Project NSX: Part 21 – Foundry 3 K-Coil Swap

With forced induction on the horizon, we upgrade the spark energy for our C30A engine with the Foundry 3 K-Coil Swap Kit.

The Foundry 3 K-Coil Swap Kit is a complete Plug-N-Play solution to run one of the best and modern OEM Honda ignitions systems in the NSX (an aftermarket ECU, inline ignition dwell modifier, or a Prospeed ROM is required).

The swap kit includes instructions, all mounting brackets, adapters, connectors, and wiring to make K-coils work on the NSX’s C30/32 V6 engine.  Foundry 3 based their kit off of the NSX GT300 layout and design as those race cars used these coils instead of the original NSX coils.

The new Foundry3 kits feature wiring looms with Raychem DR-25 heat shrink and SLS 3D printed Nylon seal adapters made on industrial laser sintering printers to reduce thermal conduction to the coils to keep them cooler.

The Honda K-Series Coil (P/N: 30520-RRA-007) are extremely capable and are widely used in the aftermarket industry in many builds as they support 300whp per coil without ignition breakup!  4-cylinder K-series engines are making over 1,000whp and 9,000rpm+ on these factory coils.  With 2 extra cylinders on the NSX, these coils have enough spark energy to support over 1,500whp!

The NSX’s factory coils are a very old “dumb” design that requires an external igniter compared to modern “smart” coils that have built in igniters and overheat protection.  These coils max out around 750whp under ideal conditions (i.e. New coils) and even that is pushing it.

For the 1991-1994 NSX; P/N: 30520-PR7-A03 (front) 30521-PR7-A03 (Rear) are getting harder to come by, and are more expensive than the fare more capable and modern K-coils.