The first time Brad Dunstan drove down the 'track' from Darwin to Adelaide, he was horrified to see his prized VC HDT Brock Special virtually disintegrate under the constant pounding of the corrugations in the road. That was in 1984 and Dunstan was then a bomb disposal specialist in the Royal Australian Air Force posted in Darwin and heading home on leave to visit friends and family in Melbourne.
Back then the Stuart Highway, as it's officially known, was a narrow strip of bitumen not much wider than the huge road trains that rumbled up and down its length day and night, delivering essential supplies to the tiny outposts of humanity that provide welcome relief for hot and dusty travellers. Thankfully the highway was flanked by broad verges which allowed Dunstan to pull over to avoid the shower of stones that followed as each road train thundered past.
But there was no escaping the heavily corrugated unsealed section of the highway south of the Northern Territory border in South Australia. It was there that Dunstan watched in horror as the exterior rear view mirrors on his much loved black Brock Special - the same car Peter Brock himself piloted in the one-make race for the then new VC Brocks at the Australian Grand Prix meeting at Calder Park in 1980 - drooped under the constant shaking from the corrugations to give him a perfect view of a section of the fibreglass body trim as it shook loose from the rear door and fell off.
Today when Dunstan, who is now the head of advanced engineering for TWR Australia, goes to the Northern Territory he is accompanied by a team of engineers with the express objective of putting the HSV range of vehicles through the toughest torture test in Australia and ensuring nothing fails or falls off. It's all part of the extensive testing program every HSV model is subjected to before they arrive in HSV retail outlets around the country.
On the eve of the company's 15th anniversary it was decided to lift the veil of secrecy from the testing program and let the cream of Australia's motoring media witness first hand the extent to which HSV engineers go to make sure their cars survive in some of the most inhospitable conditions on earth. The three-day trip began in Alice Springs when the media party met up with the team from HSV, which included Dunstan and a four man engineering contingent, along with Sales and Marketing Manager Mark Behr, and Penny Swan from Public Affairs.
There, waiting for them, was a selection of HSV cars - a mix of test and development mules like a Calais fitted with a 300kW engine and auto transmission, a GTS Coupé and host of brand new boxstock models such as SV300, Grange, the Maloo ute and the factory-fresh 15th Anniversary ClubSport R8.
The Stuart Highway today is nothing like the highway Dunstan experienced 18 years ago. It's now a broad expanse of bitumen stretching all the way from Port Augusta in South Australia to Darwin in the tropical far north but, while it's no longer the rough and rugged test it once was, today's 'track' presents new challenges for car makers and the engineers who design and test their cars.
Now smoother and wider, it allows drivers to push their cars to the limits. With no mandatory speed limits there is nothing stopping them from going all the way to maximum speed for hours on end. When you add high temperatures to the sustained high speeds cars are expected to endure without fail, you have the ultimate torture test - particularly for high performance cars like HSVs.
Dunstan fell in love with Darwin during the four years he was posted there with the RAAF. It's a paradise on earth for six months of the year, he says, and tolerable during the other six months when the humidity and rain are extreme. "The weather is so predictable during the winter months you can plan a barbecue five months in advance," he laughs, "and you know it won't rain and the temperature will be in the mid-30s."
It's this predictable weather that also attracts car companies to the region where they know they'll have the consistently hot weather which is perfect for testing and developing their cars.
It's not unusual for Dunstan and his crew to find themselves staying in the same town, sometimes even the same motel, as test teams from Holden, Ford or Toyota, or even from overseas companies like Porsche, Saab or any one of a number of car companies who come south to extend their testing programs during the northern hemisphere winter.
"The aim of a hot trip is to expose the vehicles to the conditions and to test all of the components," Dunstan says. "A trip can have many different people all doing different things but the aim is to see how the vehicle operates in the extreme conditions that our customers may put it through.
"That can be hot weather in Kununurra in the top of Western Australia, high humidity in Darwin or it could be cold weather up in the high country in Victoria.
"Here we have to make sure it will run at high speeds, perhaps even with the load of a caravan on it, in high temperatures without overheating or suffering any vaporisation or other hot fuelling problems.
"This is also a great opportunity for us to drive the cars, so we normally drive them up from Melbourne and take the chance to experience how they behave at the high speeds you're permitted to drive them at in the Northern Territory."
Dunstan and his team have to ensure that the vehicles they produce meet with Holden's approval before they go on sale and that means they have to undergo a full testing program that is every bit as rigorous as that used by Holden themselves. While the core vehicle on which HSV builds its special vehicles already meets the very stringent test standards set down by Holden locally, and sometimes by General Motors in America, HSV needs to ensure that the modifications they make don't have an adverse affect on the performance under any of the conditions HSV cars are likely to experience.
On this trip north Dunstan was accompanied by technician, Darren Webster, and three engineers from his HSV engineering team, each responsible for a different part of the car. Sam Davis works on the powertrain, including the engine, transmission and rear axle; Joel Stoddart specialises in the body and its effects on the cooling and airconditioning systems and the interior including the seats; and Mark Beasy is a chassis specialist whose job it is to develop the specific ride and handling package of each HSV model.
Dunstan's own automotive background is in the heating, ventilation and airconditioning areas so he's putting the GTS Coupé's cooling performance to the test. The red Coupé is put through a number of tests at various speeds and gradient loads to determine the air-temperature-to-boil (ATB) or the temperature at which the car reaches boiling point at those speeds and loads. From past testing Dunstan already knows that HSV cars will function perfectly in temperatures as high as 70 degrees C, so the mid-30s we experienced on this trip were a breeze.
Sam Davis has specialised in the powertrain area since moving to HSV from Holden six years ago. His role is to ensure that the cars deliver the enhanced performance HSV customers expect of them, and that varies depending on the model, from the luxury long wheelbase Grange through the Maloo ute and popular ClubSport to the hot 300kW GTS.
In each case he goes through a rigorous testing program on the dynamometer, back in Melbourne, to determine the optimum fuel and spark settings for full and part throttle conditions, and the transient conditions in between. He finishes with maps made up of thousands of data points which combine to make three-dimension computer plots that control the engine's operation under all conditions.
However, these maps are developed under the strictly controlled conditions of an engine test laboratory, so before he's finished he has to take the car out on the road and subject it to real life conditions. As a consequence, the laboratory results can often need refining.
"On a new program we do the initial work in Melbourne but then we get to a point where we need to look at the performance of the powertrain under hot conditions," Davis explains. "One of the major things we do is hot fuel handling which is making sure the car starts and performs properly after being switched off or left idling for a while. We do that by pulling out on the highway and accelerating at wide open throttle and the engine has to pull smoothly without any audible knock."
On this trip Davis was keen to check the calibration of the 300kW auto he's working on for later release so he's installed his calibration in a Calais test mule set up with a myriad of electronic test equipment. A heads-up display unit shows various temperatures (engine, cooling system, underbonnet), engine speed, spark advance, manifold absolute pressure, oil pressure etc, while a laptop computer was linked to a special test computer in the boot which was hooked into the car in such a way that he was able to 'tap into' the car's computer and alter any engine setting on the run. And hooked on the back was an odd looking trailer, its unusual appearance belying the fact that it cost around $250,000 when bought from General Motors in America.
The trailer, actually a towing dynamometer borrowed for the trip from Holden, was used to apply loads to the car to simulate a heavy load being towed or hills of various gradients. The load can be varied to simulate a wide variety of conditions, and the dynamometer will vary the load to adjust for a head or tail wind, or variations in the road.
Davis began his work on the Stuart Highway south of Tennant Creek the morning after we'd driven the 531 kilometres up from Alice Springs. Sitting in the passenger's seat with the laptop computer, Davis scanned the various read-outs from the instruments and listened intently for any pre-ignition that might require some change to his 'map'. With the towing dyne applying a load to the towbar of the test mule I attempted to hold a constant road speed and airflow into the engine while Davis added and took away spark advance to induce or remove detonation.
It's all part of the refinement process that HSV goes through with each new model to ensure that it not only complies with General Motors requirements but will also perform reliably in the field once it's in the hands of a customer.
Chassis engineer Mark Beasy is a relative newcomer to HSV, having recently transferred from Holden where he worked in the chassis development area. On this trip Beasy was keen to get a feel for the various HSV models as well as to work on his pet project - to quantify various aspects of the dynamic behaviour of the cars.
Mounted on the dash of the SV300 was a Pi dash of the type normally seen in a V8 Supercar. In the racecar it provides the driver with the feedback he needs to keep the car on the pace and to monitor the various systems within the car to watch for any problems that might develop. It also transmits data back to the pits where engineers can observe and analyse the car's performance. It's an essential tool for race team engineers to improve the performance of their cars and Beasy believes it can help HSV, too.
It's early days yet but he's hoping to use the system to quantify the dynamic behaviour of HSV cars which he hopes will ultimately enable him to home in on suspension settings faster and more accurately. In the SV300 Beasy had transducers fitted to each wheel to measure suspension displacement. Armed with that data along with data from an accelerometer (measuring fore-aft or lateral acceleration of the car), he can better analyse the action of each wheel in relation to the overall ride and handling of the car. It will never replace the seat-of-the-pants 'feel' of an experienced chassis engineer but it will add to his armoury.
Joel Stoddart is no stranger to the Northern Territory, having returned just weeks earlier from a fishing vacation to the South Alligator River where he managed to land a 15kg Barramundi. On this trip HSV's ever-smiling forward planner and body engineer was keen to put the air-conditioning systems through their paces. Although the airconditioning systems on HSV cars are developed by Holden, HSV's changes to the front air-dams can affect the airflow to the air-conditioning system condenser so it's important to check that there has been no adverse effect which might reduce the system's performance.
Checking air-conditioning performance is a hot and sweaty business as Stoddart demonstrated. After leaving the SV300 in the blazing sun until the interior temperature reached an unbearable 60 degrees C, Stoddart cranked the air-conditioning up to the max - recirculation and full fan at face level - and drove away while watching the temperature fall. Within the space of a minute or so the cabin temperature had fallen to a relatively comfortable 24 degrees C. Stoddart then switched the system over to outside air and checked its ability to maintain a comfortable cabin temperature while running at various highway speeds.
It might not seem very important when you know that the system developed by Holden has already had to meet those same stringent test standards and the HSV changes are unlikely to affect the result but it's all part of the commitment HSV has made to Holden and its American parents that it will meet the same challenging tests before its cars are offered for sale to the public. After three days on the 'track' (as the locals refer to the main highway) having covered more than 1500 kilometres from Alice Springs to Darwin with overnight stops at Tennant Creek and Katherine, we headed straight out to Darwin's Hidden Valley race track where Mark Skaife and Jason Bright were preparing for the V8 Supercar Championship round the following day.
After watching the HRT heroes dominate, finishing first and second in each of the three races with two wins to a rampant Skaife and a single victory to Bright (not forgetting the strong back-up performances of Greg Murphy and Todd Kelly in the TWR-prepared Kmart Commodores), it was time to head home. While it was a wrench to leave his favourite city, Dunstan could do so feeling comfortable in the knowledge that his cars had performed impeccably in the toughest conditions the Top End could throw at them. And, when he got back to Melbourne, he didn't have to refit the body kit or any other parts because, this time, nothing failed and nothing fell off along the way.
This article was first published in the HSV magazine, Excelerate. It is used here with permission.
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