I finished the ignition upgrade last night. The latest performance project for the MINI was to improve the ignition system to match the improvements in airflow in and out of the engine. Because the smaller pulley produces more boost, the induction air is a bit hotter than stock. Since the air is hotter, the spark plug is one step cooler. Because the air/fuel mixture has more potential energy, the coil is upgraded to produce a stronger spark. To get that stronger spark to the cooler plug more efficiently, a plug-wire with lower resistance is used. This all doesn’t add up to more horesepower directly, but should reduce horsepower loss due to system inefficiencies, if that makes sense. The net result is a smoother running engine and actually better fuel economy.

The combination I used included MSD 8.5mm wires and a Screamin’ Demon Coilpack (like the MSD coilpack) and NGK Iridium Plugs.

I was actually surprised by the condition of the old plugs. My MINI now has over 60,000 miles in less than 3 years of motoring. These are the original plugs. They’re rated to 100,000 miles and would probably make it. (An even tan color is good.) I’m used to plugs that wouldn’t last 10,000 miles let alone 60. Interesting to note that this is only the second part (after the brake caliper) that I’ve found that says “BMW” on it.