Liberating the Beast Within: Lexus Unleashes V8-Powered IS 430 Project

Lexus unveiled a one-off example today of its IS 300 luxury sport sedan powered by a 4.3-liter V8 engine from a Lexus GS 430. Seeking to demonstrate the potential of the IS 300, 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, Calif.

'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-liter V8 with the sporty IS 300 creates a classic muscle car.' The potent 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.

Total Performance Approach:

The concept direction from Lexus required that handling be matched to the high-powered V8 while maintaining reasonable ride comfort and noise levels. 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-liter 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.' Although not a simple conversion, the V8 and 6-speed fit well within the compact IS 300 body structure. Curb weight is slightly higher than the standard IS, some of which is due to larger/stronger components needed to deal with the increased performance and some from the new audio/video system.

'Fitting the 4.3-liter 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.'

RMSV's engineering team met the challenge with expertise developed through years of successful racing and building special vehicles for military and automotive clients. They focused on designing the electronics interface while simultaneously working through the mechanical conversion and enhancements. Numerous parts were specifically fabricated for the IS 430 including stainless steel exhaust headers and dual exhaust system, transmission adaptor, engine and transmission mounts, air intake system, wire harnesses and fluid connectors.

'Next Generation' Entertainment System:

Pushing the IS 300 performance envelope was not limited to vehicle dynamics. Lexus also wanted to discover the potential of what might be termed a 'next generation' in-vehicle entertainment system. Lexus naturally turned to its premium audio systems partner, Mark Levinsonâ, whose system engineers were eager to gain experience with their advanced system development work and receive feedback from users in the field.

The goals for the experimental system were the introduction of a discrete multi-channel 7.1 surround sound experience suitable for automotive use, complete system integration of audio and video, and advancement of sonic performance beyond previous OEM premium systems. The result of their vision 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. This prototype Mark Levinsonâ system is well suited to the expanded performance of the IS 430.

Functional Aggression:

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 not only improve performance, but also help advertise the potent 4.3-liter V8 engine.

by Lexus

Toyota's luxury division unveiled its newest sport-luxury compact sedan in 2001, the Lexus IS 300. Sharing its engine with the larger GS 300, the IS was built with rear-wheel drive and carried a 3.0-liter inline 6-cylinder engine that achieved 215 horsepower. The engine operated with VVT-i. During its first season, only a five-speed automatic transmission was offered, but it did incorporate Formula One-inspired E-Shift gear selection on the steering wheel. The wedge-shaped IS body had a semi-fastback roofline and was sharp-edged in design. It was called a 'condensed high-performance stance' by Lexus. A choice of either 16 or 17 inch wheels could be mounted on the IS 300 and front-side airbags were installed along with antilock braking and traction control. Available on the vehicle was a limited-slip differential. Inspired by sport watched, a chronograph-style instrument panel was installed in the vehicle. The IS 300 was originally designed for the European market, and is promised to give 'compelling challenge' to European sport sedans.

Though smaller than the BMW, the Lexus IS300 carried a fairly tight rear seat, though it had a high level of comfort. In Japan, the Lexus IS300 was sold as the Toyota Altezza. Introduced in 1999, the IS 300 went on sale in June of 2000. Shortly afterward, it appeared as the CART Championship pace car. Along with the IS 300 SportCross, a five-speed manual-transmission version was debuted. The sedan and the little-known SportCross was somewhat publicized by two racing entries in the 2001 Grand-Am Cup North American Street Stock Series. Competitive immediately, the IS scored its first pole position in its fourth race and first race win in the fifth round at Virginia International Raceway.

In March 2003, the IS SportDesign was introduced, basically, a cosmetic package equipped with a special grille, tailpipe along with other touches. Sharing its in-line six-cylinder engine with the Supra, the Lexus IS 300 came with rear-wheel drive and an interior that was more sport than luxury. 215 horsepower was produced with the six along with 218 lb-ft of torque that used variable valve timing to broaden its torque curve. The IS 300 also had a two-stage induction system along with a two-way bymass muffler that enhanced breathing and lower noise. Excellent handling was provided by a double wishbone suspension.

When desired, the SportCross and the automatic transmission sedan featured E-Shift steering wheel-mounted shift buttons for finger-tip control over gear shifts. Basically a wagon/crossover version with the same dimensions as the sedan, the IS 300 featured a rear tailgate, a split fold-down rear seatback and fold-down front passenger seatbacks that allowed it to carry either long or odd-shaped items. A rear power outlet and a seatback table were also located in the folding passenger seat.

Wind noise was lowered due to a low 0.29 coefficient of drag, while the interior was quieted with sound-dampening asphalt sheets in the roof. Optional on sedans was a real spoiler, while the SportCross featured a unique spoiler as standard equipment. The IS300 had drilled aluminum pedals with rubber pads, supportive height-adjustable seats and stainless steel doorsill scuff plates. 17-inch wheels, low-profile performance-tread tires, auto-dimming side and rearview mirrors, a high-power audio system with both a cassette player and six-disc in-dash CD changer with eight speakers, and High-Intensity Discharge headlights were all standard features.

Optional on the IS300 was eight-way power driver's and passenger seats, heated front seats and a power moonroof. The interior could be outfitted with an optional leather/Alcantara trim package or a full leather-trimmed interior in either ivory or black.

The SportCross offered the Vehicle Stability Control system as an option. This was also optional on the automatic sedan. This feature was helpful in controlling traction while cornering on slippery or dry road surfaces by utilizing throttle intervention. To help limit rear-wheel slip on acceleration the VSC supplements the standard full-range traction control. Brake Assist and Electronic Brake force Distribution was featured on the four-sensor, four-channel anti-lock brake system. To determine if the driver is attempting emergency braking, brake assist is designed to figure this out, along with if the driver has not stepped firmly enough on the brake pedal to engage the ABS. The system supplements the braking power applied until pedal pressure is released.

Pretensioners and height-adjustable anchors are incorporated on the front seatbelts in the Lexus IS 300 to help avoid the forces to the upper torso in a serious frontal collision. The SRS, Supplemental Restraint Systems included dual front airbags, side curtain airbags for the driver and front passenger, and front seat-mounted side airbags. A personal security feature is the speed-sensitive and shift-linked automatic door lock/unlock system.

An optional feature on the Lexus IS 300 was the Lexus Navigation System which used a DVD for map storage. All on one disc, the DVD contains all of the U.S. and the major cities in Canada. High-speed route calculation, multi-route calculation, route preview, a dual-map screen mode and simplified highway junction graphics are functions of the Navigation System. Deployed from the dashboard, the System is easily hidden when not in use. The remote controls for the system are hidden in the center console between the front seats. A dashboard storage compartment with a spring-loaded retractable lid is featured on models not equipped with the Navigation System.

For 2004 all Lexus IS models added a standard maintenance indicator light along with automatic power door locks. In October 2005, the second generation of IS models were introduced, the IS250 and the IS350.

by Jessican Donaldson