Don Roy
April 1, 2007
Photos By: Brad Bowling

William Johnston's 2005 Roush Mustang
Cranking out customized Mustangs has become pretty easy to do these days. There are a good assortment of body kits, lots of go-fast parts and, apparently, plenty of people to buy up the results. Still, there are some names that have been associated with the Mustang industry for a long time and ROUSH Performance is one of those. The 2005 Screaming Yellow beauty you see in these pages got a warming over even before it was delivered into William Johnson's possession.

Now, William is ... ahhh, there's no kind way to put this ... a car nut. By his own count, since he took possession of his first car in 1956, he has had 289 cars and trucks pass over his driveway. William had just taken delivery of a 2007 Cadillac Escalade on the weekend before we spoke with him. That addition put the current driveway occupancy up to nine vehicles, including a BMW M5, Corvette Z06, Ford GT, assorted others and this Roush Mustang. As it happens, he'd ordered the Mustang as a companion to the Ford GT and both cars share the same color scheme - Screaming Yellow with black stripes.

Stage 1
At the time, though, Roush was still only building Stage 1 cars, so that is what was delivered. William was quite taken with the styling of the car, but he knew that some more work was going to be needed. "I don't care to drive anything with less than 400 horsepower," he told us. In fact, that same preference had previously led William to discover Fastlane Motorsports, in Benson, NC. At the time, he'd been looking for someone to 'top up' the power in a newly acquired F250 Harley Davidson pickup truck. That work had been successfully completed at Fastlane so, when it came time to look after his most recent vehicle, he had no qualms about calling Melvin Skinner again.

As delivered in February of 2005, this Mustang had received a full Roush body kit along with the optional leather interior upgrades. Although the Roush wheel package for the car was on hold, William wasn't prepared to wait any longer and had it shipped "as is." The wheels would follow in due course. Beyond this, the car was a blank canvas when the Skinner family got their hands on it. An overall plan was developed that included a power adder, but first there was suspension and chassis work to accomplish.

The car was dropped using a set of Steeda Sport springs and a Steeda rear sway bar replaced the original. The lower rear control arms were replaced with Steeda billet versions to help with traction tasks that were looming on the horizon. Their strut tower brace was also called up for duty. Since William enjoys 'spirited' driving, but is long past the days of street antics, this was enough suspension work for the time being. When they arrived and were fitted, the Roush 18 x 10-inch forged aluminum wheels, wrapped with 275/40-18 BF Goodrich g-Force KD tires were up to any road task that William had in mind. He did join the club at Virginia International Raceway and goes there with the Ford GT whenever the his need for speed does get hopping.

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Stage 3
The power adder that William and Fastlane had decided on was an intercooled Vortech V-2 SQ S-Trim supercharger. This would safely increase the rear wheel output of the Roush to well over the 400 horsepower level. Exactly where remained to be seen, but given Caleb Skinner's tuning skills, it would be a good jump. Now, any supercharger addition can't be safely handled without upgrading a number of other components. Along with the gear-driven compressor, Vortech provides a number of fuel delivery and management components. These start with a set of 39 lb/hr fuel injectors, as used on the 2003-04 SVT Cobra. At the other end of the car goes a 255 lph Vortech fuel pump. A low restriction air filter and 98mm MAF (mass air flow) sensor with DiabloSport MAFia mass air interface led the air charge into the supercharger itself.

To enable higher boost levels, Vortech provides an integrated air-to-water, dual pass configuration charge cooler. Compressing air naturally heats it up and reduces its density which limits the amount of oxygen available to support combustion of fuel. Effectively cooling the intake charge means that the air is denser, more oxygen is present and more fuel can be burned. The pleasant outcome of all that, of course, is more power and an ever-widening grin.

To optimize the finished installation, Vortech also provides a DiabloSport Predator hand-held programmer to adjust the factory engine control computer processor for any needed fuel and timing adjustments. The is Caleb Skinner's area and when his work was done, the dyno spit out the results - 480 RWHP @ 6300 rpm and 421 RWTQ @ 5000 rpm. It looks like William won't have any trouble passing those logging trucks on the back roads around North Carolina.

Stage More
A few interior enhancements went into this Roush as well. A Steeda Tri-Ax short shifter sits atop the TR-3650 transmission, helping make sure that hitting third gear under pressure is not a problem. Information delivery is supplemented by a brace of Auto Meter carbon fiber gauges, including boost pressure, oil pressure and voltage data. An XM satellite radio was also added to make sure that ear candy was always close at hand.

In the end, William is fully satisfied with both the Roush Mustang and the supplemental work done by Fastlane Motorsports. To add a final touch, appropriate to the bona fides of the car, our boys updated the Roush level badge at the rear of the car to Stage 4. Were Jack to get his hands on this screamer, we're sure that he would approve.

William Johnson's 2005 Roush Mustang

Ford 4.6-liter, 3-valve V-8

Engine Modifications
Ford 2004 Cobra 39 lb/hr fuel injectors; Vortech S-Trim supercharger, dual 255 lph fuel pumps, intercooler; Diablo Predator tuning by Fastlane Motorsports

Steeda Tri-Ax short throw shifter

Steeda strut tower brace

Roush body kit, including front and rear fascia, side skirts and rear wing, quarter window louvers, rear wing

Auto Meter carbon fiber gauges, including boost pressure, oil pressure, voltage; XM satellite radio

Steeda billet lower control arms, Sport lowering springs, rear sway bar

Wheels And Tires
Roush 18 x 10" forged aluminum wheels; BF Goodrich 275/40-18 g-Force T/A KD tires

480 RWHP, 421 RWTQ