With over 25 years on the engine and nearly all of its associated components, Project Rehab is definitely in need of a few upgrades under the hood. Although we performed a very basic tune up when we first bought this car, the ignition system has definitely seen better days. There’s excessive play in our distributor shaft, plus we’re not sure how strong the stock coil is. Even the year old Motorcraft spark plug wires we picked up don’t really fit the car all that well. For help getting our ignition system back in order we turned to Performance Distributors.
Performance Distributors sent us everything we need to update and upgrade Project Rehab’s ignition system and spark some life back into our little stock 5.0. They sent us a new Hot Forged distributor, part number 18457BL, a set of their LiveWires spark plug wires, part number DUI-C9057BL, and a new Screamin’ Demon ignition coil, part number 31724.
The Screamin’ Demon Coil delivers more power to our spark plugs. Rated at 45,000 volts, this coil will allow us to open up our spark plug gap by an additional .010 to .015 of an inch. This yields more complete combustion giving an increase in horsepower and torque. An added benefit is also better starting and smoother idle as well as improved throttle response.
Another cool feature of the Screamin’ Demon is that it fits in the stock coil bracket. There’s no need to fabricate something new up, or even hack into the factory harness to make new connections. The Screamin’ Demon is a perfect fit and accepts the factory coil connector in the factory harness.
Left: The original 1988 coil out of Project Rehab. Right: The Screamin' Demon coil mounted in the cleaned up stock bracket in the stock location.
All that additional ignition energy requires a way to transmit it to the spark plugs. Performance Distributors recommends a set of their LiveWires for this task, and that’s what they sent us.
LiveWires aren’t your ordinary parts store plug wires. These use an 8mm spiral core made up of a stainless steel wire wrapped around a magnetic core. The result is outstanding power transmission to the spark plugs with incredibly low resistance. “Our tests show that you hit a point of diminishing returns regarding resistance. Spark quality and performance is not enhanced once a certain level of resistance is reached. Our tests indicate that range is 250-350 ohms per ft,” says Performance Distributors Steve Davis.
Davis says they could make a wire with as little as 50 ohms per ft resistance but it would only add to the cost without increasing the wire’s performance. Davis also recommended replacing the wires as part of an ignition system upgrade since wires with high resistance may not be able to carry the hotter spark and won’t allow owners to take advantage of the other upgrades.
This LiveWires design also acts as an RF interference suppressor, meaning that the LiveWires won’t interfere with radio or other electronics on the car.
Top Row: Left: Our original ignition system has seen better days, even with a tune up just last year. Center: To remove the distributor we disconnected the harness connector from the module. Right: We bumped the starter (you can also turn the crank by hand) until the rotor was pointed to 12 o'clock. Doing this will allow us to get the new distributor installed close enough to fire the car up and set the timing appropriately. Bottom Row: Left: A distributor wrench is used to remove the distributor hold down clamp. Center: We removed the distributor by carefully pulling it up, watch for the oil pump driveshaft, you don't want it to come out too. Right: We didn't replace the rotor last year, and it's showing wear.
Our new hot forged distributor with Dyna Mod ignition module is a direct drop-in replacement.
Since Project Rehab is still running an old school pushrod 5.0 we needed a mechanical distributor to direct the spark energy to each plug. The Performance Distributors Hot Forged DUI distributor is a direct drop in replacement for the factory unit.
Made from hot forged 6061 aluminum this is one tough distributor. According to Davis the hot forging process allows the aluminum to maintain its grain flow resulting in a denser, stronger distributor. Performance distributors tests each of these units for thermal shock and RPM accuracy all the way up to between 8,000 and 10,000 rpm. We won’t ever be taking Project Rehab’s engine into those kinds of RPM ranges, but its nice to know that when things are shaking just before a shift at the drag strip we’ve got a distributor under the hood we can count on.
Top Row: Left: We used the provided lubricant to thoroughly lube the distributor gear prior to installation. Center: The new Hot Forged distributor drops right in like it always belonged there. Right: Our rotor is as close to 12 o'clock as we can get it. Bottom Row: Installing the plug wires is easy. The distributor cap is marked for cylinder number one and the rotor will spin counter clockwise. Cylinder number one is the closest to the radiator on the passenger side of the engine with 2, 3, and 4 on that side, cylinder five is the closest to the radiator on the driver side with number eight being the one closest to the firewall. All 5.0 HO engines in Fox body Mustangs use the firing order, 1-3-7-2-6-5-4-8.
Performance distributors numbers each wire for its corresponding cylinder, taking any guess work out of the installation.
Davis also says that the shims used for determining end play in the distributor shaft are determined with a micrometer, there’s no guessing or one size fits all approach. They also use brass terminals on the distributor cap and rotor, “A brass terminal cap provides improved conductivity of the spark. The stock aluminum terminals aren’t as conductive,” says Davis. Performance Distributors also includes a steel distributor gear already installed which is the proper gear for hydraulic roller engines.
Also attached to the Hot Forged distributor is the Dyna-Module. “The Dyna-Module has more dwell time than the stock module by 2 to 3 degrees throughout our the rpm range.” Davis explains why more dwell is a good thing. “A longer dwell time allows whatever coil you’re running to saturate longer and build up a hotter spark. In the old breaker point style ignitions this was done by switching from single to dual points. In modern systems the dwell is set by the ignition module or the computer.” Working with the Screamin’ Demon coil, and the Live Wires, this is a recipe for more horsepower, crisper throttle response, and better starting.
Left: The spout connector must be disconnected prior to setting the timing. On Fox body Mustangs it's always near the distributor harness and is typically a black square plug, pull one end out and keep track of it. Right: With the engine warmed up we used a timing light to set the base timing at 14 degrees. (34 degrees total)
Installing these parts is about as easy as performing a tune up. We’ve outlined the installation and tips in the photos and captions we included with this story. The entire process can be completed in less than two hours on cars that are completely stock, and in our case less than an hour when there’s very little in the way impeding our progress.
With our ignition upgrades in place we opened our plug gap up to .055 and set our timing to 14 degrees using a timing light. We’re still waiting on wheels and tires to come in for Project Rehab so a test drive was out of the question. What we can tell you though is that the car fires up faster, there’s no more of the wawawawah waiting for the ignition system to light things up, and some quick raps of the throttle proved very satisfying. We can’t wait to take the car for a test drive and down the drag strip with our new upgrades.