Frank H. Cicerale
May 1, 2008

Step By Step

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Mmfp_0805_roush_01_z 2008_roush_427R_mustang BurnoutMmfp_0805_roush_16_z 2008_roush_427R_mustang Rear_view
For 2008, the Roush 427R is available with an automatic transmission. Our Dark Candy Apple Red tester was fully optioned and checked in at $51,085. A base 427R will set you back $43,689.
Mmfp_0805_roush_03_z 2008_roush_427R_mustang Engine
The Roushcharged Three-Valve sports an intercooled supercharger kit with a performance-tuned ECM. In addition to having 435 hp, the 4.6 makes 400 lb-ft of torque.
Mmfp_0805_roush_14z 2008_roush_427R_mustang Driving_shotMmfp_0805_roush_02_z 2008_roush_427R_mustang Front_viewMmfp_0805_roush_04_z 2008_roush_427R_mustang InteriorMmfp_0805_roush_13_z 2008_roush_427R_mustang Seats
Our tester had the optional Roush Sport leather buckets priced at $1,725.
Mmfp_0805_roush_05_z 2008_roush_427R_mustang Console
A carbon-fiber trim overlay is part of the optional interior trim kit.

With enough cash in hand, just about anyone can buy a fast Mustang. You can do so right from the local Ford dealer, and once behind the wheel of your 400-500hp stallion, you can tear up the streets, road course, or hit the strip and run deep into the 12s or the 11s. The coveted Shelby GT500, along with the Saleen and Roush supercharged models, will get you there with style and grace. But there's always been a rub with fast, factory, late-model Mustangs: If you wanted the big-daddy engine, you had to get a manual transmission.

That was true until recently when MM&FF wrapped its arms around a popular Roush 427R Mustang, a serious snake that Roush executives tell us is selling like hotcakes. Our tester was fashioned in Ford's new Dark Candy Apple Red Metallic and sported a center stripe, bold 427 badging that flows into a slashing side stripe, and 18-inch wheels. Under the hood lurked a supercharged Three-Valve belching out an impressive 435 hp--backed by an automatic transmission! Yes, an automatic, the 5R55S five-speed to be exact. That the 427R had an auto tranny was of great interest to us, since we've never tested a new supercharged Mustang with anything other than a stick.

"The 427R was designed as more of an entry-level price package for a vehicle equipped with a modified powertrain," says John Clark, communications and motorsports manager at Roush. "This car doesn't typically have all the included features of the Stage 3, such as the side molding and rear fascia. Options on the 427R, such as the four-piston brakes, are standard on the Stage 3. Perhaps the biggest difference is in the suspension and wheels. The 427R has cast wheels and a suspension tuned to the heavier wheel/tire package. The Stage 3 has lighter forged wheels, and the suspension is tuned for that setup. Consumers will notice a number of small but important differences between the two vehicles."

Performance purists and road racers will insist on a clutch and a gear jammer because there's nothing like pulling off the perfect powershift and/or selecting the proper gear for coming out of a corner. Furthermore, stick guys take pride in being an integral part of the acceleration process, not to mention that modern Mustangs have not been known for having performance-oriented automatics (remember the AOD?). Stick versions have always been two-to-five tenths quicker in the quarter.

While true in years past, the '05-up 5R55S five-speed automatic is far and above its predecessors. It is rather strong and benefits from a steep 3.25:1 low gear and close ratios in Second and Third as well, thus providing crisp acceleration and loads of fun for the driver, not to mention amazing simplicity for those not wanting to bang gears or driveline parts.

Strip Savvy
Not ones to dilly-dally, we locked into "Drive" and hustled to the dragstrip. Could the 427R automatic hang with the Roush Mustangs previously tested by MM&FF? In the past, we've run 12.50s in a Stage 3 and 11.90s in the pricey Drag Pak.

On a cool day at Raceway Park, we put the 427R against the clocks and laid down a series of 12.40s at 107-108 mph, our best being a 12.44 at 108. This came after burning out, staging shallow, and by releasing the Roush with a smooth yet aggressive application of power.

Looking for more, we bolted on a set of drag radials, powerbraked to 1,800 rpm, and mashed the gas--hard. The "R" scooted from the line with no spin (1.76 60-foot time). It then pressed us firmly in the seat until we crossed the stripe 12.32 seconds later at 109.36 mph. Going fast was as easy as deactivating the traction control, canceling Overdrive, and then flooring the electronic throttle. Impressed? We were.

While 12.30s are quicker than most other stock Mustangs, we still wanted more. The weather report showed high pressure and cooler temps were coming, so a second trip to E-town was planned. Using the same sticky drag radials and breathing colder air, we managed a quicker 12.20, again at 109 mph to end the day. The decrease in e.t. was representative of the cooler air, but due to a stiff head wind, the speed didn't pick up. The strong wind killed about 2 mph and a few thousandths of e.t.