In this guide I’ll be upgrading a Honda B20B engine (from a JDM CRV) in a 1991 CRX Si to coil-on-plug. This method will be largely the same if you have a D, H or F series Honda engines. In the 90s cars used a mechanical distributor to send high voltage current to the spark plugs in the engine. It was nice and it worked but it can be less precise and is harder to tune, which is important in a turbocharged setup.