BBK's new headers for '05-'07 Mustang GTs come with all the usual related installation har
Now that we're well into the third year of production for the S197 Mustang, the aftermarket and legions of owners have had plenty of time to figure out that these cars respond quite well to bolt-on upgrades. Better, in fact, than probably any previous Mustang generation.
Not one to be left behind in the evolution of 4.6 Mustang development, BBK Performance Parts has been right there every step of the way. This is evident by the impressive results we achieved last year when installing a few BBK bolt-on bits on an '05 GT.
In a nutshell, BBK's throttle body, cold-air kit, and underdrive pulleys netted a 30hp gain over the car's baseline, and keep in mind that this was at the rear wheels, not at the flywheel. At the flywheel, call it nearly 50 hp. Not bad for a few hours work and about $1,000 in parts and installation labor-even less if you do the installation work yourself.
This time we're turning our attention to the exhaust side of engine breathing by installing BBK's new shorty headers for the three-valve, 4.6-powered Mustang GT. The results are a worthwhile step on the path to more bolt-on power.
Note that we only installed and tested the headers themselves. This includes the '06 GT test car's stock mufflers and H-pipe. Combine the headers with BBK's soon-to-be-released crossover pipe and the other above-mentioned items, and more than 300 hp at the wheels will easily be the result. It's a setup we look forward to doing, and we intend to pass on the results when a BBK test car is complete.
While having a hoist makes the job easier, it can be done with a pair of sturdy jackstands
On both sides of the engine (passenger-side shown here), remove the nuts that hold the fac
On the driver-side of the engine, remove the bolt that secures the oil-dipstick tube to th
Although it might be considered optional, we strongly recommend taking the following steps
From here, the work is mainly underneath the car. The next step is to remove the H-pipe. S
Pry up the locking tabs with a small screwdriver while sliding the clamps toward the rear
There are four oxygen sensors, one of which screws into the driver-side manifold. Unplug a
The H-pipe is then unbolted from the stock cast-iron exhaust manifolds.
With the oxygen sensors unplugged and the H-pipe separated at the front and rear, its moun
With the H-pipe removed, there's some working room under the car. Continue removal of the
With both bolts loosened, the steering shaft comes right out. Be sure the wheels are turne
At this point, the engine can be raised since the motor-mount bolts were removed in Step 4
Motor-mount removal is simple: Remove the four bolts that hold the ear to the side of the
With the bolts removed, the motor-mount ear lifts out. The design and engineering of the n
Most of the nuts on the bottom side of the manifold are best accessed from under the car.
Unbolt the starter to allow the passenger-side manifold to come out. Remove three bolts an
As with the driver-side, the passenger-side manifold comes right off once all the fastener
Compare the stock passenger-side manifold with the passenger-side BBK header, and it's cle
The oxygen sensor needs to removed from the factory manifold and reinstalled on the driver
The headers and new gaskets fit in place of the stock manifolds. Although BBK supplies a c
There might be an instance where a stud needs to be removed to fit the header because it e
With the motor mount and starter out of the way, the passenger-side header also installs d
Reinstall the H-pipe and plug the oxygen sensors back into place to complete the job.
On the Dyno
If you only look at the peak horsepower gain, shown in bold numbers, then sure, the headers only gained 4 hp at the wheels. But you'd be missing the large majority of what the headers really did for our '06 Mustang GT test car.
Study the dyno charts to discern the real benefits of the BBK headers: improvements in torque output. For example, look at the results at 3,000 rpm. The car in the baseline test made 265.6 lb-ft. With the headers, the figure jumped to 283.2, an improvement of 17.6 lb-ft.
Torque is what you feel on the street, and having more of it in the midrange is what's important for slipping through traffic and getting up freeway on-ramps. At various speeds, power output isn't too bad either. Again looking at 3,000 rpm, the baseline test result is 151.7 hp. With the headers in place, output jumped to 161.8 hp for a gain of more than 10 hp.
Additionally, recall that we're only testing the headers here. With BBK's crossover pipe in place, figure another 10 hp or so improvement across the board or well over 300 hp at the wheels on this car already equipped with a BBK throttle body and cold-air kit. Note too that the power and torque peaks with the headers were at slightly lower engine speeds, which makes the power all the more usable on the street. Furthermore, with the headers, the torque curve stayed over 300 lb-ft from 3,750 all the way to 5,000 rpm, another notable improvement over the baseline test.
|Baseline: '06 Mustang GT with |
BBK throttle body and cold-air kit
|RPM ||POWER ||TORQUE |
|2,250 ||114.0 ||266.2 |
|2,500 ||127.3 ||267.5 |
|2,750 ||139.3 ||266.1 |
|3,000 ||151.7 ||265.6 |
|3,250 ||166.0 ||268.2 |
|3,500 ||188.1 ||282.2 |
|3,750 ||207.7 ||290.9 |
|4,000 ||229.9 ||301.9 |
|4,250 ||246.5 ||304.7 |
|4,500 ||261.4 ||305.1 |
|4,750 ||271.2 ||299.8 |
|5,000 ||284.2 ||298.5 |
|5,250 ||292.2 ||292.3 |
|5,500 ||292.4 ||279.2 |
|5,750 ||292.0 ||266.7 |
|6,000 ||291.0 ||254.8 |
|BBK headers |
|RPM ||POWER ||TORQUE |
|2,250 ||118.3 ||276.0 |
|2,500 ||131.9 ||277.0 |
|2,750 ||148.0 ||282.8 |
|3,000 ||161.8 ||283.2 |
|3,250 ||175.5 ||283.6 |
|3,500 ||197.9 ||296.9 |
|3,750 ||214.7 ||300.7 |
|4,000 ||236.0 ||309.8 |
|4,250 ||255.6 ||315.8 |
|4,500 ||270.0 ||315.1 |
|4,750 ||279.9 ||309.5 |
|5,000 ||291.9 ||306.6 |
|5,250 ||296.4 ||296.5 |
|5,500 ||286.2 ||273.3 |
|5,750 ||286.8 ||262.0 |
|6,000 ||286.9 ||251.1 |