joshua22se said:
what is that -iam a newby!dont know haha
This should help (found elsewhere on the net)
Here's a ceramic core catalytic converter. These are typically done in 400-500 cell per inch count. I can't remember what this particular photo is from, as I never named it for it's part number. Suffice it to say, it's above 400cpi:
Ceramic catalytic converters are the mainstay of the industry. They are the least expensive to produce, but retail still isn't 'cheap'...as many of you are aware.
Next up are the metal matrix catalytic converters. Instead of using a ceramic core, these use a metal core. They're more expensive to produce, but the cell count can be made lower...which increases the flow and the performance of the vehicle. They also benefit from an increase in the ability to withstand shock, vibration and physical impact much better then a ceramic core catatlytic. Rich running, which will melt and break-up a ceramic core, won't negatively effect the FLOW of a metal catalytic, though it may effect it's ability to clean the emissions. The fact that the matrix won't break up and block flow, however, is a huge benefit to race and performance vehicles, which is why metal matrix cats are gaining in popularity. Many OEM's are using them in stock applications as well.
In metal catalytic converters you'll find a NUMBER of different cell counts, everything from 150 to 400cpi. Cell count won't effect the ability to pass emmissions, but the amount of precious metals used WILL. Thus, one 350cpi cat may not pass a sniffer test, while someone elses 200cpi will. The important thing to inquire about is what the maximum engine size the catalytic converter has been dipped for. A 4.0L catalytic, for instance, will have no problem passing on a properly running vehicle with a 4.0L engine or smaller.
To give you an idea of the increased flow capacity, here is a 300cpi metal matrix core...if you look carefully you can see that the passages are larger then the 400+cpi core above.
Here is our 200cpi metal matrix core. Sorry the angle sucks, but you can see that the passages are much larger then the two catalytic converters pictured above
Hopefully this clears up some confustion, if you've got questions, post 'em up and I'll be happy to answer em."