Elisa Coon
June 1, 2013

Watching the great strides performance shops have made with the 5.0L Coyote platform over the past year, my husband and I just had to add one to our stable. We'd recently sold our boosted Three-Valve GT, and needless to say, we were pretty stoked when our shiny new '13 5.0 Mustang arrived—we just couldn't wait to get the wrenches turning. The seat-of-the-pants feel was impressive and it roasted the tires like it was ready to blaze some 12-second passes—we officially had 5.0L fever.

With a whirlwind of induction options and modifications that have recently hit the market for these new-school beasts, picking the right bolt-on boost wasn't easy. Our main goal was to keep it looking as factory as possible. We also had power goals in mind, and didn't want to limit ourselves with a supercharger that would be maxed out before putting the car in the 9-second zone in the near future. We opted for the Phase Two Roush supercharger kit (PN 421390), retailing for $6,599.99 and rated at 625-flywheel horsepower—more than enough to get your adrenaline flowing.

In this article, we cover Phase One of the installation—the 525hp kit (PN 421388), retailing for $6,099.99. Roush is currently the only manufacturer to offer a three-year/36,000-mile warranty with an optional powertrain warranty in a 50-state-emissions-legal supercharger kit. For the cost, those benefits make this kit a no-brainer.

We proved that just about anyone with basic mechanical skills can take a new 5.0 and mod it with a Roush blower.

Baseline Testing the Stock 5.0

Our first order of business was to head to the only local track (to your author) that was open in the dead of winter, State Capitol Raceway in Baton Rouge, Louisana. We loaded up and headed South for a test and tune session with our barely-broken-in stock 5.0. The weather was sunny and cool with temperatures in the low 60s and a DA (density altitude or corrected altitude) of around 800 feet, according to our Crew Chief Pro and Altronics PerformAire PC trailer-mounted weather station.

We made several test passes with various launching techniques and had a best of 12.83 at 110.8 on the factory 18-inch wheels and tires, with a 2.02 60-foot time. Launching around 1,500 rpm, we saw very little wheel spin, even on street radials. We bolted on a set of Bogart D10 race wheels wrapped in Mickey Thompson 325/50R15 drag radials on the back and M&H 185/55R17 up front. This netted us a staggering 68 pounds in overall weight loss, so we knew there would be a noticeable gain. After several passes, the car consistently showed us 12.7s with a best of 12.73 at 110 with a 2.00 60-foot. Just from drag wheels and tires alone, we dropped a tenth.

To solidify the track results, we decided to dyno-test the car for baseline horsepower numbers at Stang-Hi Performance, also in Baton Rouge. Using its Dynojet, the stock-trim Coyote made 368 rwhp and 348 lb-ft of torque. We were impressed with the results from a completely factory Mustang, but we were starving for more power and quicker track times.

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After the Roush Phase Two supercharger kit arrived, it was time to give rise to the Steed. We chose not to pay a performance shop to install it. Instead, we saved about $1,500 in installation costs and gained the experience of doing it ourselves. We wanted to create a truly DIY scenario that just about any Mustang enthusiast could relate to and even duplicate. My husband, JD, along with fellow 5.0 racing buddy, Adam Yeager, began the one-day, relatively painless supercharger install in our home garage.

Phase One

In this installment, we provide you with the first-hand basic installation sequence, along with any notes that may make the job easier. Literally anyone can install this kit if you have basic mechanical know-how.

Following Roush's meticulously detailed instructions, we disconnected the battery cables and removed the PCM to overnight it to Roush with the supplied FedEx overnight box. Roush recalibrated the PCM with its 50-state-legal calibration, and the PCM was back in our hands in less than 36 hours—impressive service. Don't forget to fill out and mail in the card to maintain the Roush warranty on your vehicle along with your PCM.

One thing we noticed immediately upon thumbing through the approximately 80-page instruction manual was a glaring statement at the top of every page: Premium Fuel Only. You can bet Roush's number-one priority is keeping all conditions as safe as possible in order to warranty these kits.

We also should mention the sticker that clearly states on the PCM to not recalibrate, in bold letters, after Roush has calibrated it and sent it back. If you flash the PCM with another tune, Roush will no longer honor its warranty, and we can't blame them for that. As you can expect, there is a difference between a CARB/emission-legal tune and a custom tune that is designed only to meet the standards of making more power.

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