Discussion and questions related to the course Practical Motorsport Wiring - Club Level
When running the harness through the firewall what connection do ya'll us?
It depends on the number of wires and the budget. Lots of choices from places like milspec wiring:
I've had great luck with this company.
For professional/bling go Deutsch AS and ASL.
For club/amateur I use Deutsch HDP20 series for quick disconnects/CPC and for semi permanent installs Deutsch DRB. Nice thing about sticking with Deutsch is pin commonality.