Marc Christ
Brand Manager, Modified Mustangs & Fords
June 1, 2013

There's no arguing that the '11 5.0L GT is raising the eyebrows of even the most hardcore Mustang enthusiasts. With a 412hp rating, it's more powerful (as rated by Ford) and just as quick as a stock Terminator Cobra. The still-popular Terminator had a little help from an Eaton twin-screw supercharger, while the '11 GT is powered by a naturally aspirated 5.0L Four-Valve powerplant.

Almost eight years ago, MM&FF installed BBK long-tube headers, a 2.5-inch after-cat system, and a high-performance air filter, and removed the silencer on an '03 SVT Cobra ("Moving Air," Dec. '02). These few simple bolt-on parts yielded 55 rwhp and 37 lb-ft of torque. So how does the '11 GT respond to similar mods?

First, we called on Jake Lamotta of Lamotta Performance in Longwood, Florida. He was more than willing to provide his '11 GT for the test. "As long as I don't have to cut or drill anything, I'll put whatever you want on this car," Lamotta told us when we approached him about the install. So with our vehicle locked in, we patiently waited for the first bolt-ons to become available.

The first phone call we received was from Anthony Grosser at Stainless Works (SW). He called to tell us that SW had an entire exhaust system-headers to tailpipes-available for the '11 GT. SW is known for its quality and fitment, so we were excited to see it's new product in action.

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The headers utilize 3/8-inch laser-cut flanges, 1 7/8-inch primaries, and a 3-inch collector. "It's a slip-fit connector with an integrated merge spike," Grosser explained. The long-tube headers (PN M11HDR) retail for $950 and fit both manual and automatic applications. We opted for the headers with catalytic converters and lead tubes (PN M11HDRCAT), which retail for $1,450 and work with either the stock exhaust system or the SW system. There's also an off-road option (PN M11HDROR), which sells for $1,150.

The rest of the system is made of the same high-quality 304 stainless steel. "The exhaust is fully mandrel-bent with an X-style mid-pipe, which helps with scavenging," Grosser said. The mufflers are made in-house at SW and are available in three different variations. We chose the kit with the chambered muffler (PN M11CB3) because it's the quietest. All three versions of the after-cat system sell for the same price-$1,050.

While waiting on our exhaust components, we found out that C&L Performance was almost done with its development of a cold-air intake. We called Lee Bender of C&L to get our hands on one for this test. Bender was nice enough to rush us a pre-production model, but by the time this issue reaches your mailbox or newsstand, the production model will be available.

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"From our testing, we've found that the factory air intake assembly for the '11 GT flows 748.7 cfm, which is a reduction in airflow of approximately 50 cfm versus the factory '10 GT air intake assembly, which flowed right at 800 cfm," said Bender. "This difference is due to the fact that the new vehicle now features a single round throttle body that is placed lower in the engine compartment. The new inlet tube is both smaller and has a different airflow path, which makes it more restrictive than the one that was used on the '10 GT models."

So Bender and the rest of the C&L team designed a new cold-air intake to replace the stock piece. What they came up with was a kit that flows over 1,100 cfm, a 45 percent increase over the stock piece. It features a filter housing, a high-flow air filter, a mass air meter housing that accepts the stock mass-air meter, an inlet tube, and all the hardware necessary for installation.

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