Today there are all kinds of options when it comes to upgrading the performance of your car. Two of the most common, it seems, are a cold-air intake and an aftermarket exhaust. Granted, a lot of Fords in recent years have benefited from reasonably efficient factory pipe and muffler systems, but there's always room for improvement. Take the case of the late and lamented Mercury Marauder. Spun off the evergreen Grand Marquis fullsize sled, the Marauder was a proper-sized muscle car, the likes of which hadn't been seen since 1970. A lot was promised initially, including a supercharged Two-Valve 4.6 engine, and even a concept two-door convertible was built. As this car emerged, it was powered by a version of the '03 Mustang Mach 1 engine that, while exotic for a muscle car, didn't have the low-end oomph to get one of these near-4,200-pound beasts moving off the line at a torrid pace.
High Is Good, But We Want Low
Yours truly remembers testing one of these cars when they were new. Whilst a bit slow to start, the cammer engine came into its own above 3,500 rpm. Unfortunately, it was a bit too late to really get the advantage in the whole 1,320 grudge match, the kind of thing muscle cars were really built for. Our testing of the day (without cheating, I might add) yielded a string of low 15- and high 14-second e.t.'s. On numerous occasions our test victim was run against its arch-rival, the '94-'96 Impala SS, which had 79 more cubic inches, and our Marauder's 60-foot times were slower. By the time we really got up to speed, we ran out of track. So while the mph was consistently higher than the big Chevy's, our e.t.'s remained slower-we couldn't have that.
Gary Keilhauer, a product specialist at Donway Ford SVT in Scarborough, Ontario, felt the same way. He liked the look of the Marauders ever since he first laid eyes on one and just over a year ago hit pay-dirt when he picked up a low-mile mint example for a reasonable sum. However, like us, he felt the car needed a bit of extra va-vavoom, so he sat down and contemplated a few upgrades. We've said since day one that this car needs a tune, an exhaust, and 3.73 gears to make it really fly. All the basics were already in place. Keilhauer, wanting to add a bit of excitement, decided he'd begin his journey down that road, but considering the car was a daily driver, he left out the gears initially. That meant an exhaust upgrade and a custom tune were still in order. Would they provide the extra thrust and power he was looking for? Let's find out, shall we?

Before we began the install,...

Before we began the install, it was a good idea to baseline the car on a rolling road. We took it to DaSilva Racing in Pickering, Ontario, and strapped the big Merc down on the rollers. With 91-octane fuel in the tank, we did a baseline run in bone-stock configuration and were rewarded with 234 hp and 254 lb-ft of torque on the shop's Dynojet 248. Considering this is a heavy car, we could use a bit more grunt.

With the stock power and torque...

With the stock power and torque levels established, we knew what our target was. Achieving this isn't always as easy as you might think though (we've seen cars actually lose both power and torque with aftermarket exhaust systems). Enter NoyzBoyz Performance Exhaust. These guys have gained an enviable reputation for producing custom exhaust systems that work and last. Owner Sav Mitas has been in the custom pipe game for years, and his proven formula means customers keep coming back.

When we got the car to the...

When we got the car to the shop, Mitas himself was on hand to inspect the car and give a few pointers. The biggest area of improvement, he felt, would be found in the mid-pipe and mufflers. He advised against putting headers on the car at this point. His argument was hard to ignore, so Keilhauer decided he would replace the exhaust from the manifold flanges back.

As it stands, the Marauder...

As it stands, the Marauder comes with a pair of log-style cast-iron manifolds. These feed into a double Y-pipe with a crossover tube. From the factory, this Y-pipe is 2 1/2 inches in diameter but incorporates four catalytic converters: two pre cats right up by the manifold flanges and two cats downstream. The end of each converter is actually 2 1/4 inches across, and although the system works reasonably well, it hinders flow, especially considering that the four-cam engine really likes to breathe.

At the rear, behind the Y-pipe,...

At the rear, behind the Y-pipe, the Marauder features dual tubes that route into 2 1/2-inch mufflers and then into big 3-inch polished Meg's tips. The stock mufflers are fairly quiet and Keilhauer wanted something that would give the car a more velvety rumble, in keeping with its sinister looks.

The first task was to carefully...

The first task was to carefully remove the oxygen sensors on each side before unbolting the stock mid-pipe assembly and putting it aside.

With that out of the way,...

With that out of the way, work on the mid-pipe assembly began. To ensure a perfect fit and improved flow, the Merc received a custom X-style crossover with high-flow Magnaflow cats in place of the stock setup.

NoyzBoyz features its own...

NoyzBoyz features its own pipe-bending machine, so the 409 stainless steel tubing can be bent into shape and flanged.

We get the old system removed...

We get the old system removed from the car using a reciprocating saw in a few select locations.