Ok so I will be doing the exhaust on my T/A coming up. Its non computer carbed motor. Im gonna swap to headers, unsure of long or short but thats beside the point. After reading a bunch of threads its seems many people are very passionate about using a "cat"....I have no problem with this but just curious why? Where I am there are no emissions regs, my dd truck is a diesel and the cat is one of the first things that comes off when modding but my car will be soaking up alot of the miles that my truck sees. Should I use a cat in my exhaust? Is there any harm or loss to be had in using or not using one? It would be cheaper to not use one but besides that.....

 

I did not know diesels used a cat. But the point of a catelic converter on a gasoline engine is to burn/clean the exhaust gases. It makes the emissions much better. And it drastically helps improve overall air quality.
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you will loose about 1% of your HP, but your kids will inherit a cleaner enviorment.

 

I get what your saying....though this seems like a new thing to me. Back when I drove/modded gassers it seemed "cats" were not so popular.

 

If your really worried about losing power, get a highflow cat.
Pretty sure you can get one from summit or jegs for around 100.
It may not be as good as a stock cat, as far as how well it works.

It's not that it's legal or your state dosen't have any laws or anything saying you have to have one.
Every car built after I think 79 not sure, in the states, legaly has to have a cat for street use.
That is because it's a federal law. Some states just don't care.

 

The old style or OEM "cat's" suck major hp, like 5-7%, so on a 300 hp motor you are loosing 18-21HP that sucks. But with a modern high flow cat you will only loose 1-2%, 3-6hp worth it for better air quality.

 

I`ve been considering getting a high flow cat on my car.It currently doesnt have one,or any other emmissions equipment.The cam I use has enough overlap to function as a self egr from all I`ve read and been told.I`ve talked to people who have sniffer but no visuals and they said they have passed with egr and highflow cat as only emmissions equipment.I would like to run a little cleaner but How would I know if I am or if the equipment is even working properly If no one even does any testing within 500 miles?

 

Next time you take the car on a road trip.
Keep it running good.

 

New cats dont need a air pipe, just get it close enough to the headers so it stays hot. That is all you need.

 

There have been tests showing that cats actually expel worse emissions than what an engine would normally produce. I saw these test results several years ago so they are probably gone by now but you might find something on Google if you search hard enough.

 

There have also been "tests" showing you can drive a car on water.

 

Then what seems to be the problem?

 

Cats work. They clean up the air. They have been proven to work over the last 30 + years of experience. If you were in Los Angeles in the early 80 versus now you would realize that the EPA regulations while a pain in the *** work. It is not some government consperieacy to kill hp. They are the pain in the ***. They look ugly; they soften the tone of the exhaust. But the new z06 makes 600+ hp through like 3+ cats.

 

So nothing about moving away from large mostly steel land barges with large, innefficient v8s with carbs or "primative" and unneffective efi and poor aerodynamics to small, light, modern cars with very efficient engines and modern day electronics has anything to do with the reduction in smog?

I am not saying that cats don't reduce emmissions, I am saying that supposedly what they do produce is worse than what goes into them.