Spring has come a bit early to the Midwest and I was able to finish my Megasquirt EI installation that I started in December. These are self-built and relatively inexpensive. No learning curve, as I have built one in the past for my air cooled Porsche (fuel injection and ignition in that case). I ended up using an old slick mag for the pickup. I left the shaft in place and fabricated a 6-1 wheel using magnets and a hall effect sensor mounted on a custom bracket where the points used to be.
I programmed two timing curves, one for ROP operations and one for LOP operations and installed a switch next to the mixture for switching between the two.
We had relatvely low ceilings and a fair amount of chop today, so didn't get to do much testing, but had a few observations. I can now easily get my idle RPM down into the 500's. This made a BIG difference in my landings (FP prop). When I chop the throttle now, I can really slow down in the round out and flare. Examining the logs, it looks like I picked up almost 100 FPM in my initial climb. I didn't get to do any really speed tests yet, however, at 2500' and LOP, when I hit the switch to go from 30 - 35 degrees advance, I picked up almost 40 RPM, which should be about 5 MPH on my setup and on top of what I might have already been getting, if anything, by being at 30*
I can't wait to get to 8000 feet and do some speed runs to see how much improvement I got. I will also do some comparisons against a 25* advance.
The most interesting benefit was the tightening up of my EGT peaks. With two mags, the spread was pretty ugly in most phases of flight (I have a carb). The EI made a significant difference that I wasn't expecting. My next project is to install a Bendix FI, which will let me improve upon that more.
I'll report more results as I do more testing.
Thanks to Michael for posting your test details and results. It was a big help in setting up my initial tables
Larry
I programmed two timing curves, one for ROP operations and one for LOP operations and installed a switch next to the mixture for switching between the two.
We had relatvely low ceilings and a fair amount of chop today, so didn't get to do much testing, but had a few observations. I can now easily get my idle RPM down into the 500's. This made a BIG difference in my landings (FP prop). When I chop the throttle now, I can really slow down in the round out and flare. Examining the logs, it looks like I picked up almost 100 FPM in my initial climb. I didn't get to do any really speed tests yet, however, at 2500' and LOP, when I hit the switch to go from 30 - 35 degrees advance, I picked up almost 40 RPM, which should be about 5 MPH on my setup and on top of what I might have already been getting, if anything, by being at 30*
I can't wait to get to 8000 feet and do some speed runs to see how much improvement I got. I will also do some comparisons against a 25* advance.
The most interesting benefit was the tightening up of my EGT peaks. With two mags, the spread was pretty ugly in most phases of flight (I have a carb). The EI made a significant difference that I wasn't expecting. My next project is to install a Bendix FI, which will let me improve upon that more.
I'll report more results as I do more testing.
Thanks to Michael for posting your test details and results. It was a big help in setting up my initial tables
Larry
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