Coil Pack Testing

[immortality]

What are you using as your test voltage?

Have you tested other voltages to see what happens to the spark if say the system voltage is bellow optimum (14.4 volts)?

[Gareth]

or when a higher voltage is used like is often done with high end drag car ignitions

[Dylan]

There's a post a few pages back probably by now I asked about stepping up the primary to 16V like some drag car's as suggested, no gains were had from The1's testing.

[immortality]

Lower than ideal voltage is probably more relevant as it's a more common situation than over-voltage.

[The1]

Yeh under around 10volts most loose there spark and it goes very weak, above that it works, this was testing at the max gap, i did all the testing at 14volts as that is a usual figure for most cars and it was where the coil drew the most current, the max ive seen is 3 amps from a coil most are less than that, at 3ms dwell the current draw is pretty steady, unlike higher dwell which is dips and peaks alot.

[pman92]

I imagine lower primary voltage (below 14v) would be problematic with less dwell, but still be reasonable if you increased dwell?
And higher voltage (eg 16v) would allow good spark with less dwell than 14v.
I guess the higher the primary voltage the faster the coil saturates.

Just out of curiosity what are you using to drive the coils when you test them?

[The1]

N mosfet circuit, just diodes and resistors with a signal gen,

[The1]

Updated the results on first page, looks like my delphi coil was not genuine, i got another one which has Delphi stamp on the side with the GM part number, the other one was identical but no stamp on the side which performed the same as stock, but this genuine part performs the same as the lowest MSD coil, i need to get a couple more i think and some new MSD's to test, but it's all starting to cost lol i think ive done what i aimed to do and some more, also tested LSX coils, im not sure which model specific it is but its used OEM GM so ive put the part number in. Ive updated the graph to include used/new

[The1]

Here's the genuine Delphi coil with the 45mm result, grey bottom like old OEM ones and gold posts

[Dylan]

I think there's only 2 LS style coils from GM. LS1 and anything later LS2 3 7 98 etc all ran the same from what I've come across.