Conor Mills | Freelance Automotive and Travel Journalist

Freelance Automotive and Travel Journalist

Feature: Aston’s desert stormer

Posted by Admin On September - 14 - 2014

It’s one of the toughest tests imaginable for Aston Martin’s new Rapide, as we team up with the firm to put it through its paces in some of the world’s most extreme terrain.

Modern cars have to be tough. And that doesn’t mean simply withstanding the rough and tumble of Britain’s potholed roads.

Before a new model hits forecourts, manufacturers need to be sure it can cope with the most extreme conditions the world can throw at it. So, where better to put this to the test than the scorching hot, hostile climes of the Middle Eastern state of Kuwait? And what better car to follow than Aston Martin’s Rapide, as engineers put the brand new four-door through its paces.

South of Iraq and north of Saudi Arabia, Kuwait is one of the hottest places on earth, with temperatures regularly exceeding 50 degrees Celsius in the summer. The constant, scorching heat is ideal for uncovering design and engineering flaws in new cars, and we were about to find out how. Our brief visit was only scheduled to last 24 hours. But by 7am, the temperature was already approaching 40 deg C!

Even more surprising was the volume of traffic on the roads – it was as heavy as during a mid-week rush hour in the UK. And rock-bottom fuel costs in the Middle East meant most of the other vehicles were 4x4s.

We arrived at our base camp at 8am and were introduced to the Aston team conducting the assessments. After a brief outline of what the group had been doing in the desert, we were given our itinerary, followed by a history of the Rapide’s life so far.

Starting out in June 2007, the car was born and tested as a computer-aided design. Two rough versions were then built and assessed: one for thermal and cooling, and one for powertrain and dynamics.

Aston reached the first serious testing stage in autumn 2008, and with the help of five mules, began the full development phase and started looking at all aspects of the car’s set-up and performance.

This was followed by the verification stage – which is where we came in. For the Rapide, Aston built 14 verification prototypes (VPs), with each used to check more specific elements of the car, such as heating, ventilation and air-con (or HVAC), dampers and brake noise.

VPs are also driven around test tracks all over the world to make sure that, dynamically, the car is just right. One specific thing is tested on each vehicle at any one time, but each prototype is used to check around six elements in its life.

The last stage for the car is called ‘tooling tryout’. These are the very final versions, with every component fine-tuned, and could be considered as models ready for sale.

The Rapide we would be testing was reaching the end of its life cycle as a verification prototype, and we’d be analysing its heating and ventilation systems, as well as the air-con unit. This was particularly important, as the sports saloon is the first Aston to get front and rear air-con, so there would be a far greater emphasis placed on the system.

The engineers began by giving us a 360-degree tour of the Rapide. Apart from some buttons that didn’t work and a few rough edges, the only noticeable difference between the mule and the production version was a 90-channel data logger fitted in the boot.

This was attached to a complex network of wires running throughout the car. In turn, each of these was connected to sensors measuring either temperature, pressure or voltage in the cabin or engine – meaning that readings could be taken at any point, anywhere in the car.

Chief vehicle engineer Simon Barnes had the thankless task of being our nominated driver for the day. He invited us to climb aboard, and then he gave an overview of the tests he’d carried out so far and talked us through how each one was designed to emulate an aspect of everyday driving.

All that was left to do was start the engine and begin our day as a hot-weather tester. We started with a 100-mile early morning loop.

With temperatures already reaching 45 deg C, this is a great way to get heat into the car quickly while covering a large distance. It was also the perfect opportunity to assess the general reliability and performance.

Another important part of the morning run was to check the alternator’s recharging capabilities.

We switched on all of the Rapide’s battery-powered appliances (air-con, radio, cooled seats, daytime running lights, etc), and the 200-amp alternator was working to its limit to make sure it could recharge the battery effectively under the test conditions.

With the hottest part of the day approaching and temperatures now exceeding 50 deg C, the next test involved leaving the car parked outside in the intense midday sun for an hour – typical of an everyday lunch stop.

Sixty minutes later, the team measured what’s called the solar load placed on the car during the break using a device on the roof. To give an idea of how hot the sun in the Middle East can get, a typical solar test in a factory is usually limited to 1,000kW/h, as values higher than this rarely occur in habitable climates.

But after returning from lunch, the laptop was reading a peak value of 1,100kW/h! Following a quick drive to measure how long the car’s air-con unit took to return the cabin to a comfortable temperature, the next test was all about city driving.

The stop-start nature of this type of motoring means the vehicle isn’t allowed to rest, and as a result is always heating up. It’s one of the most important and relevant checks a new car must complete.

The final part of the day was spent doing something very different. After we were happy with the Rapide’s electronics and its ability to deal with common everyday tasks in the extreme heat, the last check focused on the engine and brakes. This is called the traffic light test and comprises a series of five controlled 0-60-0mph acceleration and brake checks. It was a great way to look at the durability of the car’s engine and stoppers.

The day ended by driving back to Aston Martin’s flagship Kuwaiti dealership where the car was checked over, cleaned and prepared for the next round of testing. As we were given a final rundown of what the team had found out, all the day’s results and data were downloaded on to a laptop for further and future analysis.

Even though our behind-the-scenes trip was brief, it gave us a fascinating insight into the seriously demanding process of hot-weather testing.

That we had the chance to experience this in the luxurious, leather-bound cockpit of next year’s most eagerly anticipated supercar was a bonus!

Publication: Auto Express

Online version: Click here

Original print version: Part 1, Part 2, Part 3