DETROIT – Toyota Motor Sales U.S.A. Inc.’s Lexus luxury division says the new performance version of its IS sport sedan, the IS-F, will make more than 400 hp when it goes on sale in the U.S. in early 2008.

Lexus unveils the IS-F, as well the LF-A sports car concept, today at the 2007 North American International Auto Show here. The auto maker first unveiled the LF-A concept at the 2005 Detroit auto show and says this latest version is close to production ready.

“Lexus has long been perceived as the maker of mainstream luxury vehicles. But the unveiling of the IS-F and LF-A not only changes this perception, it also introduces a new Lexus marque,” Bob Carter, Lexus group vice president and general manager, says of the new “F” branding.

“The ‘F’ shared by both vehicles is the signature for a new high-performance marque conceived by an engineering team that dared to turn their dream of ‘a Lexus like no other’ into a reality,” Carter says.

The “F” designation originated internally two decades ago with the birth of the Lexus brand in a project dubbed “Circle-F,” with the “F” standing for “flagship,” Lexus says. Today, the “F” designation represents “a special vehicle program within Lexus that falls outside the normal engineering and development process,” the auto maker says.

The IS-F, which Carter says is not intended to be a competitor to other performance sport sedans but rather a sport sedan made “in the Lexus way,” was developed primarily at the Fuji Speedway and Higashi-Fuji Technical Center in Japan.

Based on the existing rear-wheel-drive V-6-powered IS 250 and 350 models, the IS-F features a 5L V-8 with a 2-stage intake system expected to produce more than 400 hp and more than 350 lb.-ft. (475 Nm) of torque.

Other performance add-ons include engine-oil and transmission-fluid coolers and a cylinder head-scavenging oil pump; the latter for high G-force driving, Lexus says.

The engine is mated to what Lexus calls the world’s first 8-speed direct sport-shift automatic transmission, which uses a new torque-converter that continually locks up second through eighth gears for “direct, crisp gear changes,” Lexus says.

With the transmission in Drive mode, Lexus says the IS-F goes from 0-60 mph (97 km/h) in 4.9 seconds.

A manual mode can be activated via paddle shifters behind the steering wheel, which allow for up-shifts within a tenth of a second, Lexus claims. Throttle-blipping downshifts are governed to match engine and vehicle speed.

Lexus-specified Brembo brakes are used to handle the vehicle’s high-speed potential, with 14.2-in. perforated discs in front and 13.6-in. rear discs. The front discs have 6-piston calipers, while the rear discs use 2-piston calipers. For the first time on a production model, the calipers will bear the Lexus name. Wheels are custom 19-in. alloys.

Lexus modified the IS suspension for the IS-F, lowering it by more than 0.5 ins. (1.3 cm) vs. the base IS and more than 1 in. (2.5 cm) compared with the IS riding on 18-in. wheels.

A new 3-mode version of the Lexus Vehicle Dynamics Integrated Management system for electronic stability control debuts in the IS-F, with a new Sport mode that allows a driver to push the performance envelope farther before the stability system intervenes.

VDIM also can be turned off with the new 3-mode system.

The IS-F remains faithful to the look of the IS, but Lexus has made slight changes by adding quad tailpipes, a larger grille and a rear spoiler.

The IS-F’s interior sports aluminized composite trim; “F” logo on the steering wheel and rear-center console; and specially shaped and trimmed seats, which better grip drivers, Lexus says.

Meanwhile, the new LF-A improves on the concept shown in 2005 with an updated version of Lexus’ L-Finesse design language.

Carter says Lexus will monitor consumer reaction to the new LF-A.

“This latest concept is much closer to a vehicle that we would bring to market,” he says.

The LF-A still sports a V-10 engine making more than 500 hp, with a top speed of 200 mph (322 km/h).

cschweinsberg@wardsauto.com