Rob Kinnan
Brand Manager, Mustang Monthly
May 1, 1999

Step By Step

View Photo Gallery
With MSD’s adapter harness for the 5.0’s TFI ignition, installation is brutally simple. It just plugs in.
Here’s a close-up shot of the microcontroller. The MSD is programmed for operation on 8-cylinder engines so we won’t need to adjust the Cylinder Select Rotary Switch. The retard function works only when your 5.0 is equipped with a nitrous system. If you have a nitrous system, the MSD wiring diagram shows you how to wire it in with the nitrous system so you can retard the timing when the nitrous is engaged. Our car doesn’t have a nitrous system on it (yet), so we will move on. Next up is the rev limiter. There are two rev limiter functions—a 2-step and a max rev limiter. The 2-step function is for use with a trans brake to hold the engine at a certain rpm, and the max rev limit is the over-rev rpm limit—especially handy if you’re prone to missing shifts.
Yes, we do know this is a black-and-white article, however, if this were a color article you would be looking at the pink and blue wires. The pink wire is for hook-up to a nitrous system and the blue wire is for a trans brake. Our car has neither of these at this time. Don’t just cut these wires off, though. You never know when you’re going to step up to the plate for extra power, so save these for later.
Since our battery’s resting place is in the trunk, we chose the driver’s side inner fenderwell for a mounting place for the microcontroller. It can also be mounted on the backside of the front bumper reinforcement. The key here is to mount the box in an area that will see plenty of air flow. Heat is the biggest enemy of these microcontrollers.
When you mount the microcontroller, make sure the adjustable buttons are facing up. This will make it easier to make any adjustments later and will make it easier to tune the car at the track as well.
The next step is to remove the stock coil. Start by unplugging it. The removal and reinstallation of the MSD coil is probably the easiest part of this installation.
Next, remove the four screws holding the factory coil in, and take it out. No longer do we have to make a custom bracket for an aftermarket coil. In the early days of the 5.0 Mustang, performance ignition coils were still in their cylindrical shape, necessitating either a custom bracket or some type of rigged-up way of mounting it. These days, aftermarket coils come in the same shape as factory coils.
Here’s a comparison of the factory coil and the MSD Blaster TFI unit. The exterior design of the MSD coil is exactly the same as the factory stocker. This makes it a piece of cake to install the MSD Blaster unit in place.
Now we have the MSD Blaster unit in place. MSD also makes a harness to go between the factory wiring harness and the new coil, making this part of the installation a breeze. Just plug in the appropriate wires and you’re done.
Here’s the completed installation. All we have to do is plug in the coil wire from the distributor and head for the track. It doesn’t take a whole lot of time or a degree in engineering to install an MSD ignition. Just some minor wiring skills and common sense are needed to install a complete system.

An aftermarket ignition can go a long way in improving the performance of your 5.0. The stock Ford ignition system will do fine with a bone-stock engine, but as soon as you start adding performance pieces, an aftermarket ignition system will be necessary to keep up with the extra spark demands needed to feed upgrades such as intake, heads and cam. If you plan to go the power-adder route, you will definitely need to install an aftermarket ignition. If you don’t have the most optimum spark available for power adders, you’ll definitely be hurting parts in short order.

MSD has been producing ignition systems for years and if you’ve ever watched NASCAR racing, those boys rely on MSD ignition components in their cars, so that tells you something about the quality of their stuff. Furthermore, MSD has several ignition system components directly tailored toward the 5.0 Mustang.

The MSD ignition system we’re installing is called the Digital-6 Plus. The D-6 Plus uses a high-speed RISC microcontroller to control the ignition’s output while constantly analyzing the various inputs such as supply voltage, trigger signals and rpm. The microcontroller processes all this information and can make quick compensations to the output voltage, multiple spark series, timing and rpm limits while maintaining accurate timing signals to within 1degree and 1 percent of the rpm limits.

Enough technical talk, let’s get started. Before installation, disconnect the battery cables. Remember—when disconnecting the battery cables always remove the negative cable first and install it last.