Not Ranked
probably too late to add anything of relevance, but as an ex auto engineer i thought i'd chime in with some previous knowledge.
In the tune of "oils aint oils sol", cats are the same, the precious metals used on the carrier or substrate are expensive, Palladium, Rhodium or platinum, so manufacturers only use what will get them over the ADR 37/01 emissions averaged over a decreed drive cycle, it is submitted by the manufacturer for compliance, not tested by 3rd party, but evidence is required. this test may not be the same test as conducted with ICV's.
Most of todays engines are considered Lean Burn Technology so the cats require less substrate than say 5 years ago.
My suggestion would be to look at cats from an earlier model known to be high in nasties, like the older Holden and Ford cats, keep away from the imported vehicles as lean burn was implimented OS long before Aus-land. or use a diesel cat without the particle / soot catcher.
e.g VK commodore with the old 5 litre or blue motor 6 or Ford XD anything earlier than this would probably become too restrictive in flow., these cats unfortunately tend to be bigger but they needed to be.
The critical factor in today's cats is surface area of substrate that can come into contact with the gas / flow.
That's about the limit of my understanding
Cheers
|