Innovative 2 Wheeler Substrate Developments for EU5 2009-32-0102

Future tighter emission limits for 2 wheelers in Europe and worldwide will require a completely new approach in catalyst system design. In particular, the EU5 scenario, probably with the same emission limits as 4 wheelers and, for the first time, emission durability requirements, needs a new strategy to combine higher and durable conversion efficiency with the classical characteristics of 2 wheeler systems: low cost, low weight with minimum impact on exhaust system layout and engine out performances such as low fuel consumption and good power output.

This paper deals with the investigation of innovative metallic substrates keeping constant, as a first step towards the development of an EU5 system, both washcoat technology and PGM loading. In particular the effect of turbulent structures in the substrate, using PE (Perforated Foils) and LS (Longitudinal Structure) have been thoroughly investigated in testing 400cpsi PE and LS substrates.

After a brief review of past experiences with structured foils, a first test matrix was designed with the catalysts tested at constant engine load point to prevent any influence of test set up, engine characteristics and temperature profile. The three best performing substrates have been tested again using the roller bench and WMTC Cycle to compare them with the production system in order to highlight the relative efficiency improvement. An EU3 production motorbike with state of the art engine and lambda-sensor has been chosen to carry out the test.

The result of this investigation proves that high cell density metallic substrates with turbulent structures improve dramatically the conversion efficiency of the catalytic converter and form the basis for future optimization of the entire exhaust system to meet EU5 and beyond emission limits.