The Holden Monaro 427C was an Australian built and designed GT style race car based on the Holden Monaro CV8 road car. The car ran in the Procar Australia-run Australian Nations Cup Championship and at the short-lived Bathurst 24 Hour race at the famous Mount Panorama Circuit in Bathurst.
Concept In 2002 Holden Motorsport was looking at running a Holden Monaro in the first ever Bathurst 24 Hour endurance race against the likes of the Lamborghini Diablo GTR, Ferrari 360 N-GT, Chrysler Viper ACR and Porsche 911 GT3 that were regulars in the Nations Cup Championship. After the Holden Racing Team reportedly turned down the job of building the Monaro, Garry Rogers Motorsport accepted the task of building the car as well as running it. The Monaro was originally intended to be debuted in 2003, but after the go ahead had been given for the Bathurst 24 Hour to be run in November 2002, the car's build and development time shortened to just 9 months.
The Monaros ran a GRM developed version of the Chevrolet Corvette C5-R's 7.0 litre (427 cui) motor which had taken numerous class wins in the 24 Hours of Le Mans and the American Le Mans Series as well as outlasting the Prototypes to take overall victory in the 2001 24 Hours of Daytona. However, while the racing Corvette's used a purpose-built racing version of the LS1 V8 engine (dubbed the LS1.R), the GRM 427 cui engines were instead based on the road-going Chevrolet Corvette Z06's upgraded (but still 5.7L) LS6 engine block (the internals of the Monaro engines did include a number of the C5-R's "off the shelf" GM racing parts in order to bring them up to the full 7.0L size and internally GRM still refer to them as their C5-R engines). GRM's engines were built by the team's engine builders Mike Excel, who also designed a special inlet manifold for the engine, and Jeff Maxwell.
The aero kit (front and rear wings) on the Monaro was based on the similar aero package used on the Holden VX Commodore that ran in V8 Supercars (the Monaro road car was a 2-door coupé version of the VX Commodore), though the rear wing was larger than a V8 Supercar's and to conform to GT regulations had to be lower in height than the cars roof line. GRM and Holden Motorsport also used a lot of their V8 Supercar components on the Monaro to make it a stronger race car. The car ran on 18 x 11 inch wheels at the front and 18 x 13 inch wheels at the rear while the wheels were supplied by OZ Wheels. The cars were also fitted with a 6-speed sequential gearbox made by Melbourne-based racing gearbox supplier Peter Holinger.
The Nations Cup Monaro was controversial thanks to its 7.0 litre V8 as the road going Monaro was only equipped with the smaller, 5.7 litre Gen III (LS1) V8. Many of the categories fans and a number of the other competitors felt that the car should have been using the 5.7L engine, as all other cars in the GT based Nations Cup Championship were required to use production based engines of the same capacity as their road going versions. However, Procar (founded and funded by long time Dick Johnson Racing's multi-millionaire sponsor Ross Palmer of Palmer Tube Mills fame) wanted a local manufacturer competing for wins in the championship's top category and gave Holden special permission to use the 7.0 litre engine in the Monaro in order to better compete with higher powered 6.0 litre, V12 Lamborghini and the 8.0 litre, V10 Viper. Having the 7 litre engines without there also being a road car equivalent saw a misconception almost from the cars beginning that the Monaros were actually running the full Le Mans C5-R race engines which were claimed to give them an unfair advantage. Unfortunately, a large part of the fans' confusion was because Nations Cup and Bathurst 24 Hour TV broadcaster Channel 7 promoted the Monaros as having a "Corvette based engine", but it was never explained by either Channel 7 or Holden that the engines were actually upgraded versions from the Z06 road car and not the same 7 litre motors used in the Corvette race cars.
Holden did later announce the HRT 427 road car which was unveiled at the 2002 Sydney Motor Show and it was widely believed that this would be the road going version of the 427C race car. The HRT 427 (HRT for the Holden Racing Team, although technically they had little or nothing to do with the project other than the use of the name) was based on a modified Holden Monaro bodyshell and, among other things, it featured a 7.0-Litre V8 engine developed by long time Sprintcar and NASCAR Stock Car engine builder John Sidney of John Sidney Racing (JSR) in Melbourne. However, due to the high cost specifications, the business case for full production failed since Holden could not built the 427 in such limited quantities for the original asking price of A$215,000. In all, only two road and four racing versions were ever built.HRT427 at ultimatecarpage.com
The first car was built in mid-2002 and was given a shakedown run by GRM's V8 Supercars lead driver Garth Tander at the Calder Park Raceway in Melbourne before it made its first public appearance when Holden Motorsport bought track time at the 2002 Bob Jane T-Marts 1000 V8 Supercar race at Bathurst in order to promote the Bathurst 24 Hour to be run later in the year (much to the chagrin of V8 Supercars management who didn't know until moments before the Monaro hit the track that the time would be used to promote a "rival Bathurst race"). On track at Bathurst the yellow Monaro (nicknamed the "Nuclear banana") wore Tander's usual #34 rather than the #427 which it would wear until the end of 2004. Prior to the 24 Hour race, GRM also completed limited testing with its three of its four nominated drivers at the tight Winton Motor Raceway in rural Victoria (Cameron McConville wasn't brought into the team until about a week before the race and his first drives of the car were actually in qualifying for the 2002 Bathurst 24 Hour).
2002 Bathurst 24 Hour In its race debut at the 2002 Bathurst 24 Hour, the #427 Monaro was driven by Tander and fellow V8 Supercar drivers Steven Richards, Nathan Pretty and Cameron McConville. McConville's first drive of the car was actually during qualifying where he qualified the car in second place on the grid. As expected, GRM's regular driver Garth Tander started the race and using the power of the 7.0 litre engine was able to take the lead almost from the start. Although Holden cars had a strong reputation at Bathurst and the similar engined Corvette C5-R's had scored numerous class wins in GT endurance racing, the Monaro was seen as too new pre-race and wasn't really considered a chance of winning or even finishing its debut race despite the relatively low quality of the field with only 3 or 4 of the 36 entrants considered a true chance for outright honours. While the 7.0 L engine with its off the shelf GM racing parts was mostly a known quantity, many felt that the Monaro's other racing components would have suspect reliability. Although as veteran driver, twice Bathurst 1000 winner and winner of the inaugural Bathurst 12 Hour Allan Grice pointed out, the Monaro shared a lot of parts with V8 Supercars which had over 10 years of proven Bathurst race history, while fellow (7 time) Bathurst 1000 winner Jim Richards, who is also the father of Monaro driver Steven Richards, labelled the Monaro "A better V8 Supercar".
Holden had expected that the Monaro would be given a rev limit of 6,700 by Procar as that was generally what the Le Mans Corvette's used. However, when GRM got to Bathurst they were informed that the Monaros had to be set for 5,700 rpm, a full 1,000 below expected. As driver Nathan Pretty would later point out, the 7.0L V8s had shown in testing that they didn't make their true power until well after 6,000 rpm so in racing the drivers never got to exploit the real power of the engines, though the torque levels of the engines did often compensate for that loss of power, especially at Bathurst. It was the lower rpm limit that saw a drop-off in power, and a higher overall weight, which was put down as the reason the Monaros didn't match the V8 Supercar times on Mount Panorama.
After Tander used the torque of the 7.0 litre V8 to take the lead from the John Bowe driven Ferrari 360 at the start, the car suffered an early flat tyre which dropped it to second behind the Cirtek Motorsport Porsche 996 GT3 RS of David Brabham, while the high revving, 3.6 litre V8 Ferrari had already suffered the first of two engine failures early on and was out of contention. Then, just a few hours into the race after re-taking the lead from the Porsche, the entire fuel cell of the Monaro needed to be replaced, dropping the car 13 laps behind. The team overcame the fuel cell problem as well as the car becoming jammed between gears just before sunrise after Nathan Pretty was hit by the BMW 318i of Debbie Chapman in The Chase, which also caused damage to the driver's side door. The Monaro spun and stalled, jamming the gearbox, forcing Pretty to get out and rock the car back and forth to clear the problem, a task made difficult by the Monaro's Sequential transmission and its weight. By the 18-hour mark (10 AM Sunday morning), the Monaro had clawed its way back to second place, only three laps behind the leading Porsche. Then after a trouble free run, the Porsche broke a half-shaft with Brabham at the wheel, causing the car to pit for four laps. Sensationally, the Monaro pitted at the same time as the Porsche to replace rear suspension bolts that had broken away from the chassis. The GRM crew won the pit race and the Monaro was able to return to the track and re-take the lead for good with just over 4 hours remaining. When the Porsche returned to the track, Allan Grice, told to drive as fast as possible, hit the wall on the top of the mountain while attempting to lap the Mosler MT900R driven by Mark Pashley which broke the Porsche's rear suspension and took it out of contention. Upon its return to the track Darren Palmer put the car into the wall at Griffin's Bend with no steering, a legacy of the Grice crash.
The Monaro ran in the lead for the last four hours to win the race by 24 laps from the British entered Mosler MT900R of Martin Short. In the race, Tander's fastest race lap of 2:14.3267 was actually quicker than Brad Jones' pole time of 2:15.0742 and quicker than McConville's qualifying time of 2:16.8792 (in the warm up session prior to the race, Tander had actually recorded a 2:13.6871 which was the fastest time of the session by some 6.3313 seconds). With the demise of the Bathurst 24 Hour and Nations Cup after 2003 and 2004 respectively, Tander's 2002 fastest race lap time stands as the Nations Cup class record lap for Mount Panorama.
2003 Nations Cup It was then widely expected that regular GRM V8 Supercar driver Tander would drive the car in the 2003 Australian Nations Cup Championship, and Tander himself stated that he would like to race the car. However, with input from Holden Motorsport it was former AUSCAR and part-time V8 Supercar driver Nathan Pretty who was given the drive instead. Pretty went on to score numerous race wins in the series, including round wins at Symmons Plains and Winton, but would finish third in the eight round championship behind the Lamborghini of Paul Stokell and John Bowe in a Ferrari.
Following the Monaro's dominant Bathurst 24 Hour win, Procar enforced the use of air restrictors on Monaros (as they did other competitors in the name of parity) which they would use for the rest of their racing life. The FIA approved 30mm air restrictors brought power back down from an alleged to around , though torque would remain the same at around .