Pretty regularly, we can test cars without even going outdoors. Our Milford facility has several test laboratories in which we do simulations. The other day I snapped this shot of a new CTS during a Dynamometer test in our lab. (Apologies for how dark this photo is ... )
Dynos can be used for several things. In our world, driveline dynos are used for measuring horsepower and torque. This full chassis dyno enables the car to operate fully, yet in a stationary manner via platforms underneath all four wheels that hold the car into place. The fan you see in front of the car blows air into the intake to replicate the airflow that would happen if the car were moving. Those are acoustic tiles all over the walls of the room to enable precise measurements of noise, while the test operators sit outside the room in a booth, with computers monitoring the data. This test is measuring vibration and potential disturbances over various speed ranges.
This is a key test, even at this very late point in the development cycle. While much of a car’s characteristics are highly tuned early on, there can be small variations once all the production parts are seemingly finalized and all working together. These could result in potential detriments in the sound quality, or a slightly different “feel” as the car goes down the road. So we use these dyno tests to measure the consistency of every sound and vibration – not only the quantity of sound and vibration, but also little things such as the exact frequency ranges of these potential disturbances. We’ll even take videos from an underground bay to watch the driveline and chassis as it goes through the test, and also listen to sound recordings on headphones, more on that soon.
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Comments
With the new CTS to debut very soon, will any findings from the recent durability and dyno affect the production of the '08 models? Or will the benefit of those tests only be seen in later models?
Posted by: Marc | August 15, 2007 5:14 PM
Can you perhaps post the sound? I'm interested in how the DI sounds compared to the standard 3-6.
Posted by: Scott | August 16, 2007 3:43 AM
Yes, sometimes the findings can result in pretty immediate fine-tuning that can see production quickly. Other times it is a more long-term effect, depending on the type of change needed.
Posted by: editor | August 17, 2007 7:50 AM