Consumer Guide recently spent some time behind the wheel of Roush's 427R (left) and Stage 3 Mustangs (right).

Affordable speed is much sought-after by car enthusiasts, and Ford's Mustang "pony car" has been a strong seller for four decades for just that reason. But for some owners, too much of a good thing is not enough, and the quest for more takes them beyond the realm of the rational--not to mention beyond the scope of affordable. For those folks, a Roush-tuned Stage 3 or 427R Mustang might just be the ticket.

The venerable Mustang has been a top choice for tuners over the years. Examples of customized Mustangs abound, and there are several companies that dedicate themselves to producing tuned thoroughbreds. Some of these companies are aftermarket, and some have factory connections. Roush Performance, which is affiliated with Jack Roush Racing and Ford Motor Company, is one of the more well-known Mustang builders and offers several versions of the Mustang.

Roush Performance Products was founded in 1995 by Jack Roush. It's a subsidiary of Roush Industries, which was founded in 1976 and originally called Jack Roush Performance Engineering. The former Ford engineer and professional drag racer founded Roush Racing in 1988, and built a name for himself in the world of NASCAR. When Roush Performance Products was founded in 1995, Roush partnered with Ford to build modified Mustangs and F-150 pickup trucks.

The Transformation

Consumer Guide had the opportunity to sample Roush Performance's Stage 3 and 427R Mustangs. We were able to drive both cars on the track and over the rolling hills of east-central Wisconsin.

The Stage 3 and 427R are both based on the stock Mustang GT. Both use a supercharged version of the Mustang's 4.6-liter V8. Other enhanced underhood bits include new high-performance intake manifolds, an intercooler and heavy-duty radiator, a performance-oriented air induction system, and a reprogrammed electronic control module (ECM). The Stage 3 is boosted to the tune of 430 horsepower, while the 427R has 435 horsepower. Both cars send 400 lb-ft of torque to the rear axle. The stock GT's 5-speed manual or 5-speed automatic transmissions are available.

Both models tested use a supercharged version of Mustang GT's 4.6-liter V8.

The other major upgrade to Stage 3 and 427R Mustangs is the suspension. Each car gets upgraded struts up front and shocks in the rear, with beefed-up springs and sway bars at both ends. This setup is intended to turn a Roush Mustang into a much better handling car than its stock GT sibling. Other go-fast goodies include 18-inch wheels with high-performance tires, a freer-flowing exhaust, and heavier-duty brakes. Styling is modified, too: Stage 3s get a seven-piece body kit that includes a hood scoop, changed front and rear fascias, a front chin spoiler, different rocker panels, and a rear wing. 427Rs get just the front fascia, hood scoop, front chin spoiler, and rear wing. Both cars get lower valance fog lamps. 427Rs roll on heavier cast chrome wheels, as opposed to the forged chrome wheels on the Stage 3.

In addition to the bodywork, both packages include a number of minor exterior and interior styling tweaks. On top of the basics, several optional trim bits are available, including a carbon-fiber dashboard kit and a short-throw shifter for manual transmission cars. The interior doesn't differ much from a stock Mustang GT, and creature comforts such as leather seats and air conditioning are available (and appreciated). A fully-loaded Stage 3 can run $53,607 before the destination fee and taxes. A 427R with every option box checked will set you back $51,925, again before taxes. That's a lot for a Mustang--now you're entering Corvette territory. Can a modified Mustang compete with Chevy's factory hot-rod?

The Roush cars certainly talk the talk, with an engine note that would sound right at home at any muscle-car cruise night in America. The question is, can they walk the walk?

Track Time

On the track, the Stage 3 and 427R both feel plenty fast. The supercharger provides linear power delivery even at low engine speeds, and though we did no formal performance testing, it feels like the Roush duo has enough guts to play with other American muscle such as the Corvette or Dodge Viper. The same can't be said of the stock GT. The short-throw shifter takes some getting used to, and that's a shame, since it can slow down drivers who aren't familiar with it. Once acclimated, however, the quick shifting helps the driver get back on the throttle without wasting much time. Neither model felt quicker than the other.

A fully-loaded Stage 3 (left) can run $53,607. A loaded 427R (right) will set you back $51,925.

Handling is far superior to that of a stock Mustang, and there isn't much drama, although one gets the sense that if the car is pushed hard enough, it may not be all that forgiving. The steering feel wasn't as sharp as that of a base Corvette, but it was good enough to instill confidence that the driver won't end up in the weeds. Both cars felt planted and solid on the track, although with that much torque on tap, one needs to apply the throttle judiciously when exiting a corner, lest the rear end break loose.

On the Road

One might think that a car like this wouldn't be civilized enough for around-town driving, but the 427R held its own on public roads. The 427R attacked the twisty Wisconsin rural roads with plenty of gusto, but it also felt larger and heavier than it really is. The ride was stiff, but it was never punishing, nor did broken pavement torture occupants. The exhaust note that was so exhilarating on the track quickly gets old; making a booming noise that suggested that the car was unhappy loafing along at low RPM. This is a car that wants to play, and it's not shy about letting you know it. It handles competently, but it's not razor-sharp. The brakes on our tester were strong, but they were outfitted with track-ready brake pads that induced a high-pitched squeal in around-town driving.

It's fun to tap into the 427R's reserves of available power--and to hear that muscle-car exhaust note at full song--but when the road turns curvy, there isn't much joy in its handling. Hustling through corners isn't exactly a taxing chore, but it's clear that this car is more at home on the straightaways. Curiously, the 427R did handle appreciably better during track duty. Perhaps the suspension setup favors track time over backroad rambling?

The bottom line with either Roush Mustang is that they're fast, fun, and they offer the same level of usable practicality as a stock Mustang (which is to say, not much, but at least it's something). But they don't handle as well as a Corvette, aren't as brutally fast as a Viper, and they probably don't have the "wow" factor of the recently introduced Dodge Challenger SRT8. However, Mustang owners can be fiercely loyal, and the factory partnership that Roush has with Ford gives it a leg up on other aftermarket tuners. For the deep-pocketed Blue Oval buyer who isn't satisfied with his "run of the mill" GT, Roush provides an intriguing alternative.