rusefi.com

A smaller sibling of https://rusefi.com/forum/viewtopic.php?f=4&t=507

This is the connector used on original Mazda Miata of the first generation.

Some progress was made at https://github.com/rusefi/rusefi/tree/master/hardware/breakout_48_pin_174917 and then we got distracted

@Crazy Striker has made some progress we have gerbers now!

Sent to fab!

https://www.ebay.com/itm/333685945346
Any info about the max current the traces (or copper width/weight) for the bigger contacts of this PCB can handle - like injectors, power, power grounds, etc. Pins 1B, 2A, 2B, 2C, 2U, 2V, 2Y, 2Z. Also any info on the holes diameter on the breakout part for these contacts?
I am looking to buy this one to make an ECU header patch cable for a '94 Miata but I want to make sure it can carry the load/fit the wires.

mx5 wrote: ↑

Tue Jan 26, 2021 2:14 am

Any info about the max current the traces (or copper width/thickness)

"Sufficient"? 64 pin sibling sold many many times and it just works for miata.

AndreyB wrote: ↑

Tue Jan 26, 2021 2:18 am

"Sufficient"? 64 pin sibling sold many many times and it just works for miata.

The patch cable I am building is for a MS3Pro Ultimate - it has lots of I/O. The OEM Miata wiring harness has three power grounds (through the .070 pins, 16 AWG wire on each one) so it can handle it, but looking at traces at the breakout board picture (from the ebay link I posted above) got me worried a bit, thus my question here to get more info on how much current per trace for the pins with the .070 contacts.

I think I got the answer myself.
The github link at the top of the thread is dead and I found the proper one here:
https://github.com/rusefi/rusefi/tree/master/hardware/Breakout_48pin_174917-Connector
Opened the gerber file to get more info about the traces.
So ... the OEM Miata harness has the power grounds on pins 2A (injectors) and 2B (outputs).
In the gerber file each of these traces is only 0.25mm wide.
That is tiny and quite undersized. The total current of 4 injectors is around 5A which is way over specs of such trace (or even 0.5mm for both 2A and 2B combined if internally connected) that wide and then we add the extra current going through the the rest of the outputs.
Unless the board uses some custom super thick copper layers but nothing hints of a such thing.