November 4, 2003

Lexus shows V8-powered IS 430 prototype

Las Vegas, Nevada – Lexus unveiled a one-off example of its IS 300 luxury sport sedan powered by a 4.3 litre V8 engine from a Lexus GS 430 on Monday. Lexus commissioned Rod Millen Special Vehicles (RMSV) to build the car. The resulting “IS 430” was completed last week at Millen’s shops in Huntington Beach, California.

“We wanted to explore the performance possibilities of the IS 300,” said Lexus Group Vice President and General Manager Denny Clements. “The marriage of our 4.3 litre V8 with the sporty IS 300 creates a classic muscle car.”

IS 430 project

IS 430 project
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The V8 engine was paired with a Getrag 6-speed manual transmission and lightweight flywheel, which drive the rear wheels through a stronger limited slip differential and GS 430 driveline components.

TEIN springs and 16-way electronically adjustable shock absorbers work with the original IS 300 front suspension in addition to selected GS 430 rear suspension components, which help ensure durability against the higher torque of the 4.3-litre V8. Large, sticky Michelin Sport Cup tires on 18-inch Speed Star SSR alloy wheels put the power to the ground.

A similar approach was taken with the cooling system and brakes. A GS 430 radiator was fitted to provide ample cooling for the high-output engine. Large Brembo brakes with vented, cross-drilled rotors and four-piston aluminum calipers are there to arrest the newfound acceleration and speed of the IS 430.

“The standard IS 300 is a robust and well balanced sport sedan, so we thought it would respond well to the additional power of the Lexus V8 engine,” said Rod Millen, president of RSMV. “With a package of complementary modifications, it has exceeded our expectations.”

“Fitting the 4.3-litre V8 and six-speed manual transmission to the IS 300 was fairly straightforward,” said Millen. “The larger challenge was to develop an electronic interface that would allow the V8 engine to work with the manual transmission and IS 300 body – something it was never designed to do.”

Lexus also wanted to discover the potential of what might be termed a “next generation” in-vehicle entertainment system. Lexus turned to its premium audio systems partner, Mark Levinson.
The result is a 20-speaker/24-channel, 720-watt audio/video system using a proprietary DVD video player and removable 6.5-inch wide-screen video display.

To complete the package, Chip Foose from Foose Design was employed to give the IS 430 a more aggressive yet functional appearance. Foose used subtle upgrades including a Rhys Millen Racing front lip spoiler and side skirts with a black over red exterior color scheme that emphasizes the wedge profile of the tightly drawn IS body. A mesh grille and gray headlamp treatment is used up front, and the taillights and rear badging are modified for a simpler look at the rear. Dual exhaust tailpipes help improve performance.

The Lexus IS 430 is a one-off vehicle. There are no plans for a production version.

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