4 Easy DIY Upgrades of Your Car’s Ignition System

An internal combustion engine needs three main things to operate: fuel, air, and ignition. Arguably, ignition is the most critical because it needs to deliver high-voltage power to each spark plug thousands of times a minute. That power is precisely timed to ignite the air/fuel mixture in the cylinder and thus deliver optimum power.

There are three main components of the ignition system in a classic vehicle:

• A coil creates a high-voltage current that is sent to the spark plugs.
• Breaker points switch the coil on and off at precise intervals.
• A distributor routes the high-voltage to the correct cylinder in time for the coil to discharge its voltage to the spark plug.

With aftermarket ignition systems, you can take advantage of technological improvements and increase engine performance. Here are four easy-to-perform DIY upgrades for your ignition system that can result in better starting, throttle response, and fuel economy.

Get Rid of the Points

Upgrading to a breakerless ignition system is one of the quickest and easiest DIY projects. The old “points” system requires constant maintenance and frequent parts replacement, and is prone to inconsistent performance.

A solid-state microprocessor-based controller replaces the breaker points in your vehicle’s distributor. This system utilizes trigger magnets that spin with the distributor rotor, signaling the control module when to deliver voltage to the ignition coil.

There are no moving parts, so consistent timing is assured even at high rpm. This type of upgrade is ideal for a collector car restoration because the upgrade fits entirely under the existing distributor cap with only two wires to connect. The period-correct coil can still be used.

Upgrade and Combine the Distributor and Coil

If you modified your engine with improved compression and intake, and your goal is better performance, upgrading to a modern high energy ignition (HEI) system is the next level of DIY that is still easy to accomplish.

HEI systems combine the distributor with a high-voltage coil and have an integrated breakerless switching module built into the distributor. It’s a popular upgrade for older American vehicles.

General Motors led this innovation, but other companies have adopted the concept.

A typical HEI system can produce up to 40,000 volts versus 18,000 volts for a breaker point system. The higher spark voltages are critical for the reliable operation of high-compression engines. An electronic ignition amplifier is a popular add-on for an HEI distributor, which increases the spark energy even more than an HEI system. It also increases the duration of the spark for complete combustion.

If you opt to avoid an HEI upgrade, consider at least upgrading the coil. The new electronic distributor system can handle more spark, and the ignition system’s upgraded coil can dramatically increase the voltage supplied to the plugs.

Change Spark Plug Wires

After a few years of driving, it is time to change those spark plugs. If you followed our advice and swapped to a higher voltage spark, you should install spark plug wires designed for that voltage.

Conventional spark plus wires might have a 7 mm core, but the minimum with a high voltage system will be at least an 8 mm core. Some vendors offer to size up to 10 mm.

Install an Ignition Box

You probably have seen an ignition system box under the hood of cars at the local drag strip. These devices are great for street applications as well.

At below 3,000 rpm, these devices increase the sparks to the plug from one to three for each compression cycle. More sparks produce more ignited fuel for greater power. These devices also allow for a rev limiter to prevent an overly enthusiastic driver from exceeding the red line of the car’s engine.

Ignition boxes come in two types: analog and digital. The digital versions offer more precise control of the ignition system’s sequence and are more accurate.