Okay, let me start by saying I thoroughly appreciate all the research, hard work, endless hours of testing done by all of you and the hundreds if not thousands of comments on your results. I have an 85 GSL and am in the process of the fabled ignition upgrade. I noticed in my shop that I had many different coils, plugs, rotor housings etc....like most of our shops do . After reading countless threads I thought I'd try and contribute what I could. Being an electronics technician, nothing has more value than actually seeing and watching with your own eyes certain tests in action. How better to convince yourself what will work best than to fire OEM coils with OEM wires in OEM housings with OEM plugs.
Here is the setup: Since the popular igniter is the GM HEI, I started with an HEI distributor and removed the cap and coil. I mounted it horizontally above my bench and used a masterflex DC pump to rotate it (excellent because the speed is extremely variable) I then mounted a blown 13B rotor housing to my bench and used a combination of the Gen 1 and Gen 2 coils and plugs testing each coil with each plug . Same power source, same speed on the distributor reluctor, same wires to power the coil and ground the system. Note: the igniters were disconnected from the Gen 2 coils for consistency and because they require the ECM to fire properly. The only things I changed were the coils themselves and named each video respectively. I also wrote on a notebook the setup for each test to show in the video. This test opened my eyes to the differences between plugs and coils. I hope it has some value here.

Here is the bench in action before setting up the close up camera, notice the blurry advancer on the distributor showing its spinning, and looking close you can see my phone caught a spark.

These two shots show the bench after setting up the camera for close ups, both images and videos.


Each of these videos has been labeled with simple shorthand (mechanic's shorthand not the real illegible henscratch of yesteryear)
Gen 1 coil Gen 2 Leading coil Gen 1 Spark Plug at 3000 RPM will read G1G2LG1P3000, and change accordingly with each setup.
The best thing a fellow technician taught me years ago was that: No matter how good or bad you are, or think you are, a second set of eyes always works in everyone's favor.
That being said, I encourage everyone's questions, criticism, or any other ideas or variations I can test since my bench is completely set up and ready for more. I will add that I also tried out my factory coils for my 1981 yamaha and the result was very sad...
My eyes show the Gen 1 Coil matched with the Gen 1 Plug gives the fattest hottest spark of all the combinations, what do you all think?

Matt

 

Nice, I'd like to see the 2G coil and rx8 plugs and the TFI coil and rx8 plugs using the HEI.

The value of the DFIS ignition setups is you get wasted spark on the leading which gives you effectively
a longer spark on the combustion.

Also I'm not sure how the visibility of the spark relates to the actual heat generated by the spark. A
yellow spark is very visible but a really hot spark may be blue, white or almost invisible. A way to
measure or visualize the heat might be the most accurate.

All in all, its a great way to start comparing things.

 

This is exactly the kind of feedback I'm looking for and appreciate. My experience with electricity and circuits is vast and many years in the making, however when it involves high voltage and the fundamentals of reading arc strength visually, I have a lot to learn. Thank you.

I will most certainly grab some RX-8 plugs and run some tests.