CALIFORNIA CITY, CALIF. -- At the height of the day, the skid pad in the middle of Kia/Hyundai's 17.4-square kilometre proving ground gets so hot, the act of breathing is enough to make just about anyone perspire. At 2 p.m. on the day I visited, the mercury was pushing 47 C. But the searing heat is the very reason the proving ground sits in the Mojave Desert, just 200 kilometres from the hottie of the lot, Death Valley.
Hot-weather testing ensures the interior materials and paints will withstand a 40 C day without fading, cracking or melting. Some of the weathering test rigs not only track the sun, but increase its heat by using 10 mirrors to focus it directly onto the test piece. This speeds up the testing process. Three months in this environment is about the same as three years under normal conditions.
The unspoken attraction to California City is testing can be conducted most of the year without interruption.
Ringing the environmental weathering chambers is a series of roads -- sand and gravel thoroughfares used to find out how the abrasive grit affects the suspension and other under-car components. It could be something as simple as the grit migrating to the shock-absorber seal that spells disaster.
The engineers also conduct grit-ingestion tests in much the same way as they test for snow ingestion during winter testing, much of which takes place in northern Quebec.
On another section of the proving ground, there's a road that's littered with rocks about the size of the tip of one's thumb. Hooning down this road not only reveals what happens when a stone gets lodged in the suspension or, worse, the brakes, it is used to find out where the body is most susceptible to stone chipping -- it is this testing that determines where the protective plastic pieces are fitted to the production car.
Another of the road sections replicates just about every surface the car will ever face, regardless of where it is driven. There's the age-old Belgium Block test -- it shakes the living daylights out of the car while torturing the driver at the same time. The vehicle's body is then driven down a road that has a hump on the left and a hollow on the right and vice versa for several hundred metres. It torques the body to the point where any interior squeaks and rustles become full-on moans and groans.
The worst test, however, is a cinder-block section of pavement that is rougher than any road I have encountered -- perhaps the lone exception being the "highway" that links Moscow to St. Petersburg. As with the proving ground's block road, the 700-km M10 highway that links the Baltic to the Russian capital is best described as one enormous pothole with intermittent sections of pavement. If something is going to break, it will do so here, and in dramatic fashion.
Ditto for the test that sees cars driven through a 100-millimetre pothole -- the noise the car makes when it hits the pothole at speed is excruciating.
The central skid pad is used to test for many things, the most important being the subject's propensity for rolling over during an emergency manoeuvre. As they say, this is a safe place to do unsafe things.
With a real driver at the wheel and outriggers stretching from either side of the vehicle, it is accelerated down the vast asphalt expanse until it reaches a predetermined speed. Pushing a button then prompts robotics mounted to the steering wheel to begin conducting the actual test. First, the robot steers to the right and then, as if a truck tire has exploded or another obstacle presents itself unexpectedly, it whips the steering wheel to the left to avoid a potential collision.
The robotics ensure the steering movement can be repeated again and again with exacting accuracy. In this instance, when the car is turned in one direction and then steered rapidly in the opposite, it unloads the back end, which causes the car to oversteer as the body heels over -- this puts it at risk of rolling, which is the leading cause of death in car crashes.
If the test vehicle's response is marginal, the suspension, roll centre and any number of other components are tweaked and the test repeated until it passes. This is an important test for any car, but it is particularly important for a vehicle with a higher centre of gravity.
Ringing the entire facility is a 10-km oval that's banked at 12 degrees so there is virtually no need to steer or touch the brakes when heading into the 180-degree corner at 200 km/h. This is where the mule's high-speed stability is verified.
Finally, there is a twisty handling track. Here, experienced drivers conduct evaluations on everything from handling, ride quality and steering response to the perceived feel and feedback the driver receives from the car. While instrumented testing delivers detailed empirical data, it does not necessarily reveal how a real driver will perceive things.
This is the final phase before the car embarks on an accelerated testing regimen that piles on hundreds of thousands of kilometres over a very short time frame. It is all used to ensure the vehicle works over its expected life.
-- Postmedia Network Inc. 2013