Heat wrap and downpipes with cats

[Grinder34]

I have a catted downpipe--is wrapping the cat:
a) Something to avoid
b) Doesnt matter
c) Do it!

I know cats only work when hot, so I'd think keeping the heat in the cat would help emissions. I also dont like the idea of exposed metal--kind of defeats the purpose of having the exhaust wrapped! But I do hear internet wisdom about wrapping the cat causing it to get too hot.

Any advice is appreciated!

 

[Vermont]

Cats generate heat. Not sure how much. I will say proper wrap is good, improper wrap causes moisture to be trapped against the metal promoting corrosion

What about the cats burning up? I had heard this can happen when they are heated up to much, so I am wondering along with Grinder if wrapping would cause problems that way...

 

[IGOTASTi]

I would like to know about this. I see people wrap headers all the time, but I would highly doubt wrapping the cat would be good.

 

[Grinder34]

I did a bit of searching which led me to Wikipedia: http://en.wikipedia.org/wiki/Catalytic_converter#Temperature_sensors

It appears the cat should be "safe" to above 1600F. At least on my EGT probe, temps [almost?] never get that high even at the head, so post-turbo the EGTs should be significantly lower. That is, unless the catalytic converter is performing an exothermic reaction that could put the EGTs back into a dangerous region.

I'll continue to search.

 

[HolyCrapItsFast]

To much heat inside a cat can evaporate the platinum film that is deposited on the ceramic substrate rendering it useless. Beyond that I don't think it is a good idea to wrap the cat. It has an optimum operating temperature and if you wrap it you risk exceeding that temperature.

 

[Vermont]

To much heat inside a cat can evaporate the platinum film that is deposited on the ceramic substrate rendering it useless. Beyond that I don't think it is a good idea to wrap the cat. It has an optimum operating temperature and if you wrap it you risk exceeding that temperature.

Would he be able to wrap the pipe up-until the cat and still be fine? or just leave it un-wrapped?