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bentrod 01-15-2013 02:22 PM

headers and catalytic converter
 
newish poster, long time lurker here.

I have an LT1 and would like to run mid/long tube headers and keep my cat on my daily driver, however I've read on the internet it seems that headers (specificly long tube) and a cat can cause problems like early cat fouling.

Does anybody here run long tube headers and a cat? Can you describe your setup? The LT1 in my truck does not have the AIR system so the cat would be a one in one out.

Any other thoughts or insight about this would be appriceated.

Ironpony 01-15-2013 02:38 PM

Headers and Cat
 
The biggest problem is the heat falling out of the exhaust by the time it gets to the cat. If the cat isn't hot enough it will plug up sooner. The easy way would be to wrap the headers with a good exhaust wrap. If you look at most of the new cars coming out you will see the cats have been moved closer and closer to the exhaust ports. To the point where the cats are sometimes put in the manifold. And heat loss is the reason. Hope this helps Bill

techinspector1 01-15-2013 02:44 PM

Quote:

Originally Posted by Ironpony (Post 1635179)
The biggest problem is the heat falling out of the exhaust by the time it gets to the cat. If the cat isn't hot enough it will plug up sooner. The easy way would be to wrap the headers with a good exhaust wrap. If you look at most of the new cars coming out you will see the cats have been moved closer and closer to the exhaust ports. To the point where the cats are sometimes put in the manifold. And heat loss is the reason. Hope this helps Bill

Makes sense to me.

Ironpony 01-15-2013 02:49 PM

Headers and Cat
 
I forgot to mention to keep the cat as close to the collectors as possible too. Bill

bentrod 01-15-2013 02:55 PM

Ironpony, certainly makes sense. This sounds like the same reason the o2 sensors foul early on headers (at least the non-heated o2 sensors, like mine).

The headers I am looking at are short to mid legenth and ceramic coated. It explicitly says don't wrap them with exhaust tape because it will destory them :confused:. Maybe they mean the ceramic coating will be destoryed?

Ironpony 01-15-2013 03:03 PM

Headers and Cat
 
Then don't wrap them as destroying the coating is what will happen. You could still try to keep the cats as close to the collectors as possible though. And then what is more expensive the cats or the headers. Maybe you could sell the headers for enough to buy a set that wasn't coated. Just a thought. And yes thats what takes out O2 sensors with headers too. Thanks Bill

bentrod 01-15-2013 03:28 PM

Ok thanks ironpony maybe I'll get the SS ones. The price for the SS ones and the ceramic coated ones are the same, but they both say dont wrap with exhaust tape.

Seems like every headers I can find say that but IDK if that's just them protecting themselves from returns or if the exhaust wrap will actually make them rust out super early (I've never used exhaust wrap before)

I honestly dont care what they look like but dont want them to rust out with big holes in them after 5 years. Maybe I should post this question as a seperate topic...

ssimpala 01-15-2013 03:42 PM

Don't wrap them...it destroys them fairly quickly. Depending upon your application and how high you spin it, TriY's work almost as well as quad's. The Tri's have better low end torque but the quad's do better at high rpms. What headers are you looking at?

Ironpony 01-15-2013 03:54 PM

Headers and Cat
 
Yes the put that in there to protect their warrenty. And over time it will contribute to the early demise of your headers. How much time does it take. I don't know. And it would be unpredictable to try and figure out. And the point I was making before was what would cost more changing the headers every 5 or 6 years or changing the cats way more often. Maybe once a year? At least move the cats as close to the collectors as possible and hope for the best. And remember to fab some heat shields under them to help prevent fires if you drive on dry grass of in a field for instance. The shields top and bottom would also help keep heat in the cats. And I would make them so they kind of covered the collectors too. Thanks Bill

bentrod 01-15-2013 03:54 PM

hey ssimpala I'm not sure if i'm allowed to post this link but here it goes lol

Chevy 88 89 90 91 92 93 94 95 Truck Ceramic Headers 305 350 5 7L GMC Vortec | eBay

The truck is surely a low rpm highway truck. The ecm is set to cut fuel at 3200rpm.

Do you have a recommendation for triys? I'm pretty new to all of these different types of headers. Before today I only thought there were the shorties (block huggers) or longtubes.

Also when you mean destory will it really rot the tubes or does it just make them look ugly? (serious question because i dont know :confused:)

bentrod 01-15-2013 04:02 PM

ironpony sorry didnt see your post until now. I guess I would rather change the cat every so often rather than the headers.

I plan to make the ypipe from the headers out of 080 wall 304 like the one on there now, so I wouldnt mind wrapping that because I know it can take it. It's just the headers I was worried about.

Maybe wrap the cat too? I dont think ive heard of people doing that but maybe it'll help it last longer than a year.

ssimpala 01-15-2013 04:30 PM

Heartbreaker, I'm not familiar with those headers or that company. Sorry I can't help, except to say that you're probably better off with your stock manifolds for your particular use. Maybe someone else on here knows this company. Good luck, Bill. :)

oldbogie 01-15-2013 07:59 PM

Quote:

Originally Posted by heartbreaker440 (Post 1635172)
newish poster, long time lurker here.

I have an LT1 and would like to run mid/long tube headers and keep my cat on my daily driver, however I've read on the internet it seems that headers (specificly long tube) and a cat can cause problems like early cat fouling.

Does anybody here run long tube headers and a cat? Can you describe your setup? The LT1 in my truck does not have the AIR system so the cat would be a one in one out.

Any other thoughts or insight about this would be appriceated.

Need to insulate the pipes the cats need about 500 F going in. Read that you have shiny tubes, you're going to have to decide between shine or passing emissions. Living where I do I don't recommend ceramic coatings on the headers for a daily driver as they generally won't survive the winter.

Bogie


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