Chrysler Group's Street and Racing Technologies team puts its distinctive SRT label on a 12th vehicle – the '07 Dodge Caliber SRT4.

The high-performance version of the auto maker's new small-car entry makes its debut today (Feb. 8) at the Chicago Auto Show.

With a turbocharged version of the auto maker's 2.4L 4-cyl. “world engine” under a bulging hood, the Caliber SRT4 will be “a hoot” to drive, says George Murphy, Chrysler senior vice president-global marketing.

The new SRT4's story can be told in numbers, specifically: 300, 125 and 85.

Its engine makes 300 hp, which is 125 hp per liter and 85 hp more than the original Neon-based Dodge SRT4.

Between 2003 and 2005, the auto maker sold more than 25,000 SRT4s, suggesting there is significant demand in the segment.

'07 Dodge Caliber SRT4

The hood features a functional scoop and two extractors.

“With 300 hp under the hood, the Dodge Caliber SRT4 will dominate the sport-compact market,” Murphy claims.

Equally impressive is its peak torque. The new engine generates an estimated 260 lb.-ft. (352 Nm) between 2,000 and 6,000 rpm.

The World Engine, product of Chrysler's joint venture with Mitsubishi Motors Corp. and Hyundai Motor Co. Ltd., makes its debut in the '07 Caliber. (See related story: GEMA Says Engine Plant is Manufacturing GEM)

But to meet the demands of SRT, the auto maker:

  • Machined its aluminum block to increase oil and water flow.
  • Used specially cast pistons and iron cylinder liners cooled by oil squirters for reliability at high revs.
  • Used tri-metal bearings for the connecting rods and crankshaft for increased durability.
  • Employed a unique oil pump/balance shaft module.

The powerplant's aluminum cylinder head also features unique high-temperature exhaust valves.

Like the base engine, the SRT version features variable timing for both intake and exhaust valves. But the camshaft and micro-alloy steel crank are the same for both engines because Chrysler claims it is “fully capable of high-horsepower loads.”

High-flow fuel injectors are unique to the new SRT4. And the whole system is managed by an all-new engine controller from Siemens AG.

The 6-speed manual Getrag GmbH & Cie KG transmission benefits from a dual-mass flywheel and a limited-slip differential capable of handling up to 300 lb.-ft. (407 Nm) of torque, which is sent to the wheels through equal-length halfshafts sourced from Chrysler Group midsize cars for greater durability.

In the right hands, this technology can push the SRT4's needle from 0 to 60 mph (97 km/h) in less than 6 seconds.

But speed means little if the driver can't stop. So the new car benefits from brake components borrowed from a premium system developed for the larger Chrysler 300, Dodge Magnum and Dodge Charger.

Painted “SRT red,” brake calipers range from 13.3 x 1.1 ins. (34.0 x 2.8 cm) in front and 11.8 x 1.4 ins. (30.2 x 1.0 cm) in the rear.

To maximize directional stability under extreme conditions, the antilock braking system and electronic stability control are specially calibrated.

Chassis upgrades from the standard '07 Caliber include MacPherson strut front suspension with new suspension knuckles and tuned dampers with revised spring rates. Unique front and rear sway bars keep body roll to a minimum during hard cornering.

But Chrysler was eager to match the car's “go” with an equal measure of “show,” says Trevor Creed, senior vice president-design.

“We wanted an aggressive, SRT-signature look,” Creed says. “For example, because the intercooler is positioned so high behind the front grille, we moved the fascia slightly forward and extended the walls of the grille. The result is a much more aggressive look than the standard Dodge Caliber.”

Further enhancing its stance is its height, which has been lowered 0.5 ins. (1.3 cm) compared with the base Caliber.

Inside, the new SRT features sport seats, a distinctive leather-wrapped steering wheel accented by a faux carbon fiber pattern and a leather shift boot with contrasting stitching.

The “alloy silver” finish on its instrument panel and shift bezel is unique to the high-performance car. Also featured are a turbocharger boost gauge and three “tunnels” that frame a tachometer, 200-mph (322-km/h) speedometer and water temperature and fuel gauges.

Another nod to driving enthusiasts are aluminum pedal pads with rubber studs, and a lift ring on the center-mounted shifter. It engages reverse.

The new SRT4 joins a lineup that, since 2002, has included the Viper-powered Dodge Ram SRT10 regular cab and Quad Cab; Chrysler Crossfire SRT6 coupe and roadster; Chrysler 300C SRT8; Dodge Magnum SRT8; Dodge Charger SRT8; Dodge Viper SRT10 convertible and coupe and Jeep Grand Cherokee SRT8.

The base Caliber began shipping last month as part of an aggressive global offensive by Dodge. (See related story: Dodge Aims High With Caliber)

The SRT4 is expected to be available as early as this summer.

emayne@wardsauto.com