February 28, 2007

Let's review automotive theory, if you will. A Mustang, just as any car, is comprised of a series of systems. There's the electrical system, the suspension system, the ignition system, and others. Together, these all collaborate to make the car function as it should; without most of them, a 'Stang would be nearly inoperable.

Now that the engine and transmission are in place in our '86 T-top coupe ("Lowering the Vroooom," March '07, p. 142), we're at a point in the Mustang's reconstruction where we can start taking care of the must-do development of the systems that will make our car work.

The T-top coupe's fuel, air-induction, exhaust, and cooling systems are critical to how its Paxton Novi 2000-blown 347 will operate in the real world. The 'Stang's brake system is another vital element of its overall grand scheme, since we'll be counting on it to slow down our beast from break-neck speeds at the track.

Fabricating and routing stainless steel, braided-, and hard-line hoses, as well as stainless tubing, are the tasks at hand for this segment of our build effort. The systems we're creating allow various fluids and gasses to travel to and from the points they need to reach throughout the car. This development of flow circuits is known as "plumbing" the Mustang, and, in theory, it doesn't differ much from laying out the myriad of pipes and fittings that move water, heat/air conditioning, and exhaust in most homes and buildings.

We're fortunate enough to have some of the best in the high-performance-plumbing businesses based in Southern California, and we called on them for assistance with a few of the systems being covered in this report. Special thanks are a must for Bent Custom Plumbing and Sheetmetal, Fab-Tech Custom Fabrication, Fast Intentions Performance Exhaust, Galpin Auto Sports, JBA Performance Exhaust, Saul "The Surgeon" Gutierrez, and Orme Brothers Hose and Fittings. Everyone made adjustments in their schedules to accommodate our project and meet the critical deadlines.

Plumbing a 'Stang is physically and mentally taxing. It's hard on the body installing tubes in hard-to-reach areas, especially if you don't have the luxury of a shop or tools that make it easier; it's also hard on the mind trying to map out where and how things should be routed in the car so it looks good, and, more importantly, functions well.

When plumbing your 'Stang, keep bends in the lines and tubes to a minimum. The shortest distance between two points is a straight line, and that theory is important when it comes to the way certain properties move in, around, and out of a car. Knowing what to use for the different types of plumbing systems in your 'Stang-hose diameters, pressure ratings, material, and so on-is also important.

This project is about using the right stuff to build our street/strip 'Stang, and showing exactly what comprises the right stuff and how to use it. Remember, we've been building our coupe with a Drag Week (five-day/1,500-mile, real-world street/strip endurance challenge) mentality, so we've set an unofficial minimum 300-mile-per-day standard that every aspect of the car must meet.

Follow along as we work on getting our four-eye's flow right.

FuelThe fuel system is the liquid lifeline for any car, and we're making sure the plumbing for our ride's fuel delivery is topnotch. We've already given you the lowdown on the 14-gallon fuel tank by Rick's Hot Rod Shop that incorporates Aeromotive's 600 lb/hr, A-1000 EFI fuel pump and 100-Micron fuel filter inside it ("Tech Inspection," Jan. '07, p. 180), but there's a lot more to the fuel system that needs to be highlighted.

From the tank, AN (this stands for Army/Navy) -8 fittings and a steel-braided hose is used for feeding fuel forward. The -8's diameter is about 131/432 of an inch, which is the minimum recommended for 300-, to 600hp power-adder applications. Full-on race cars use AN -10 line that is approximately 11/42-inch diameter for fuel delivery, as more exotic combinations count on getting every bit of fuel volume possible.

The main fuel line passes through a Barry Grant fuel cooler, then flows into a Y-block by Overkill Performance. The Y-block divides the fuel feed across two lines that supply the Aeromotive fuel rails and RC Engineering 650cc injectors sitting atop the 347's intake manifold.

We're setting up the coupe's fuel system as a return-style deal, meaning fuel that isn't metered through the injectors circulates through Aeromotive's A-1000-6 bypass regulator and back to the tank. This process keeps fuel flow steady-especially under hard accelerating and braking-and it will also keep the fuel's temperature cooler when we drive the coupe on the streets and freeway.