As released at the 2002 Sydney Motor Show, the HRT 427 show car was a closed-circuit racer featuring a 7-litre V8 racing engine based on the Le Mans-winning C5R Corvette powerplant. Over the past 15 years the HSV brand has been built on motorsport success and creating exhilarating road cars that contain serious levels of motorsport derived DNA. This race track concept, which simmered within both HSV and Holden, has boiled over with the two companies collaborating and creatinh the breathtaking HRT 427.

427 In Detail

Racing heritage features under the bonnet with a V8 engine that shares its 427 cubic inch (7.0 litre) capacity with the legendary big block Chev. Based on a Corvette C5R race engine, it’s been hand built by HRT technicians, incorporating their own unique piston and CNC cylinder head design. This very special powerplant feeds through eight individual throttle bodies with carbon fibre trumpets.

‘HRT 427 is the ideal showcase for potential new HSV production technology,’ said project head, Brad Dunstan, TWR (Aust)’s Manager of Advanced Engineering. ‘We’ve taken every performance and handling idea we have in the book and incorporated them into the HRT 427. One of the developments for this car that we hope to get into future HSV production is the double ‘A’ arm front suspension.’ The race-style system consists of a set of beautifully crafted aluminium A arms, complete with fully adjustable dampers, which take the place of the Coupe’s standard strut front suspension.

Everywhere you look there’s seriously high spec performance mechanicals. A heavy-duty 900Nm clutch transmits the engine’s prodigious output to a special T56 six-speed manual gearbox. Hand built for HSV by Tremec (makers of the standard T56), it features the same lower ratios as the Corvette Z06 and includes triple synchros to reduce shift effort.

Braking is via a race-bred AP Racing six piston system including competition style full floating and grooved rotors. Inside, there’s a half roll-cage and Sparco Pro 2000 driving seats (as used in the British Touring Car Championship) to hold the driver securely in place behind an HRT style steering wheel and Motec instrument panel.

A strict weight reduction program, instigated to further enhance performance, sees it tip the scales at just 3472 lbs (1575kg) or 200 lbs (100kg) less than HSV’s GTS Coupé. Exotic materials abound, including a carbon fibre bonnet, saving 31 lobs (14kgs), manufactured using a revolutionary Australian process called ‘Quickstep’ and magnesium for the HRT inspired 18-inch wheels and the unique differential housing. Audio and air conditioning systems are deleted, as are the rear seats which are replaced with carbon fibre panels to cover the lightweight dry cell battery.

Green Light to Production

Clearly, the world supercar club had welcomed a new member. The car’s surprise first appearance at the Sydney motor show attracted much attention – from the media, from HRT fans, and, importantly, from some 80 customers who paid HSV Retailers deposits on the car.

At that time there were no specific pricing, specification levels, or production numbers, just a desire from HSV to showcase its ability, along with racing partner HRT, to develop a truly world class performance car.

This is the biggest and most complex project we will have undertaken. We are doing it as it is a wonderful advertisement for HSV being a world leader in high performance specialty cars, added HSV Managing Director John Crennan.

Pricing will be approximately $215,000 dollars. Production will commence later this year.

A Stillborn

June 16th 2003 – Holden Special Vehicles today announced that it would not go ahead with production of the HRT427 super car.

Fifty firm orders had been placed for the vehicle, with an unexpectedly high proportion to be for road use. HSV’s desire to build the car to the highest level of safety, engineering integrity and excellence to meet the expected asking price of $215,000 was not achievable at the (restricted) 50 vehicle build level.

To achieve a road car level of specification would have required significantly higher investment levels and resultant higher recommended retail price. Further, HSV was not prepared to build more than 50 units as this would seriously degrade the exclusivity of the very exciting 427 model, nor was HSV prepared to lower the specifications from that of the original show car intent, which may have diluted the integrity of the concept.

HSV expressed great disappointment in not bringing the 427 model to market, as the prototype vehicles that were completed had achieved their engineering objectives and vehicle intent. HSV’s General Manager, Chris Payne, confirmed – The unfortunate and disappointing decision was one purely of business case economics that could not be made viable given our price and customer studies.

‘The decision is particularly disappointing as the prototypes already demonstrate the engineering prowess of HSV to develop and build high performance supercars that can compete with the best marques in the world’ he added.

Story by Holden Special Vehicles & Supercars.net