Ideally, every performance part you add to your Mustang would increase performance, improve appearance, and be easy to install. Of course, the more seasoned veterans know this sort of mechanical symmetry rarely exists.

Before-and-after chassis-dyno...

Before-and-after chassis-dyno tests were conducted at WestechPerformance Group in Mira Loma, California. Installation of the Accufabthrottle body assembly netted an impressive 13 hp at the rear wheels--notbad for an hour's work.

1 (left and right) The stock...

1 (left and right) The stock throttle body bolts to a cast-aluminum elbowassembly, which in turn is mounted to the side of the supercharger case.Rather than simply developing a bigger, better throttle body, Accufabalso developed a cast- aluminum elbow that outflows the stock piece by areported 250 cfm.
Peak Horsepower: 382.1 at 6,200 rpm
Peak Torque: 380.2 at 3,885 rpm
Peak Horsepower: 395.2 at 6,340 rpm
Peak Torque: 379.8 at 4,000 rpm
As are the throttle bodies for the 5.0 engine that made Accufab famous, this '03 throttle body is made from billet aluminum and is polished to a high luster (it's also available in a satin finish for a more OEM appearance). But this kit also comes with a cast-aluminum replacement for the Cobra's restrictive inlet elbow. The two pieces come preassembled and include the necessary gaskets and hardware. The kit sells for $599.99 with the polished elbow and $579.99 for the powdercoated elbow.
Horse Sense: Accufab is best known for its line of polished throttle bodies, but it also offers a variety of other products, including a 4.6 cog-drive system for centrifugal blowers, a modular honing and deck-boring plate, a 460 swap kit, and even an 8.8 diff girdle.
We recently visited Accufab Racing in Ontario, California, to observe the installation and chassis dyno test of its new throttle-body assembly. If you're one of the lucky few to own an '03 Cobra, this is one performance addition you can't do without.
Happily, the folks at Accufab have developed a new throttle-body assembly for the '03 Cobra that satisfies all the hot rodder's needs. It increases rear-wheel horsepower by 7-10 hp on average, it looks great, and it installs within an hour using common handtools.

2 Accufab makes the '03 Cobra...

2 Accufab makes the '03 Cobra throttle body assembly in bothpolished (shown) and factory powdercoated finishes. Note the smoothercontours of the Accufab elbow.

3 The first step is to disconnect...

3 The first step is to disconnect the battery before performingany work on the Cobra's engine. Then, disconnect the breather hose fromthe valve cover, loosen the clamp that secures the intake ducting to thethrottle body, and pull the intake duct away, as shown.

4 Pop the cruise-control...

4 Pop the cruise-control cable off the throttle body linkage(simply pull on it and it unsnaps). Rotate the throttle body linkage tothe full open position, and pull the throttle cable free.