Hold on to your straw hats, Mustang fans. After five years of dabbling with side exhausts, suspension enhancements, and body kits, Roush Performance Parts is finally packing more horsepower into its 2 valve 4.6 Roush Mustang thanks to a Roots-style intercooled supercharger atop a new aluminum Roush intake. We’ll go straight to the numbers: 360 horsepower at 5,250 rpm, 375 ft.-lb. of torque at 3,000 rpm, 0-60 in 4.9 seconds, and the quarter-mile in 12.5 seconds at over 109 miles-per-hour.
Got your attention?
During a February 3-4 Media Drive at Firebird International Raceway in Phoenix, Roush personnel, including the straw-hatted Jack Roush himself, stressed that their goal was to build not only one of the most powerful production Mustangs but to also compete in the upper stratosphere of high-powered cars like the Z06 Corvette, BMW M3 coupe, Dodge Viper, and even the Porsche Boxster S, all of which go for more than the top-of-the-line "Premium" Stage 3 Mustang’s $48,975 retail price.
Drawing on Roush’s expertise in racing and in OEM testing and technology, Roush Performance has created an upper-end Mustang that will likely go down in history as one of the best all-around performance Mustangs ever built. Roush is also offering decontented Base and Rally Stage 3 Mustangs, which come with the factory’s dual exhaust instead of the Roush side-exiting exhausts, Brembo brakes instead of the Premium’s Alcons, and reduced badging and decals. For this article, we’ll focus on the Premium model.
Basically, if you see the wide-mouth fascia on a Roush Mustang, it’s a Stage 3. If you see both the open grille and the side-exhaust, it’s the Premium version. All are available as coupes or convertibles, with 5-speed manual or recalibrated automatic. Roush will continue to build the Stage 1 and Stage 2 Roush Mustangs, but they will not get the additional horsepower boost from the blower.
The heart and soul of the Roush Stage 3 Mustang is the Eaton Model 90, Gen 4 supercharger positioned on top of the otherwise factory-stock 4.6 2-valve long-block. Set for six pounds of boost, the supercharger pushes air through an Allied-Signal dual-core intercooler with an electric water pump and into a Roush-designed aluminum intake manifold. Other key induction components include a modified mass air flow meter, Bosch fuel injectors, BBK throttle body, and an upgraded fuel system for increased flow capacity.
To prevent front main bearing stress, Roush also engineered a 2-belt system for the front of the engine. The engine accessories continue to operate off a single belt, while the supercharger gets its own dedicated belt. Roush engineers spent considerable time and money to develop the special bracket that mounts to the front of the engine.
Which brings up another important fact about the Roush Stage 3 Mustang: Because the Roush Industries and Roush Technologies divisions of Roush are often contracted to test and certify vehicles and equipment for Ford and other manufacturers, the company has the people and equipment needed to perform durability, safety, calibration, NVH (noise, vibration, and harshness) evaluations, and other functions that are typically utilized only in the development of factory production cars. You can say that the Roush Stage 3 is as close to a Ford-produced Mustang as you can get without actually coming from Ford and no doubt the most thoroughly developed aftermarket Mustang ever.
"The car was built using a complete OEM-style product developmental cycle," said Roush Industries’ president and CEO Evan Lyall. "We have an engineering talent that rivals any of the OE manufacturers in Detroit. We intend to take our engineering and racing talent, and the Roush brand, to compete in the marketplace." Although it’s easy to assume that the Stage 3 is simply a Stage 1 or Stage 2 with a blower and larger fascia opening, that’s not the case, says Roush Performance director Ed Wayland. The Premium Stage 3 suspension, which is also an option on the Rally version, was recalibrated with a matched set of chassis components, all designed to work together to balance performance and ride quality. Included are new springs (which position the Stage 3 slightly higher than previous Roush Mustangs), Bilstein struts and shocks, and a new front stabilizer bar. Roush engineers also developed a new rear lower control arm that revises the geometry to work better with the shorter spring length. The Premium Stage 3 comes with Roush’s new 5-spoke argent wheels, sized at 18x9 front and 18x10 rear. They mount front 265/35ZR-18 and rear 295/35ZR-18 BFGoodrich Comp TA tires. Roush says the Stage 3 has achieved a .96-.98 g lateral acceleration on the Comp TAs, with even higher numbers – over 1.0g – with optional BFG tires.
To match the stopping power to the horsepower, the Premium Stage 3 Mustangs get new 14-inch front rotors with Alcon 4-piston calipers and larger 13-inch rear rotors with 2-piston PBR calipers. Preliminary repeat testing showed consistent 60-0 mph braking performance of 120 feet or less.
In addition to the wide-mouthed front fascia and the side exhaust, now with Magnaflow stainless steel mufflers and chrome tips, the Stage 3 exterior includes a Cobra hood (primarily for better supercharger clearance), new rear bumper valance panels, and a revised rear spoiler. All of the body pieces are now manufactured to mirror the same materials and processes used by Ford.
Inside, Roush has created its own front seats with European-style ergonomics, Nudo leather covers (matching for the rear seat as well), and embroidered Roush logo. The instrument cluster gets white faces with special electroluminescent backlighting and a Roush logo on the tach. Will the Stage 3 components be offered for sale individually through Roush Performance? More than likely, said Wayland, but only after enough parts are produced to build the Stage 3 Mustangs.
At Firebird, Roush brought five hastily-assembled Stage 3 Mustangs and bravely handed them to over 28 members of the automotive media, along with several of Roush’s professional race drivers, who flogged the cars on the Bondurant Driving School road course. By lunch break, Roush technicians had replaced two clutches and readjusted an exhaust system, otherwise the cars performed flawlessly. Notably, the 4.6 engines handled the supercharger boost under the extreme conditions with no problems. It is unlikely that anyone would ever submit their street Stage 3 to the type of abuse handed out by the auto press, which included Muscle Mustang & Fast Fords’ Jim Campisano and 5.0 Mustang and Super Fords’ Steve Turner. The fact that the cars survived those two is testimony enough.
On the track, the Roush Stage 3 Mustang was a joy to drive fast on the Bondurant road course. The car handles superbly without the harshness typically associated with aftermarket performance Mustangs. The Roots supercharged acceleration is as-expected – lots of torque down low that continues right up to the Roush-calibrated 5,800 redline. In fact, we heard the rev limiter kick in on numerous occasions as drivers reached the 6,050 rpm limit sooner than anticipated. The automatic-equipped Stage 3 yellow convertible felt particularly strong, as the torque-producing blower helped to overcome the usually lazy automatic performance.
Roush began accepting orders for the Stage 3 Mustang during the February 3-4 National Automotive Dealers Association show in Las Vegas. To locate one of Roush’s 225 participating Ford dealers, call 800-597-6874 or go to the new Roush Website at www.roushperformance.com where you can search for a dealer by state. Roush intends to build 750 Stage 3 Mustangs for the 2001 model year.
Job 1 is scheduled for March 16, with all Stage 3s being built assembly-line style at Roush’s new 600,000 square-foot facility in Livonia, Michigan. In fact, Roush engineers have determined that it is quicker and easier to lower the engine out of the car from underneath, install the supercharger and related components, then raise the engine back into place.
After five years of slow, safe growth as the company tested the aftermarket performance waters, Roush Performance is making a bold statement about its intentions to compete the supercar arena with its new supercharged Stage 3 Mustang.