Civic-Integra MSD External Coil Conversion

This write-up will work with virtually all Honda Civics and Acura Integras (Preludes and Accords already have an external coil).

Theory

Obviously, bigger is usually better, but why is this upgrade important? On a stock engine, this upgrade will probably not do much. In a boosted, sprayed, or high compression application, the extra voltage along with the capacity of the larger coil will yield more consistent power output.

The larger coil will allow for better recovery after a discharge. After the coil discharges, it has to build it’s electric field back up for the next spark. High rpm applications will definitely need a bigger coil to ensure that the spark is steady and consistent. Ideally, having separate coils for each plug is the most advantageous, but for the sake of a good, low cost upgrade, the external coil conversion will work very well.

Tools Necessary:

socket set
screw drivers
wire cutters
wire crimper
soldering iron

The first part of the process is to remove the distributor for easier access to the components. However, you do not need to remove it. If you can do the work while the distributor is on the engine, you can avoid having to set the timing once it’s finished.

MSD-cap-coil-1 — If you plan to remove the distributor, take the time to remove the coil first. Start by removing the cap, the rotor and the cover under the rotor. Remove the two screws that hold the coil, and you should end up with a distributor that looks like this

MSD-cap-coil-2 — Here is a shot with the coil back in the distributor. Please note the wires you have to remove from the coil

MSD-cap-coil-3 — Cut the original connectors to the coil and strip back the insulation.

MSD-cap-coil-4 — The polarity of the wiring is very important. The Black/Yellow wire is the positive wire. The Yellow/Green wire is negative. I chose to solder the wiring for a solid connection.

You can use tape or shrink tubing to cover the joint. I fished the wire through the rubber grommet on the bottom of the distributor. I used a pair of small side cutters to carefully cut a section between wires, and pushed the new wiring through.

Once the wires are solder (or crimped) and tucked, install the cover.

If you’ve removed the distributor, install it on the engine. Attach the new wiring to the new coil. I used crimp ring terminals to attach the wires.

Install the coil where it is most convenient for you and connect the plug wire to the cap and coil.

Make sure to set the timing on the distributor (if you removed it) and enjoy the new spark!