|
BMW’s CSF is light, fast and cheaper
|
01/04/2007
|
| |
The exhaust treatment system for the new BMW X5 3.0d combines a metallic catalytic converter and silicon carbide diesel particulate filter within a single housing and is a standard fit, writes Roger Bishop.
Engineered by Boysen, the distance between the catalyst and the filter is a mere 10mm – just enough space to accommodate the temperature sensor.
To optimise efficiency and ensure rapid light-off, the assembly is located close to the engine. When required, soot particles are burnt off by a controlled increase in the exhaust temperature by post-injection of fuel.
According to Rainer Diez, head of technical development at Boysen, the catalytic soot filter – or CSF – does more than save space and weight. “It also uses less material and requires fewer production and assembly steps, making it cheaper than a two-part system,” he said.
Boysen also saved weight and cost in the X5’s silencing system “The original design included a middle silencer, but in the end we succeeded in integrating its function into the rear silencer,” said Diez.
Both CSF and silencer system for the diesel engine (as well as the manifold and close-coupled cat for the three-litre petrol version) are manufactured at Boysen Gaffney plant in South Carolina. However, the engineering was done in Germany.
|
| |
Author
Roger Bishop
|
| |
| Email this article |
| |
|
|
|
|