This month's story about the Project Unfair '69 Camaro is going to look different, because big stuff like the body modification and suspension installation are done. Well, almost done. It's time to figure out all the initial-wiring and plumbing fabrication. It's time to look at some of the small stuff. According to Frank Serafine, owner of Prodigy Customs, "Many first-time builders go straight to paint after getting the body modifications squared away. That's a mistake, because wiring and plumbing requires lots of drilling and welding. It's really a lot better to figure all that out before the bodywork gets done."
John Parsons, Frank's partner in the project (and owner of II Much Fabrication) specializes in high-end wiring, plumbing, and exhaust, and so this month's action takes place at John's small shop across town.
John and Frank are building the wiring system around a 12V Braille lithium battery, the ML30. It has a staggering 1,300 cranking amps, but weighs less than 10 lbs. Lithium is the newest technology for high-end batteries, and Braille pioneered it for racing teams around the country. Lithium charges faster and maintains higher voltage under load than traditional batteries. That will allow the Holley Dominator EFI to see a solid 12V for the coils and injectors while the starter is cranking the engine. EFI controllers get unhappy when voltage drops below 10V during cranking. Some builders resort to running dual batteries, but the Braille should handle all of it with ease.
Unfair is using Holly's new Dominator EFI for engine management. Its latest and best EFI controller yet, Holley learned a lot from the older Commander 950 EFI controller. All that is packed into the Dominator. Available now, it supports the native LSX cam and crank sensors, as well as direct support for GM's coils and injectors. Naturally, it supports a whole lot more than that, and we'll see more when we cover the engine build.
RaceLogic's traction control system will be used to keep the car moving forward instead of just sending the rear tires up in smoke. It works by using factory GM ABS wheel sensors to detect when the rear wheels are spinning faster than the fronts. It cuts engine power by dropping individual injector signals so there isn't any fuel to burn in a particular cylinder in that revolution. The cut signal moves around to keep the engine from missing too badly until traction is restored. The ABS controller is from a late-model Corvette Z06. It incorporates a steering-angle sensor, yaw sensor, brake-pedal sensors, and line-pressure sensors, along with the wheel sensors it shares with the RaceLogic box.
All these components will be integrated with American Auto Wire's (AAW) Highway 22 master panel and accessories. The Highway 22 is so-named because it supports 22 separate circuits, plenty for project Unfair, even with all the advanced features John and Frank have planned. Under the covers, the Highway 22 is wired with heavy-duty connectors and heavy gauge wires. As Mike Manning of AAW, put it, "The 22 is over-engineered, and could be used to power three cars. It's perfect for Unfair."
We're not going to show you a boring "connect this wire to that connector"-type article, but instead highlight some of the advanced techniques John used for bulkhead connectors, harness connections, system disconnects, box location, and wire routing.
John uses Delphi Metri-pack connectors (the same as GM) for most harness connections. They are easy to assemble and crimp, and easy to connect and disconnect when complete. For bulkheads (no grommets allowed in Unfair!), he uses Molex XRC connectors. They are very similar to a mil-spec connector, but are about one-quarter the cost, use a more traditional crimp, and can be disassembled when you make a mistake. The key to using bulkhead connectors is keeping track of every single wire, and writing it all down in a table that can be referenced by wire color, connector location, and intended purpose. Amperage ratings are important to factor in as well: the XRC connectors are rated to 14g wire/13 amp current. Higher current needs will have to go through the more traditional large bulkhead connector that can carry 10g wire and 40 amps.
Grouping wires together in visible locations (like under the hood) is traditionally done with wraps of wiring tape or split loom plastic tubing. Those are ugly and bulky. Instead, John uses nylon mesh held in place with shrink wrap. It makes for a tidy and flexible way to run bundles of wires together, without having to use tie wraps every 4-5 inches to keep individual wires from drooping out of the harness.
As we said, this won't be about connecting the gray wire to the yellow wire. Instead, follow along as John shows off some of his techniques for building a safe, reliable, and easy to service wiring harness.