2001 Ford Mustang Bullitt - Wildcatting Bullitts

Actually bolting on the Accufab throttle body is simple stuff. Don't forget to set the Throttle Position Switch with a digital voltmeter, otherwise you may end up with funny throttle response, a high idle speed, and other irregularities. Because the large single-blade throttle of the Accufab design opens so much more area more quickly than the stock two-blade throttle body, off-idle driveability is a bit touchier. John says some Mustangs accept the big throttle body without complaint, while others seem to take a fair amount of fiddling and time for the computer to readjust before the idle drops that last 150 rpm or so. Cobras are finicky in this regard, and the Bullitts are worse, according to John.

Baseline: Internally stock Bullitt 4.6 GT with Vortech supercharger, Vortech aftercooler, and 8 pounds of boost Spark Plugs: Engine as in Baseline, but with Denso IT20 Iridium spark plugs Exhaust: Engine as in Spark Plugs, but with MagnaFlow exhaust system Throttle Body: Engine as in Exhaust, but with Accufab throttle body

Because the Accufab throttle body offers an unobstructed air path, but the stock Bullitt upper intake tube does not, it is necessary to mark the intake, unbolt the upper tube from the rest of the manifold (in back, near the firewall), grind out the aluminum in the center, then refit the intake tube. The marking is easy-just hold up the Accufab throttle body to the intake and draw its outline on the mating flange. Reaching the four bolts holding the intake tube to the rest of the intake requires more effort, as John Mihovetz is about to demonstrate here. Once again, 11/44-inch drive sockets and extensions come in handy for this job. Note also that FRPP intakes, which are similar to Bullitt intakes, dive more between the throttle bores, and they cannot be ground out as deeply.

Once the intake tube is on...        read full caption Once the intake tube is on the bench, grinding out the center obstruction is easily done with a carbide tip and either an air or electric grinder. Westech's Steve Brule, who did the honors, is partial to this electric grinder because of the angle of its grips.

Even Accufab owner John Mihovetz...        read full caption Even Accufab owner John Mihovetz didn't recall the measured size on his $369 oval throttle body for Cobra, FRPP, and Bullitt 4.6 intakes. "We just call it the elliptical," he smiled. It's definitely larger than the twin-blade stocker and has to offer less restriction to the incoming air. John says his throttle body delivers 6-7 hp on naturally aspirated Bullitts. It yielded 12 hp on Mark's supercharged example in our testing.