A first look at the Audi TT RS plus

Audi is taking aim at the new Porsche Boxster and its yet-to-be-revealed sister model, the upcoming second-generation Cayman, with a spectacular 174-mph version of the TT RS, pictured here officially for the first time.

Called the TT RS plus, the powered-up coupe and roadster pairing is set to join what is shaping up as a formidable display of new Audi models--including the third-generation A3 and the RS4 Avant--at the Geneva motor show in early March.

The centerpiece of the new range-topping TT is a tuned version of Audi's turbocharged 2.5-liter, five-cylinder direct-injection gasoline engine as used by the go-fast TT RS, the RS3 Sportback and the limited-production A1 quattro.

Mounted transversely over the front wheels in a showcase-lacquered, carbon-fiber-trimmed engine bay unique to the new car, the four-valve-per-cylinder engine delivers 20 hp and 11 lb-ft of torque more than the standard tune. The result is 355 hp and 343 lb-ft of torque, 44 hp and 78 lb-ft more than the new Boxster S's naturally aspirated 3.4-liter, horizontally opposed six-cylinder.

Among the changes brought to the compact powerplant, known internally under the code name EA855, is a revised intake manifold and added turbocharger boost pressure. Together they provide the 3,196-pound TT RS plus coupe with a power-to-weight ratio of 244 hp/ton, with the 3,334-pound TT RS plus roadster coming in at 235 hp/ton.

Engineers at Audi's quattro division headquarters based in Neckarsulm, Germany, also gave the TT RS plus an exhaust-system flap that opens during generous application of the throttle for added aural effect.

As with the TT RS, drive is channeled through a standard six-speed manual gearbox to all four wheels via a Haldex-style multiplate clutch. A seven-speed dual-clutch S-tronic gearbox featuring a launch-control function that matches revs to prevailing grip levels for optimal getaways is available as an option.

So equipped, Audi says the TT RS plus coupe will storm from standstill to 62 mph in just 4.1 seconds, with the slightly heavier roadster taking 4.2 seconds. In manual form, the cars require an additional 0.2 second, respectively, according to Ingolstadt's official performance figures.

Top speed in both cases is limited to 174 mph, up 19 mph over the standard TT RS, which is limited to 155 mph. The gain in performance is achieved without any dramatic effect on fuel consumption, which Audi puts at 27.6 mpg for the coupe and 27.4 mpg for the roadster.

By comparison, the new mid-engine/rear-wheel-drive Boxster S, which is also set to make its world premiere at the Geneva motor show, reaches 62 mph in a claimed 5.0 seconds, tops out at 169 mph and returns a combined 29.0 mpg.

Along with the TT RS plus's engine upgrade is a revised version of the standard TT RS's firm-riding MacPherson strut (front) and multilink (rear) chassis, complete with sinister-looking black-and-red painted 19-inch alloy wheels shod with 255/35 tires all round. Buyers can specify an optional adaptive damping system that uses magnetically actuated dampers to vary the firmness as part of Audi's Drive Select system. The standard brake package is retained, with four-piston calipers and cross-drilled steel discs up front.

A series of exterior styling changes help distinguish the TT RS plus. Together with the new wheel and tire package, they include a new grille that uses a high-gloss anthracite-colored, diamond-pattern plastic insert and a matte-aluminum-look plastic frame. The exterior mirrors were altered, with new carbon-fiber-reinforced plastic housings, while the sizeable tailpipes at the rear get black oval trims. As a finishing touch, there's also a redesigned fixed wing for added downforce and stability at speed.

Set to head into production in April, the TT RS plus is the latest product of Audi's increasingly active quattro division, which now oversees a growing lineup of performance models, including the company's new RS4 Avant. European sales begin in May.

Details relating to North American sales have yet to be revealed. In Germany, the TT RS is priced at €60,650 ($80,580) for the coupe and €63,500 ($84,367) for the roadster, with the optional seven-speed dual-clutch S-tronic gearbox adding €2,150 ($2,856) in each case.

By Greg Kable