Project MILF 2006 Ford Mustang GT Exhaust Install - Waiting To Exhale

The real question is, did the increase in power translate into quicker times at the track? You bet it did, as MILF went from a previous best of 12.66 at 107.73 mph to a stout 12.47 at 110.00 mph, and it did so in worse weather conditions. Without a doubt, Project MILF has a presence on the road, though it's still docile enough to haul the kids around. Maybe we should change the acronym for MILF from Mustang I'd Like to Flog to Mommy Is Lightning Fast.

With The exhaust manifolds...        read full caption With The exhaust manifolds out, it was time to put in the long-tube headers. The passenger side was pretty straightforward, but the driver side proved to be extremely difficult. Once the headers are in, don't forget to lower the engine and tighten the steering rack and motor mounts.

After The headers were on,...        read full caption After The headers were on, the midpipes and the cats went on. Once the cats were on, the x pipe system and the rest of the tubing was mocked up.

Since Everything looked good,...        read full caption Since Everything looked good, Winter started to final-assemble the system one piece at a time. For the record, each piece of exhaust tubing is marked for either the right or left sides, as are the mufflers.

With all of the tubing in...        read full caption With all of the tubing in place, Winter tightened down the exhaust clamps one at a time. This is what the finished product looked like.

The Final piece of the puzzle...        read full caption The Final piece of the puzzle was the installation of the mufflers. The muffler hanger had to be removed from the frame on each side and swapped around as the brackets were welded on the Stainless Works muffler opposite the way they were welded on the factory mufflers.

Last But not least, on went...        read full caption Last But not least, on went the tips. Winter then aligned them using the good, old Ford tool: the beater bar. In actuality, he massaged the muffler brackets until they were in the correct position and allowed the tips to line up perfectly.

Rolling Thunder
To Quantify how effective the long-tube headers and exhaust system were on Project MILF, we did a pair of before-and-after dyno pulls on Crazy Horse Racing's Dynojet chassis dyno. With the stock exhaust manifolds, cats, mufflers, and 211/42-inch exhaust tubing, the car pumped out 328.9 rwhp and 287.4 rwtq. After installing Stainless Works' 131/44-inch long-tube headers, high-flow cats and mufflers, and 3-inch pipe, MILF upped the power number slightly to 330.2 rwhp. The torque number saw a significant increase, as it moved to 304.8 lb-ft. If you do the math, that equates to a 1.3 rwhp and 17.4 rwtq increase.

The peak numbers do not tell the full story, however. If you look at the curves, the headers and exhaust system show an increase of both torque and power above the stock system starting at 4,200 rpm. This increase will help the car throughout the entire quarter-mile, and it's something you will definitely feel in the seat of your pants.

Now, you might be sitting there muttering to yourself, Didn't this car make 335 rwhp and 308 rwtq after the Whipple blower was put on? The answer is yes-and no. When the dyno tests were performed after the supercharger was on, compared to the runs made after the exhaust was installed, the air was much different. Cooler air makes more power, and that is what we had when we dyno'd the car with the blower. Even though the dyno compensates and corrects, it's a good idea to get a new baseline before each change. That's why we rebaselined MILF the day of the install. Nevertheless, the real dyno is the racetrack, so that's where we headed next.

With The exhaust in its final...        read full caption With The exhaust in its final position, Winter set about reinstalling the O2 sensors. Once the sensors were in, he installed the supplied O2 sensor extensions.

Remember That debacle we mentioned...        read full caption Remember That debacle we mentioned earlier? Well, here it is. In trying to remove the O2 sensor from the driver-side exhaust manifold, Winter realized that when it was installed on the assembly line, it was cross-threaded, thus ruining the sensor. Naturally, we got a new one.

Before He mated the tubes...        read full caption Before He mated the tubes to one another, Winter slipped the provided clamps over the tubing ends.

To Keep the exhaust system...        read full caption To Keep the exhaust system in the desired position, Winter used this support jack, which he placed under the center of the x pipe system. Once the system was tight, the support was removed.

Winter Felt that the system...        read full caption Winter Felt that the system was still a bit too loose for his liking at each joint, so he fired up his welder and tack-welded each joint. He welded only the back of the x pipe system because we are contemplating swapping out the factory converter in a future installment. If he was to weld each joint, he would only have to cut the joints at the front of the x pipe system later. Once the joints cooled down, he hit the welds with a wire brush and then some black paint.

While We picked up only a...        read full caption While We picked up only a little under 2 rwhp and 17 rwtq on the dyno, the midrange gains allowed Project MILF to hustle to a 12.47-second best with a trap speed of 110 mph. The Stainless Works headers and exhaust netted us a speed increase of more than 2 mph and a decrease of nearly 0.2 second when compared to what we ran with the stock system. Overall, with the FRPP Super Pack and the Stainless Works exhaust system, Project MILF has picked up nearly 10 mph and dropped more than a second in elapsed time.