Discussion in 'Exhaust' started by 1996 yukon, Dec 30, 2009.
Could I make a y-pipe from a k2500 4.3 fit my k1500 4.3??
I've got the stock headers and y-pipe going to 3" piping to the stock cat, then cut. If i replaced the cat with a flowmaster or a thrush, would the engine have enough backpressure or would that be too little? The cat is clogged and sounds like sh!t, but i dont want to put the piping back on, i like it cut.
I have never seen a 2500 4x4 with a 4.3.
Back pressure is a myth, an engine does not need it. Where that has been confused is with scavenging. My suggestion to you is to look up "engine scavenging effect" for yourself rather than rely on someone else's information in this thread.
The only situation you would ever need more back pressure then what the engine puts out right from the heads is maybe if you had just built the engine and wanted more back pressure to make sure the valve train is set right.
One thing to keep in mind though, is that the whole point of having better flowing exhaust, is to allow air to flow through your engine better. If you don't have a stream of air coming into your engine that matches the flow of air you have leaving it, you're just wasting your money going huge with your exhaust.
That's probably why it runs like crap then. I've got decent airflow, but the cat is seemingly clogged. I'm going to be opening up the airflow a little as a little project, and i want the exhaust to be free-flowing too, but not anything crazy like 3" straight pipe.
You could even just cut the shell off of the cat and weld it onto a new pipe. So there wouldn't really be a cat there at all, just looks like it. I'm pretty sure you guys only do visual inspections in Texas.
It could, I was just confessing that I've never seen one so I can't verify any of it. But, that said, a 4.3 and 5.0/5.7 all use the same parts. A 4.3 is nothing but a 350 with two cylinders lopped off. You might be able to go with a 4.3, 5.0 or 5.7 part number and be fine.
No I lived in Houston for 4 years, it has to pass a sniffer.
Good call. They do both.
Then it looks like a high flow is the route for you.
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