It has been shown within the catalyst industry that the emission performance with higher cell density technology and therefore with higher specific geometric area is improved. The focus of this study was to compare the overall performance of high cell density catalysts, up to 1600cpsi, using a MY 2001 production vehicle with a 4.7ltr.V8 engine.
The substrates were configured to be on the edge of the design capability. The goal was to develop cost optimized systems with similar emission and back pressure performance, which meet physical and production requirements.
This paper will present the results of a preliminary computer simulation study and the final emission testing of a production vehicle.
For the pre-evaluation a numerical simulation model was used to compare the light-off performance of different substrate designs in the cold start portion of the FTP test cycle.
Four sets of converters were aged for 72 hours at 1025°C on an engine dynamometer stand, which is equivalent to 50k mile road driving condition. The emission performance of the catalysts was tested according the FTP75 driving cycle in close coupled and toe board position. In addition emission testing, back pressure tests before and after aging were also carried out.