Ignition System Overhaul Continues Body Swap Project
There’s always something new to learn with 91ĚŇÉ« Tech’s “Tech Tips” – part of Motor Trend’s “Hot Rod Garage” web series.  In Episode 50, Tony examines how modern ignition systems can impact your car’s performance.
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Host: Welcome back to another 91ĚŇÉ« Tech Tip. Today, we're going to talk about the modern ignition system that you would use with an after-market EMS or engine management system. Yeah, there are those old-school distributors with points and magneto systems, but those don't really apply here, so we're going to skip talking about them.
An ignition system's function is to deliver a high-powered spark to each cylinder at a specific time in a combustion cycle depending on driving conditions. Okay, let's dig into these modern ignition systems and see what they have to offer.
Which modern ignition system is right for you?
The first thing is we're going to talk about is an electronic distributor and single ignition coil. The modern electronic distributor has either a Hall effect or an optical sensor, and that's going to tell the computer how fast the engine is spinning and where it is in the cycle. The computer will take that information and deliver a spark at the proper time from the coil, through the distributor, to each cylinder. This is a simple and usually cost-effective system, but it has a lot of moving parts, and it does not allow for as much timing control as other systems.
The second system we're going to talk about is a distributorless waste spark setup. This is a big step forward in tuning. In this setup, there will be a combination of sensors on the camshaft and/or crankshaft that will tell the computer how fast the engine is spinning and where it is in the combustion cycle. The computer will fire a single coil per two cylinders and match them so that they will fire a wasted spark on the cylinder that is in the exhaust stroke, and the main spark on the cylinder that is in the combustion stroke.
The final system we're going to talk about is a distributorless coil-on-plug system. This is the most advanced system on the market today. Like other distributorless systems, the engine computer, or EMS, will use a combination of camshaft and crankshaft sensors to input the engine RPM's speed and the position of the engine in its cycle. But instead of having to fire one coil per two cylinders, the COP, or coil-on-plug, system fires one coil per cylinder. These are usually mounted into the valve cover. The advantages here are a very tidy installation and the EMS has total control over the timing curve.
Our 4.6 Mod motor is a coil-on-plug setup. Now, that will allow our Holley EMS total and complete control over the timing curve allowing it to attract maximum power from our Crown Hick truck.
All right, so now that we're clear on modern ignition systems, let's get back to the shop.
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