12 GA - 22 GA M22759/32 cables

Hello,

I've been lurking for some time to try and read as much information as possible. I am starting a loom construction and trying to plan everything out it is specifically for a JZA80 MK4 supra. It is going to be a M150 MOTEC ECU running 12 injectors and GTR coil packs. From what I'm gathering to power the GTR coil packs with the amperage draw I decided to go with the M22759/32 12 GA and start splitting of to 20 GA GA wires applying it components that need 12 volts and running 22 GA for inputs / outputs. Since I'm still very new and being very ambitious to build this loom I cannot decide which Autosport I would need to best fit this application. it is an expensive investment and I want to make sure that I get the correct one once. I'm using a small bulkhead to pass power cables and using a bigger Autosport to pass all the inputs / outputs. I'm having a hard time deciding since I'm still in the early stages of planning this harness out. I'm driving myself crazy seeking for some opinions on what I should do.

Below I built a GTR sub harness with 20 GA power / ground / input wires and still feeling like got a long way to perfect a loom

Thank you

-Eric

G'day Eric.

First up, that GTR sub harness looks really top notch, nice work!

12AWG sounds really large for the current feed to coils. Remember that the current passing through the coils build up from zero to some maximum value over the dwell period of the coil, so you can think of this as the coil drawing half of this maximum current level over the entire dwell period...

What I'm getting at is that sizing the wires to the coils isn't done by looking at just the max current the coils will draw, there is a little more math involved.

As you've probably found, a suitable autosport connector with pins that will accept 12AWG wires is going to be tricky to find. I would more commonly run 16AWG in a situation like this, with a right revving engine and powerful inductive coils. This should open up your connector selection. The other option is to run multiple smaller gauge power wires that you will be able to find a connector to accept more easily. This usually makes the concentric layup plan easier as well, if you're going that route.

Cheers.

Zac.