also send you a corrected injector(s) as required.
I am getting a new #3 injector.
What is really interesting is how close the injectors from the old engine are on the new engine. The last set on the old engine is here and the 0.2USG change is really minimal.
So clearly the main reason for GAMIs is to compensate for the different routes for the incoming air, to different cylinders.
A GAMI spread of 0,2 GPH is really good!
Here is the GAMI test from my new engine, after 8 hours. The old GAMI injectors were installed in the same cylinders as before.
It is really good
I will send it to GAMI but I doubt they will suggest replacing #3.
The above was at low level cruise: 23" 2400rpm 11.5GPH, 4300ft +6C. 140kt IAS.
The reason for the big steps in the values is because the crappy JPI/EDM software stores values only if they change by 5F or some such.
Howard wrote:
Could someone explain to me how I go from having a datafile that I have output from my EDM700 (which I have on my Mac) to having a valid order for Gami injectors. I can’t find such an obvious question answered on the Gami website. I was expecting their website to have an email address to which I could send my EDM data file and a webpage on their website which invited me to do just exactly that in order to create business for them.Thanks
Howard
I have ordered them (TCM TSIO520) and indeed this was unclear until I have actually placed the order and I was told that my carefully obtained pre-installation GAMI test was of NO USE, because they normally send you an “initial set” of injectors, which is the same for every engine of your type; then you do the GAMI test and if your GAMI spread is too large, they swap one or more injectors for different ones, or tell you to swap specific injectors in the engine. Wihin 12 months after the initial order they do it for free. I have installed them and I must say that they are very useful and the GAMI people very nice. They come handy even if you do not want to fly LOP, because they allow you to get better fuel efficiency even at ROP operations (assuming that you do care and monitor the EGT/TIT for that purpose). I can confirm that the initial set reduced the GAMI spread significantly (from over 2gph to approx. 1.1gph) but we will need at least one more iteration before we are within the desired 0.5 gph band.
I got this reply from GAMI:
I think you have to be doing a lot of hours to recoup the investment in Gami injectors but perhaps for some it’s more a matter of perfectionism.
Not at all. Some engines cannot run at peak EGT (the best MPG point) without excessive vibration. Here is some data from today – look at the fuel flow and the speed:
(Caveat – this is FL110, +6C, and you do get different curves for different altitudes)
The average UK PPL flies at the bottom one – mixture lever fully forward
GAMIs will pay for themselves far quicker, in most cases.
If GAMI take your EDM data directly, that’s great. They never used to.
