Thunder From Down Under: Holden Stuffs LS7 Into HSV W427 Sedan

The muscle car wars may just be in their revived infancy here in the United States, but they’re alive and kicking in Australia. Unveiled at the Melbourne Auto Show, the latest weapon from Holden’s HSV tuning wing - the W427 - stuffs the Corvette Z06’s LS7 into one mean Commodore sedan.

Taking its name from the motor’s displacement, HSV squeezes the 427 cubic-inch (7.0-liter) small-block V-8 underhood, coupled to a six-speed manual transmission. Although the motor makes 505 horsepower in the Z06, it’s been mildly de-tuned for the sedan, producing 496 horsepower and 470 pound-feet of torque - still plenty for a modern muscle sedan.

(Click through for more on the W427 sedan, including a gallery and a release from Holden)

Helping control that power are new springs (lowering the car 20 mm), revisions to the stability program, and new six-piston front disc calipers - twice the size of those on lesser Holden models. Looks aren’t forgotten either; The W427 sports a new front fascia, a carbon fiber rear spoiler, 20-inch alloy wheels and a vibrant red leather trimmed interior.

W427 production starts this fall, but don’t expect this to arrive Stateside as another Pontiac G8 variant. HSV intends to keep production extremely limited, meaning even Australian enthusiasts may have difficulty wrangling one from the factory. What say you - should Pontiac drop the LS7 into the G8 for North America, or should the General leave the high-end performance sedan segment to the LS9-powered CTS-V? Let us know in the comments section.

HOLDEN RELEASE

Holden Special Vehicles unveil seven litre Supercar the W427
Holden Special Vehicles today unveiled a seven litre program at the Melbourne Motor Show, the last instalment of the company s 20th anniversary celebrations.

The car to be known in its final development stages as the W427 is finished in the same Panorama Silver paint scheme as the original Group A SS VL Commodore, released at the Melbourne Motor Show of 1988, exactly 20 years ago.

HSV Managing Director, Scott Grant, said the W427 was a tribute to how far the company has come in just twenty years.

“To be able to produce a vehicle of these proportions is truly remarkable,” Scott Grant said.

“The W427 will be quite possibly the fastest road registrable Supercar ever produced in Australia and among the quickest anywhere around the world,” he said.

While power output figures are still to be confirmed, the W427 is likely to produce in excess of 370kW of power and 640NM of torque.

“It will also be one of the safest cars HSV has ever put on the road,” Scott Grant said.

“A new six piston front braking system will provide a 50% increase in pad area, while the W427 also receives a revised ESP calibration, six air bags, improved handling and new Magnetic Ride Control settings.”

The W427 receives a bimodal active exhaust system to improve noise quality and back pressure management.

Styling and design highlights include an all new front fascia, a three piece carbon fibre rear spoiler, 20 inch machined faced alloy wheel, unique exhaust tips and red leather interior.

Scott Grant said HSV would be introducing a unique customer relations program to accompany the launch of the new vehicle.

“The W427 will only be produced in limited numbers and we want to reflect that exclusivity in how we connect with our Supercar customers,” Scott Grant said.

“This program will see the LS7 engine being fitted at Clayton, along with the dry sump system and a range of other engineering features. We are looking at opportunities to allow owners to visit HSV and view the unique manufacturing process that goes into building this car.”

The W427 will go into production in the middle of the year and will be available for sale in dealerships in the third quarter of 2008.

“Make no mistake, while the specifications of the car unveiled on the stand today at the Motorshow may change slightly between now and when production begins, this car is destined to make as big an impact as the original Walkinshaw twenty years ago.”

W427 key highlights

Exterior
All new Front Fascia exclusive to W427
All new three piece rear spoiler in carbon fibre
All new 20 inch wheel

Interior
HSV performance seats in full red hot trim with W427 logo, steering wheel, gear shifter and console lid in full red hot leather

Powertrain
7.0 Litre, LS7 Engine with HSV specific calibration
370kW @ 6500 rpm
640Nm @ 5000 rpm
Over radiator style cold air induction system with high flow air filter
Dry sump lubrication system with 2 stage pump
Hand fabricated aluminium oil reservoir, with internal baffles for high G loading
Front mount, 13 row engine oil cooler
Ceramic coated, high flow four into one extractors
High flow catalytic converters and exhaust system (3 into 2 ¾ )
Active bi-modal rear mufflers for exhaust back pressure management to improve noise quality
High strength limited slip differential
New high strength six speed manual gear box (TR6060)
GMPT LS7 Clutch with new actuator and pedal assembly for high clamp loads

Suspension
New springs, 30% stiffer than GTS
Revised ride height 20mm lower than GTS
New stiffer rear suspension bushing
All new MRC calibration

Brakes
New 6 piston front braking system (50% increase in pad area)
Strap drive, 2 piece floating front rotors (380 x 35mm compared to 365 x32mm one piece on GTS)
High friction pad material